Castiel

==History==
Castiel is an angel. He manifests on Earth inside his vessel, Jimmy Novak. He is the only angel that is shown to have been resurrected after having been killed, and he has been resurrected more than once.
Many angels laid siege to Hell to rescue Dean, but it was Castiel who ultimately pulled Dean out. According to Castiel, he did so "Because God commanded it." His hand print was burned into Dean's left shoulder. Castiel is amongst a group of angels who manifest on Earth to stop the breaking of the the 66 Seals which will release Lucifer and start the Apocalypse. Over time he develops an empathy for the Winchesters, in particular Dean. When he learns that Michael actually intends for Lucifer to be released so he can kill him, Castiel tries to warn Dean, but is punished. Ultimately he breaks allegiance with Heaven to side with humanity.
With Lucifer free, and Castiel cut off from Heaven's power, he decides to try and find the long absent God. When he learns God is not interested in intervening to stop the Apocalypse, he is devastated. He works to support the efforts of Sam, Dean and Bobby in stopping the battle between Michael and Lucifer.
After Sam's sacrifice to defeat Lucifer, Castiel tries to rescue him from Lucifer's Cage, but fails to retrieve Sam's soul. In an attempt to prevent Raphael from restarting the Apocalypse, Castiel is tempted into an alliance with Crowley. The demon offers to help find Purgatory which can provide them both with great power. His efforts mean Castiel becomes increasingly distanced from the Winchesters as he hides his efforts from them, to the extent of breaking Sam's mind in order to hinder their pursuit of him.
After taking in the souls of Purgatory, Castiel kills Raphael. He claims that he is no longer an angel, but the new "God." After smiting many people he considered to be doing evil in God's name, he blacks out and loses control of his vessel, and his powers, to Leviathans possessing him. Conceding to Dean and Sam's wishes, Castiel attempts to return all the souls and entities inside him to Purgatory.
After the souls leave Castiel, he apologizes to Dean, and pledges to find some way of redeeming himself. His plans are cut short when the Leviathans, who managed to hold on, take over his vessel. As the vessel rapidly deteriorates, the Leviathans march it into a reservoir, where it disappears beneath the water, releasing them.
Castiel is later found wandering naked in the woods near the water with no memory of who he is by Daphne Allen, who claims that God led her to him. She takes him home, he takes on the name Emmanuel Allen, and they marry. He discovers he has a gift for healing.
While searching for a way to help Sam, whose psychosis is killing him, Dean hears about Emmanuel from another hunter, and is shocked to discover it is Castiel. Castiel eventually regains his memories, and is horrified at what he did. He tries to heal Sam, but unable to do so, he chooses to take Sam's madness into his own mind.
After becoming catatonic for a time, Castiel awakes crazed but cognizant when the Word of God is uncovered, and he helps Sam and Dean identify the tablet. He later aids Dean in killing Leviathan leader Dick Roman, and in the ensuing explosion is pulled into Purgatory with Dean, where Castiel disappears. A year later, when Dean escapes Purgatory, Castiel is not with him, and Dean tells Sam that Castiel "didn't make it," having "let go" in Purgatory when things "got hairy" not long before Dean escaped. Its revealed that in being in Purgatory restored Castiel's sanity and that while he helped Dean escape, he remained out of his own free will as he chose to stay in Purgatory as his penance for his sins. However, angels led by Naomi rescued him and Castiel was rescued, in a somewhat weakened state and under orders that he is unaware of to aid the Winchesters and report into Naomi periodically.
Although he eventually managed to escape Naomi's control, he was subsequently manipulated by exiled angel Metatron into completing a ritual that banished all angels from Heaven, the same ritual concluding with Metatron taking Castiel's grace and leaving him a human. After some time forced to make a life for himself as a human, made more complicated by Dean's decision to reject Castiel to take Heaven's attention away from Sam, who was still healing from damage he sustained during the trials, Castiel was able to regain his angelic status by stealing the grace from the angel Theo.
Despite Metatron's attempts to paint Castiel as the villain of the piece, he is eventually able to prove to the other angels that Metatron sees them as nothing more than fools to be manipulated and tricked, Gadreel's sacrifice allowing Castiel to trap Metatron in Heaven's prison. Although his stolen grace would eventually kill him, Castiel's life was saved when Crowley killed the angel Adina to transfer her grace to Castiel. After curing Dean of his transformation into a demon, Castiel briefly reunites with his former vessel Claire Novak while working to resolve the conflict in Heaven. However, he is left on the run from Heaven once again when he extracts Metatron from Heaven to question him about a cure for the Mark of Cain. Even after taking Metatron's grace to question him about a possible cure, Metatron reveals that he actually doesn't know of a cure, but agrees to show Castiel to the location where he left the fragments of Castiel's original Grace in return for his life. Although Metatron escapes with the Demon Tablet, Castiel is able to recover his grace and restore some of his power.
==Characteristics==
Castiel manifests on Earth through possession of a vessel - in his case Jimmy Novak. On one occasion, Castiel describes his true angelic form as a "multidimensional wavelength of celestial intent"; on another, he says that his true form is the size of the Chrysler Building in New York, which is 1047 feet (319 m) in height.
The sight of Castiel's true form will burn out a human's eyes, as Pamela Barnes found when she tried to summon him in a séance. Castiel's true voice, like the true voices of other angels, is piercing to the human ear. He communicates with his vessel Jimmy through the electronics in his home, and appears to use an analogous method to communicate with Dean and Sam in Heaven. Castiel can also speak to his vessel unaided; he converses with Jimmy to obtain his consent to serve as a vessel. Castiel, using his vessel, can easily overpower and kill demons, sometimes even groups of them, by touch.
Castiel is able to teleport himself, and in some cases groups of people, through time and space. He can cover great distances in a matter of seconds, as shown in 6.06 You Can't Handle the Truth when he believes Gabriel's Horn of Truth has been discovered, and searches an entire city in moments. The angel possesses vast occult knowledge, ranging from lore, to spells cast in Enochian, to the structure and defenses of Hell. Cas can move objects with a gesture. Castiel is also proficient with an angel blade, generally outmatching his angelic opponents while using it.
Castiel rank in the Host of Heaven has varied, and the abilities he displays have varied based on his changing status. Castiel states that he was once the captain of his garrison. In the past Anna Milton, in her angelic state, was his superior in their angel garrison. Uriel appears to be junior to him, until he is promoted when Castiel's superiors become concerned about Cas' empathy for Dean.Zachariah was also his superior. However, Castiel seems to have been higher in rank than the henchmen that often accompanied Zachariah. Castiel indicated that he had been cut off from Heaven after helping Dean escape from Zachariah, meaning that he lost some of his abilities, including the power to heal. After banishing himself and a group of other angels, Castiel loses more of his powers and appears almost mortal at the end of season five. Castiel states on one occasion that he is now a Seraph and as a result, seems to hold onto all of his powers even though he is a fallen angel and cut off from Heaven again. However, since returning from Purgatory, his powers are weakened, leaving him exhausted when he uses his major abilities. However, this seemed to be a temporary effect as he has since shown his powers with no ill effect.
As an angel, Castiel has the ability to resurrect the dead, though the strength of this ability has varied over time. By leading an incursion of angels into Hell, Castiel was able to retrieve Dean's soul and then resurrect him on Earth. Though he lost this power along with the majority of his other abilities, Castiel regained it following his second resurrection and was able to bring Bobby Singer back simply by touching two fingers to his forehead.When Crowley threatened to kill the Winchesters, Castiel simply told him that he would resurrect them again if Crowley did so. After losing and regaining his grace, Castiel's ability to resurrect the dead was severely impeded. After Sam's death in Apocalypse World, Castiel and Gabriel told Jack Kline that they both lacked the strength to bring him back. During the planning stages for saving Jack, Castiel stated that he could resurrect him, but he would only be able to bring him back for a short period of time and doing so required Castiel to go to Heaven and find Jack's soul. When Jack was resurrected, he continued to display the condition that killed him in the first place, Castiel having been unable to fix it. It was only when Jack used a spell provided by Lily Sunder to cure his condition that his resurrection become permanent.
Castiel has been killed six times, once by Raphael, twice by Lucifer, once by the Leviathans, once by a reaper named April Kelly who was hired by Bartholomew, and once by the Cosmic Entity residing withing the Empty, and he is subsequently resurrected each time. After he died and returned the second time Castiel stated that he believes God brought him back "new and improved," by the third time he began to see his resurrections as punishments for all he's done. He is able to heal others with a touch and resurrect people at will., He demonstrates pyrokinesis when he burns "Crowley's" bones. Later, Castiel shows the ability to incinerate lesser monsters, such as the vampire Lenore, by touch. He also releases a blast of white light from his palms that instantly kills anything that sees it. It is also implied that he can kill even powerful demons with ease, including Crowley, the King of Hell, he is even able to force one back into its meatsuit to kill it. Despite his improved abilities Castiel remains unequal to an archangel, as Raphael can block his attempt to kill Crowley, as can Eve and the Leviathans.
He also displays the unique ability to tell the Leviathans apart no matter what form they take. According to Meg this is due to the Leviathans briefly using him as a vessel, which allows him to know them "better than anyone." He also displays the ability to sense the presence of nearby Leviathans before they become known to anyone else.
While originally aiding the Winchesters mainly with cases related to angels and demons, Castiel sought to become a hunter himself following his return from Purgatory. However, though Castiel was helpful on his first case, he wasn't very good at being a hunter.Though he proved able to provide backup on several regular cases and even hunt Lucifer with Crowley as his partner, when the Winchesters were arrested by the Secret Service, Castiel tried to hunt vampires on his own, but lacked the skills to locate them and had to give the case to Mary Winchester. Castiel's effectiveness as a hunter for most of his career is mainly as backup in situations, though over time his skills have increased significantly. Following the birth of Jack and his own resurrection, Castiel acted as a full hunter on a ghoul case, displaying a knowledge of the lore surrounding the creature and a better ability to blend in as law enforcement than on previous occasions, though he still remained somewhat awkward at it. Following the return from Apocalypse World, he was able to act as a part of Sam's hunter network, backing up hunters other than the Winchesters on cases. While dealing with the Hell Ghosts, Castiel proved able to use a shotgun and rock salt in battle without issue, a change from the time he struggled to understand the purpose of such a weapon while going up against Niveus Pharmaceuticals. While on vacation, almost two years after his last known attempted solo case, Castiel proved himself to have grown into a skilled hunter in his own right, able to interact effectively with law enforcement on his own, go through case files, determine what type of monster he was dealing with, figure out its pattern and determine a possible location for its lair all without help from the Winchesters or other hunters.
With Heaven failing and the angels nearly extinct, Castiel's powers have begun failing him. This has been going on for some time, though Castiel states that Dean has never listened when Castiel has tried to tell him this. Presumably as a result, he is unable to heal Arthur Ketch of two gunshot wounds and struggles with healing a boy of a leg injury.
When Dean reunites with Bobby in Heaven, he reveals that Jack revived Castiel following God's defeat to help in reshaping Heaven for the better.
===Powers And Abilities===
Castiel's powers change over time for a number of reasons, such as when he is disenfranchised by Heaven in season five and when the angels are expelled from Heaven by Metatron.
* Dreamwalking - Castiel has been shown to be able to enter the dreams of humans to communicate with Dean Winchester.
* Healing - He can heal physical and mental damage.
* Mind control - Castiel was shown to be able to manipulate the minds of Secret Service agents to forget he saw him or the Winchesters.
* Clairsentience - Castiel is able to perceive the true visages of angels and demons, as well as to pierce through the Veil.
* Psychic - He can undertake what Dean refers to as a Vulcan Mind Meld in order to read thoughts. Castiel also has the ability to sense if someone is lying, however, due to the truth being situational at times, the accuracy of this ability can be in question.
* Pyrokinesis
* Prayer - Castiel, like all angels, can hear the prayers of any humans, which also allows for angels to locate the person. As revealed to Claire Novak, the prayer does not need to be formal, and can be simple feeling of longing or the need to talk.
* Resurrection - So long as he has a connection to Heaven, Castiel can resurrect the dead. Castiel has been able to resurrect Dean Winchester, Bobby Singer, and Jack Kline. However, his power to resurrect the dead has been greatly weakened since the Fall, leaving Castiel unable to bring Jack back for more than a few moments without Lily Sunder's Enochian magic to cure Jack's condition afterwards and make the resurrection permanent.
* Regeneration - Short of being stabbed in a fatal area with an angel blade, Castiel has the ability to mend all wounds incurred to his vessel.
* Sedation - With a touch, Castiel is able render anyone unconscious.
* Smiting - He can smite black-eyed demons with general ease.
* Super strength and endurance - As an angel, Castiel's strength exceeds that of human and demon, having shown the ability to punch Uriel through a brick wall in the past. After the Fall, however, Castiel and all angels have shown more susceptibility to physical damage.
* Telekinesis
* Teleportation - As an angel, Castiel was capable of teleporting anywhere in existence. After the Fall, Castiel, along with the rest of the angels, lost his wings and ability to travel and was forced to take up more conventional means.
* Time Travel - Due to the fluidity of time, Castiel is able to bend it on occasion, traveling backwards in time. However, the act of time travel can be strenuous on angels. After the Fall, Castiel and all other angels have lost this ability, except for archangels.
* Universal communication - As an angel, Castiel is capable of understanding any language in the world, including that of animals.
===Weaknesses===
* Angel blades - Can cause severe injury and death to all angels. Castiel is the only angel in creation to have been resurrected after being fatally stabbed with an angel blade.
* Archangels - Archangels can overpower and smite Castiel.
* Higher demons - White-eyed Demons and Princes of Hell can overpower Castiel.
* Holy fire - Like all angels, Castiel is incapable of crossing holy fire, which has the ability to kill him.
* Lance of Michael - Forged by Michael to kill Lucifer, being pierced with the lance will lead to an angel dying a drawn-out and agonizing death.
* Spells - Castiel reveals to Meg that a book with the proper spells could theoretically kill him.
* Warding sigils - Like all angels, Castiel is susceptible to strong warding.
===Personality===
Because he was an angel, Castiel initially expressed almost no emotion towards humans, and had little room for disobedience or feelings, as he was driven to follow his orders, although he does reveal some doubts about the morality of his orders, expressing an appreciation for the beauty of humans as God's creations. As he spends more time with Dean, he develops empathy and affection for him, and eventually for those close to him, and humans in general. Castiel's superiors begin to question his loyalty and promote Uriel to oversee him. Castiel eventually rebels against and is ostracized from heaven, leaving him deprived of most of his angelic abilities, forcing him to interact more with humans than he had previously. He is often confused by the finer details of human interaction and is blind to social norms. He allies himself with Dean, and despite his despondency over the absence of his maker and their desperate situation, Castiel continues to fight against the Apocalypse.
After his second resurrection by God, with enhanced abilities, he sees his decisions and support of freewill to have been affirmed. Castiel begins to show pride, while remaining somewhat naive with regard to consequences. Crowley is able manipulate this budding sense of pride to get Castiel to start the angelic civil war. Castiel becomes dedicated to his own decisions, and tends to pass over other opinions, even Dean's, in the absence of another clear course. He eventually double-crosses Crowley, taking in the souls of Purgatory alone. He then insists on worship from his former friends. He intends to be an involved god, a better and loving god who will not abandon the world. He renounces his dedication to free will, saying that angels need a firm hand. He is quick to smite those he feels to be hypocritical and unjust, and rewards those who have faith. However, Castiel is being influenced by entities inside him - including leviathans - and his actions become erratic and violent. He realizes he is not strong enough to contain the power, and at a prompt from Sam, he goes to the brothers for help. He is apologetic and humbled; after the souls are out of him he wants to find a way to redeem himself before the brothers. He eventually takes Sam's madness on himself, freeing Sam.
In episode 5.14 My Bloody Valentine, Castiel shows his deep affection towards raw meat, eating it in the room and unable to get to famine, one of the four horsemen. Here, we realize that Castiel's vessel, Jimmy Novak is desiring the food which he cannot gain access to with the angel possessing him.
Castiel's insanity after taking on Sam's memories of Hell seems to free him of some of his guilt, though it leaves his mind scattered. He was unwilling to fight due to his belief that he is a "jinx," though Dean convinces him to help kill Dick Roman. He also expresses some fondness for Meg despite the previous animosity that existed between them. However, after getting trapped in Purgatory, Castiel seemed to have regained his sanity, though he admitted there is no way to know for sure. However, his experiences have changed his personality somewhat and he is no longer as aloof as he usually is and has displayed a fondness for human things he took for granted such as watching television, which he never understood before.
==Debut In==
===4.01 Lazarus Rising===
:"I'm the one who gripped you tight and raised you from perdition."
When Dean wakes up in the woods, no longer in Hell, he goes to find Sam and Bobby. While stopping at a gas station for supplies, Dean is overcome by a piercing noise as the windows shatter around him. Once Dean gets to Bobby's and confirms that he is really himself, the two find Sam and speculate how and why Dean returned. After visiting a psychic friend of Bobby's (Pamela), they discover this creature is called Castiel, but also that it is very powerful; a single glimpse burnt out Pamela's eyes. After summoning Castiel in a warehouse. After rock salt and Ruby's knife prove ineffective, Dean asks who he is, to which Castiel replied that "I am the one who gripped you tight and raised you from perdition." Confused, Dean presses what Castiel means by this, Castiel shows Dean the shadows of his wings and telling him that God has work for Dean to do.
===4.02 Are You There, God? It's Me, Dean Winchester===
:"We tried. And there are other battles, other seals. Some we'll win, some we'll lose. This one we lost. Our numbers are not unlimited. Six of my brothers died in the field this week. You think the armies of Heaven should just follow you around? There's a bigger picture here. You should show me some respect. I dragged you out of Hell. I can throw you back in."
Castiel appears to Dean in a dream set in Bobby's kitchen, and confirms that the spirits who attacked them were Witnesses. He tells Dean that Lilith summoned them, and that in so doing she broke one of the 66 Seals. He explains that the angels are fighting to keep the other seals intact, because when the last one is broken, Lucifer will be freed.
===4.03 In The Beginning===
:"Destiny can't be changed, Dean. All roads lead to the same destination."
Castiel sends Dean back 1973 to meet his parents when they were young. The purpose of this was to show Dean the truth of what happened with Mary Winchester and Azazel. Castiel explains that the angels still have no idea what Azazel's endgame is. He then tells Dean that Sam is headed down a dangerous road and that if Dean doesn't stop him, the angels will.
===4.07 It's The Great Pumpkin, Sam Winchester===
:"I’m not a… hammer as you say. I have questions, I have doubts. I don’t know what is right and what is wrong anymore, whether you passed or failed here. But in the coming months you will have more decisions to make. I don’t envy the weight that’s on your shoulders, Dean. I truly don’t."
Dean and Sam return to their motel room to find Castiel and Uriel waiting. Sam is thrilled to meet Castiel. Castiel's response is to acknowledge Sam as the "boy with the demon blood" and says that he is glad Sam is no longer using his powers. Castiel reveals they found a hex bag, which would've killed the boys, secreted in the room. He then tells them that the raising of Samhain by the witch will break another of the 66 Seals. He advises Sam and Dean to leave town because he and Uriel are going to destroy it. Sam and Dean argue that they can find and kill the witch and stop the summoning of Samhain.
Later Uriel expresses his contempt for humans and tries to persuade Castiel that they should destroy the town anyway. Castiel reminds him that Dean was saved because he has "potential," and reminds Uriel that they must follow their "true orders."
After Sam has used his powers to send Samhain to Hell, Castiel appears to Dean. He reveals that their true orders were to follow Dean's decision, as a test under battlefield conditions. Dean, thinking he's failed, asserts that he'd make the same decisions all over again if he had to, because of what he and Sam have saved. Castiel confides that he was praying Dean would choose as he did, and that he respects and loves humans as God's creations. He also admits that he has doubts about the plan from Heaven, and is no longer sure what is right and what is wrong. He warns that in the coming months, there will be more hard decisions for Dean -- and the angel does not envy him that.
===4.09 I Know What You Did Last Summer===
:"We're here for Anna."
After Sam, Dean and Ruby save Anna from demons, Castiel and Uriel burst through the cabin door, telling Dean they are there to kill Anna.
===4.10 Heaven and Hell===
:"You know who we are and what we will do. I won't say it again. Leave now... or we lay you to waste."
Castiel and Uriel appear and demand that Sam and Dean hand over Anna, with Castiel announcing, "We're here for Anna...she has to die." Uriel states that Anna is not as innocent as she appears. The boys protest but the angels attack. Suddenly a bright light engulfs them and the angels are repelled and disappear. The boys go to the room where Anna was hiding, and find that she has used her blood to draw an angel banishing sigil on the mirror and banish the angels.
Uriel and Castiel reappear from being banished later to take Anna. Dean's choice is revealed: either Anna dies - or Sam. As the angels are about to take her, an injured Ruby appears with Alastair. The demons and angels confront each other and a fight ensues. During the confrontation Castiel faces off with Alastair, landing several blows and trying to cast the demon back into the Pit. It proves ineffective and Alastair pins Castiel to the ground, strangles him and starts a demonic chant. Castiel is saved from Alastair's grip when Dean hits the demon across the back with a tire iron and distracts him from Castiel.
During the fight Anna steals her grace from Uriel and becomes an angel again. During her transformation, Alastair disappears and his host is destroyed. Uriel and Castiel leave, and it is discovered that Sam had planned all along to bring the demons and angels together to get them to fight each other.
===4.15 Death Takes A Holiday===
:"To everything there is a season."
Castiel, pretending to be Bobby Singer, tells Sam by phone about a scenario described in a version of Revelations:
:And he bloodied death under the newborn sky
:Sweet to taste
:But bitter once devoured
This is one of the 66 Seals which will be broken if two reapers are killed under a solstice moon. Castiel needs Sam and Dean to prevent the killing because the demons responsible are holed up in a refuge covered in Enochian sigils that prevent angels from entering. The boys are successful in preventing the seal from being broken, and in the process Castiel captures Alastair.
After talking with a reaper, Dean asks Castiel why, if death is part of the natural order, he was rescued from Hell. Castiel replies "You're different."
===4.16 On the Head Of A Pin===
:"I think maybe our Father isn't giving the orders anymore. Maybe there is something wrong."
In the first scene, Castiel finds an angel from his garrison dead.
Castiel and Uriel then appear in the Winchesters' hotel, explaining to Dean that the torturing skills he learned in Hell are required to break Alastair so that they can identify which demon is killing angels. Dean refuses to accompany them, but Uriel and Castiel transport him to the place where Alastair is kept in spite of this protest.
Once there, Dean insists on speaking to Cas alone. Uriel departs. Castiel then explains that he has been placed under Uriel's authority because his superiors feel he is too emotionally involved with the Winchesters. They believe that this is impairing his judgment. Castiel tells Dean that the angels need, rather than want, him to do this. Dean is convinced, and enters the room where Alastair is held. Castiel waits outside, listening.
Anna arrives and attempts to convince Castiel that forcing Dean into torturing again is morally wrong, and that it could not truly be God's orders. Castiel is clearly uncertain. Anna approaches him, explaining that she felt doubt before she left Heaven. She tries to persuade him that together they could find an answer. Castiel backs away from her, insisting that they have nothing in common because she fell. He tells her to leave, and she does.
Meanwhile, Alastair is freed from the devil's trap and attacks Dean. Castiel enters the room and fights him, but Alastair manages to trap him. Alastair then begins to chant a demonic spell to send Castiel back to Heaven, but Sam interrupts him using his demonic powers, saving Castiel. Alastair is killed by Sam after insisting that no demon is responsible for the deaths of the angels.
Later, Castiel confronts Sam at the hospital where Dean is being treated. Sam assures Castiel that Alastair was not lying.
Uriel and Castiel meet at a playground to talk about how "something is wrong" in Heaven. Castiel then calls Anna and tells her that he is considering disobedience; however, he does not believe it is "good." He asks her to tell him what he should do, but she refuses, reminding him that he had thought her help beneath him a short while before. She tells him to make his own decisions.
Castiel returns to the warehouse where Alastair was kept and finds out that a leaky pipe enabled Alastair to escape from the devils trap. Uriel arrives while Castiel is examining the trap. Castiel declares that he built the old Enochian trap, and insists that a demon could not have defeated it. He demands to know the truth. Uriel admits that he was responsible for the deaths of the 7 angels, and that he wishes Lucifer to rise and humanity to be destroyed. He has been converting other members of the garrison to this viewpoint, and killing those that disagreed. Uriel attempts to recruit Castiel, but fails, and Castiel attacks him. Uriel fights back, bringing Castiel to his knees. Anna arrives clandestinely and stabs Uriel from behind, saving Castiel.
Castiel visits Dean in the hospital and confirms that Dean's actions in Hell resulted in the breaking of the first seal. When Dean asks why he was not left in Hell, Castiel responds that "the righteous man who begins it is the only one who can end it."
===4.18 The Monster At The End Of This Book===
:"If anything threatens a prophet, anything at all, an archangel will appear to destroy that threat. Archangels are fierce. They're absolute. They're Heaven's most terrifying weapon."
Sam and Dean have encountered Chuck Shurley, a man who has written detailed accounts of the Winchesters' lives. Everything Chuck writes seems to come true. When Chuck predicts that Sam will encounter Lilith, Dean, afraid for Sam, angrily insists on an explanation of the writings. He threatens Chuck with violence, but Castiel arrives to stop Dean and reveals that Chuck Shurley is a Prophet of the lord. His books will one day be known as the Winchester Gospels. As a prophet, Chuck must not be harmed.
Dean returns to his motel to find that Sam has burned the protective hex bags Dean made. He is seeking the confrontation with Lilith that Chuck foresaw. Frustrated, Dean threatens to leave Sam to his fate, but changes his mind and instead storms out into the parking lot. Desperate, Dean starts to pray and Castiel appears, pleased by the sign of faith. Dean asks for help in preventing what Chuck has predicted, but Castiel refuses to interfere directly, saying that what a prophet has seen will come to pass. However, Castiel explains that Chuck is watched over by an archangel that will annihilate any threat to the prophet, including a demon like Lilith. Dean thanks him and uses the information by putting Chuck in the same room with Lilith as she and Sam are about to fight. This causes the archangel to appear, and Lilith flees.
===4.20 The Rapture===
:"I wanna make sure you understand. You won't die or age. If this last year was painful for you, picture a hundred, a thousand more like it."
Castiel appears in a dream to Dean, and asks him to meet him in the real world because there is something he needs to tell him. When Dean and Sam arrive at the address provided by Castiel, they find signs of a violent confrontation. They encounter Castiel's vessel, Jimmy Novak, and determine that Castiel has been taken back to Heaven by force.
Castiel's vessel Jimmy Novak remembers little, but describes being possessed by Castiel as being "chained to a comet". Jimmy is anxious to return to his family. Sam and Dean try to prevent him from leaving, but Jimmy escapes. He returns home, but demons soon intrude, trying to capture the "empty vessel." Sam and Dean help the Novaks to escape, but the demons capture Jimmy's wife and his daughter, and offer to trade their lives for his.
Jimmy goes to meet the demons and is shot as a captive Sam and Dean watch. Suddenly Castiel returns, possessing Jimmy's daughter Claire Novak. She, like Jimmy, is an angelic vessel, having inherited the something "is in his blood" that made Jimmy a vessel. After defeating the demons, Castiel agrees to Jimmy's dying plea that Castiel use him as a vessel instead of his daughter.
As Castiel leaves, Dean asks him what it was he wanted to tell them, but Castiel rebuffs him, saying that he learned his lesson in Heaven. He doesn't serve man...or Dean, only Heaven.
===4.21 When The Levee Breaks===
:"Consuming the amount of blood it would take to kill Lilith would change your brother forever. Most likely, he would become the next creature that you would feel compelled to kill. There's no reason this would have to come to pass, Dean. We believe it's you, Dean, not your brother. The only question for us is whether you're willing to accept it. Stand up and accept your role. You are the one who will stop it"
After discovering that Sam has been drinking demon blood, Dean and Bobby imprison him in Bobby's panic room. Dean calls on Castiel, demanding to know if Sam is capable of killing Lilith. Castiel says yes, but that consuming the amount of demon blood required would make him inhuman. Castiel reiterates that the angels believe Dean can be the one to stop the apocalypse, rather than Sam, and asks if Dean will accept that role. Dean agrees for Sam's sake, and swears fealty and obedience to God and the angels at Castiel's insistence.
Later Castiel comes secretly into Bobby's house and uses his powers to release Sam's bonds and open the door to Bobby's Panic Room. Sam escapes, and Castiel leaves. Anna visits Castiel at a waterfront, and confronts him over his actions, but he says he is acting on orders. He tells her that she should not have come to see him, and she is taken captive by other angels.
===4.22 Lucifer Rising===
:"What is so worth saving? I see nothing but pain here. I see inside you. I see your guilt, your anger, confusion. In paradise, all is forgiven. You'll be at peace. Even with Sam."
Castiel and Zachariah hold Dean captive in the Green Room, waiting as the apocalypse approaches. Dean pleads with Castiel to let him see Sam, but Castiel refuses, saying that it is not advisable. The doors of the room are removed to prevent Dean's escape.
Later, after Zachariah reveals the angels' real plan, Castiel returns and apologizses to Dean for deceiving him. Dean is angry, and argues with Castiel, trying to convince him to help stop the apocalypse. Cas initially refuses, arguing that they would all be hunted. They argue, and Cas leaves. He then returns abruptly, forces Dean against a wall, and signals for silence. Cutting his forearm, Cas draws a sigil on the wall in blood. Zachariah arrives to stop him, but Castiel places a bloody hand on the sigil and Zachariah is sent away. Castiel says he will take Dean to Sam to stop him from killing Lilith - because her death IS the final seal.
Castiel and Dean visit Chuck Shurley, who has foreseen that Sam is at the Convent. An archangel arrives, and Castiel says he will hold it off and sends Dean directly to the Convent. Castiel and Chuck wait for the archangel as the house continues to shake.
===5.01 Sympathy For The Devil===
:"Alive? That's a good question. How did these two end up on that airplane? Another good question. 'Cause the angels didn't do it. I think we both know the answer, don't we?"
Early in the episode, the Winchesters visit Chuck Shurley to discover what happened to Castiel when the archangel attacked at the end of 4.22 Lucifer Rising. Chuck reveals that Castiel was killed, that he exploded "like a water balloon of chunky soup."
After luring the Winchesters to their father's storage unit, Zachariah reveals that Dean is the archangel Michael's vessel. Dean refuses to act as a vessel, so Zachariah tries to coerce Dean's agreement by torturing both Dean and Sam. Suddenly, Castiel appears. He attacks the two angels Zachariah brought with him, killing both with an angel blade. He then orders Zachariah to heal Sam and Dean, then leave. Zachariah complies.
Castiel informs the brothers that Lucifer is preparing to take a vessel and that they must be on their guard. He touches Sam and Dean, burning Enochian sigils into their ribs that will hide them from all angels, including Lucifer. When asked what brought him back to life, Cas does not answer, and vanishes.
===5.02 Good God, Y'All===
:"I killed two angels this week. My brothers. I'm hunted. I rebelled and I did it -- all of it -- for you. And you failed. You and your brother destroyed the world. And I lost everything -- for nothing. So keep your opinions to yourself."
Castiel calls Sam to find out where the boys are; he cannot locate them because the Enochian sigils he etched into their ribs hide them from all angels, including himself. He meets them at the hospital where Bobby is being treated. He reveals that he is cut off from Heaven following to rebellion, and has lost some of his powers, including the ability to heal. This means that he cannot help Bobby. He then says that in order to defeat Lucifer he plans to find God. He asks Dean for his amulet, which Cas says will burn hot in God's presence. Dean mocks Castiel's plan, and Cas responds angrily, detailing what he has done for the Winchesters and what he has lost as a result. Dean relents and gives him the amulet, with orders not to lose it.
===5.03 Free To Be You And Me===
:"If God is dead, why have I returned? Who brought me back?"
Castiel visits Dean in a hotel room to ask for help. He wants Dean to help him find Raphael, the archangel who killed Castiel. Cas hopes to trap and interrogate Raphael, forcing him to divulge the location of God. Castiel also says that he is asking because Dean is "the only one who'll help me". Dean agrees to go along, but only if they drive. Cas and Dean arrive in the Maine town where Raphael was sighted and go to the local sheriff for information. Cas wants to tell the sheriff about Raphael, but Dean persuades him that the truth is not a good idea in this situation. He gives Castiel an FBI badge and straightens his tie.
After an awkward (and amusing) conversation with the sheriff, they discover that Raphael's vessel has been taken to a local hospital. Cas decides to trap Raphael using a very dangerous ritual involving holy oil obtained from Jerusalem. He admits to Dean that even though Dean, as Michael's vessel, will not be harmed, Castiel may not survive. Dean considers this, and asks Castiel what he would like to do on his last night on Earth. Dean throws out a few suggestions, and discovers from Cas' reactions that the angel is a virgin. In response, Dean takes Cas to a brothel. At a table in the bar area, Castiel looks terribly uncomfortable. Dean orders him to relax, to no effect. A girl comes over and Dean introduces her to Castiel. She leads the nervous angel to a back room, leaving behind a bemused Dean. A few moments later, a scream from the back sends Dean in search of Cas, who is being yelled at by the frightened sex worker. It seems that Cas tried to comfort the girl by telling her it wasn't her fault that her father ran away; it was because he hated his job at the post office. Dean laughs, and the two of them run as a pair of bouncers appear.
The next morning, Dean and Castiel place Raphael's vessel in a circle of holy oil in his room at the hospital. Castiel chants in Enochian to summon Raphael, then lights the oil. Raphael does not manifest, and hours later Dean and Castiel return to their base in an empty house. Raphael, occupying his vessel, is inside when they enter. He threatens to take Dean to Michael, but Dean lights a hidden circle of holy oil, trapping the archangel. Castiel and Raphael argue, with Raphael insisting that God is dead. Castiel refuses to believe him, and he and Dean leave Raphael trapped in the circle of fire. Later, Castiel says he believes God is out there, and that he will keep searching.
===5.04 The End===
:"Thanks. Except I used to belong to a much better club. And now I'm powerless. I'm hapless, I'm hopeless. I mean, why the hell not bury myself in women and decadence, right? It's the end, baby. That's what decadence is for. Why not bang a few gongs before the lights go out? But then that's, that's just how I roll."
Castiel phones Dean, eager to meet up and search for the Colt, but Dean begs that he wait until morning. Castiel agrees and continues standing, rather forlornly, on the side of a highway.
Dean wakes in the morning to find that Zachariah has zapped him five years into the future, into 2014. In appears that in 2012, Lucifer's minions re-released the Croatoan demon virus. In this post-apocalyptic world, most humans have been reduced to murderous zombies. Dean goes in search of Bobby, and finds a photo showing that Castiel is at Camp Chitaqua. When Dean arrives, he finds that Future Dean, Future Chuck and other survivors are also there.
Future Castiel informs Dean that sometime after the Croatoan virus was released, the angels left, and so did most of his angelic powers, so that Cas is now effectively human. He can however detect that Dean from 2009 is different from Future Dean. He is embittered at his situation and has immersed himself in "women and decadence". When Dean first encounters him, he is organizing an orgy, and when Dean asks if he is stoned, he says "Generally - yeah."
Future Castiel is presumably killed during the attack Dean leads on Lucifer.
When Zachariah brings Dean back to the present, he once again asks him to be Michael's vessel. When Dean refuses, Zachariah is about to take him prisoner and torture him again, but Castiel intervenes, transporting Dean to safety at the roadside where Cas has been waiting. Dean comments on his good timing, and Castiel smiles, saying "we had an appointment". Dean tells him not to ever change and later calls Sam to bring him back.
===5.06 I Believe The Children Are Our Future===
:"With Lucifer risen, this child grows strong. Soon, he will do more than just make a few toys come to life—something that will draw the demons to him. The demons will find this child. Lucifer will twist this boy to his purpose. And then, with a word, this child will destroy the Host of Heaven."
Sam and Dean ask Castiel for help when they discover that Jesse Turner is a cambion, the son of Julia Wright and a demon. Castiel insists that Jesse must be killed as he is incredibly powerful, even capable of "killing the Host of Heaven with one word." Because he can transport himself anywhere Jesse cannot be held prisoner, and though Jesse is not himself evil, Castiel is unwilling to take the risk that Jesse would choose to serve Lucifer. However, when he attempts to kill the boy, Jesse turns Castiel into a small action figure. Castiel is restored when Jesse leaves and goes into hiding.
===5.08 Changing Channels===
:"Hello, Gabriel."
When the Trickster traps Sam and Dean in an unending series of TV shows, Castiel tries to rescue them but is banished. When he reappears, Castiel is bloodied and bruised, and says he thinks it may be something more powerful than the Trickster - who appears and again banishes him. 
Finally, after the Trickster is revealed to be Gabriel, Dean gets him to bring Castiel back.
===5.10 Abandon All Hope...===
:"Bobby's right. Tomorrow we hunt the devil. This is our last night on earth."
Castiel discovers the crossroads demon Crowley making a deal with a banker. He follows the demon to the house Crowley is occupying, and informs Dean of its location by phone, then reveals that the house is protected from angels by Enochian symbols. Sam and Dean recruit Ellen and Jo to help with the mission, and the four of them breach the house. Sam and Dean find Crowley and are shocked when he willingly hands over the Colt and the location of Lucifer.
The team regroups at Bobby's, and Castiel does shots with Ellen and Jo (after the latest 5 he declares that he's "starting to feel something"). The hunters prepare to take on Lucifer in Carthage, Missouri, and Bobby insists on taking a photo of them all so he has something to remember them by. The others laugh off Bobby's comment, but Castiel observes that "Tomorrow we hunt the Devil. This is our last night on earth."
When the team arrives in Missouri, Castiel sees reapers everywhere. He follows one, trying to find out why they are there and is captured by Lucifer, who imprisons Cas in a ring of flaming holy oil. Lucifer describes Castiel as a "peculiar thing," and questions him about his arrival and who he has brought with him. He tries to convince Castiel to join him, because Castiel will be Heaven's target if Lucifer is defeated, but Castiel refuses. Lucifer leaves to finish his ritual, leaving Meg to watch over Castiel. Castiel manages to loosen the fittings on an overhead pipe and uses it to knock Meg into the flaming circle. Castiel tries to cast her out of her host, but finds that without Heaven's support he is unable to do so. Meg mocks him as powerless, and Castiel throws her onto the holy fire, walking over her to escape. He arrives in time to save Sam and Dean from Lucifer.
===5.13 The Song Remains The Same===
:"If you're out of prison, it's because they let you out. And they sent you here to do their dirty work."
Anna comes to Dean in a dream, telling him that she has been held prisoner in heaven after being turned in by Castiel, but has escaped. She wants Dean to meet her, but instead of Dean, Castiel arrives. He does not believe she could have escaped on her own, having himself experienced "Heaven's persuasion". He accuses her of working for Heaven against the Winchesters. Anna denies this, but insists that Sam must die so that Lucifer cannot take him as a vessel. She fails to convince Castiel, who refers to Sam as his friend. He informs her that, despite their shared experiences, if she attempts to harm Sam, he will kill her.
Later, after informing Sam and Dean of the situation, Castiel performs a ritual to determine Anna's location. He discovers that Anna has gone back in time to kill Sam and Dean's parents. Sam and Dean insist that he bring them along, but Castiel protests that time travel is extremely difficult, even with Heaven's support. Because he is outcast, he tells them that "taking this trip, with passengers no less...it'll weaken me". However, he gives in to their continued insistence and packs a satchel containing holy oil and his angel blade, then gives it to Sam. Cas touches the brothers' foreheads, and suddenly they arrive in the year 1978. Sam and Dean find Castiel slumped against a car, bleeding and breathing heavily. He insists that he is better than he expected to be, but then coughs up blood and passes out. Dean books Castiel into the honeymoon suite at a hotel to regain his strength while they fight Anna. Sam is concerned about Cas, but Dean describes him as "tough for a little nerdy dude with wings".
After Sam and Dean are returned to their time by Michael, Castiel appears in their hotel room. He does not immediately realize where he is, but when informed that he has made it back, he admits to being very surprised. He passes out, and the brothers drag him over to a bed to rest.
===5.14 My Bloody Valentine===
:"It's my vessel -- Jimmy. His, uh, appetite for red meat has been touched by Famine's effect."
Sam and Dean investigate cases of people who abruptly kill themselves in odd ways near Valentine's Day. While examining the remains of the victims post-autopsy Sam notices an inscribed angel sigil on two of the hearts. Dean phones Castiel for angelic assistance. Cas appears directly in front of Dean while they are still on the phone. He recognizes the sigils as a mark of union placed on the victims by a Cupid, a lower angel called a Cherub. Castiel, Sam, and Dean go to a couple-filled restaurant, suspecting that Cupid will be drawn to the love-filled environment. While there, Cas asks to eat Dean's untouched hamburger, but before he can take a bite he senses the Cupid has arrived. Castiel traps Cupid in the back room of the restaurant and forces him to show himself.
Cupid manifests as a naked man and goes around giving Dean, Castiel and Sam enthusiastic hugs, lifting them up off the floor. Castiel informs them that this is the Cupid's way of shaking hands, and that no one likes it. The three interrogate the cherub about the strange deaths, and he begins to cry. Castiel tries to comfort him, earning another intense hug. The cherub then asks Cas to read his mind so that they will understand that he was not involved in the deaths. Cas agrees and makes eye contact with the other angel. After a moment he turns away, announcing that Cupid is telling the truth.
Later, Sam fights a demon and takes its briefcase. At their motel, Sam and Dean open the case and release a brilliant light. Castiel appears behind them, holding a paper bag of hamburgers, and explains that the brothers released a soul. As he eats the hamburgers, Castiel announces that Famine is in town and is causing the strange, starved behavior among the victims. Even Cas has been affected through his vessel, Jimmy, who craves red meat. Once strengthened by consuming souls, Famine will be able to march across the lands with authority.
Sam is incapacitated by his craving for demon blood, so Castiel and Dean search for Famine. Cas continues to eat, saying that the hamburgers make him very happy. They locate Famine, but Castiel is distracted by a tray of raw ground beef and Dean is captured. Sam arrives after killing two demons and drinking their blood. With his powers he is able to defeat Famine, but is then locked in Bobby's Panic Room by Dean and Castiel. Castiel tries to reassure Dean that Sam will be okay when the blood is out of his system, but Dean leaves.
===5.16 Dark Side Of The Moon===
:"It’s called the Axis Mundi. It’s a path that runs through Heaven. Different people see it as different things. For you, it’s two-lane asphalt. The road will lead you to the Garden. You’ll find Joshua there. And Joshua… can take us to God."
Sam and Dean are killed, and Dean wakes up inside his Impala. Young Sam is there, and Dean realizes he's reliving a happy memory. When Dean remembers that he and Sam were shot, the memory disappears, and Dean hears Castiel's voice coming from the Impala's radio. Castiel tells Dean that he is dead and is in Heaven. He urges a confused Dean that he must follow the asphalt road in front of him if he is to find Sam. The connection between Castiel and the radio, made possible by a spell, fades, and Dean is on his own again.
Dean and Sam are reunited in a Thanksgiving memory of Sam's that takes place in an old girlfriend's house. Suddenly a bright light streams through the windows and shakes the ground, forcing Sam and Dean to hide behind furniture in the living room. When the light has passed, a TV turns on. Castiel's face appears on screen, and though the message is grainy and full of static, they can communicate. Castiel warns them "Don't go into the light," revealing that the light is actually Zachariah searching for them. Zachariah's goal is to send Sam and Dean back to Earth and convince them to say 'yes' to Lucifer and Michael. Castiel sends them on a mission to find an angel named Joshua, who resides in the center of Heaven, in Heaven's Garden. Joshua, according to Castiel, is rumored to be the angel that God speaks to, and their only chance of finding God on Earth. To find him, the brothers must follow the Road, the axis mundi, for it will lead them to Heaven's Garden. The Road weaves through Sam and Dean's memories, and they become lost and are eventually captured by Zachariah.
Joshua interrupts Zachariah with a message for Sam and Dean. He informs them that though God was the one who saved them from Lucifer and resurrected Castiel, God will not intervene to destroy Lucifer and stop the Apocalypse. Sam and Dean are returned to Earth with the knowledge that their last resort has failed. The brothers relay the devastating news to Castiel.
At first, unwilling to believe, Castiel suggests that maybe Joshua was lying. Sam regretfully assures Castiel that he believes Joshua was honest. Slowly walking towards the door, his faith broken, Castiel stops and looks up, murmuring,
"You son-of-a-bitch...I believed in..."
He pauses a moment before turning to Dean and returning his amulet, saying, "It's worthless," before disappearing.
And as Sam tries to console Dean, insisting that they will find a way to stop Lucifer. Dean pauses a moment as he leaves the room to throw the amulet away.
===5.17 99 Problems===
:"Fake. It actually means, 'you, um, breed with the mouth of a goat.' It’s funnier in Enochian."
After being called by Sam, Castiel turns up in the brothers motel room. As he staggers forward, Sam asks if Cas is drunk. He denies this initially, then admits that he found a liquor store, then drank it. Sam asks if he is alright, and Cas motions for him to lean down and mutters "Don't ask stupid questions". When asked about the local prophet, Castiel reveals that the names of all the prophets are "seared" into his mind, and that her name is not among them. He helps the boys determine that they are dealing with the Whore of Babylon and supplies them with a stake of cypress from Babylon with which to kill her. He also informs them that only a "true servant of Heaven" can kill the Whore, and that neither he, Dean, or Sam qualifies. Castiel finds the town pastor and brings him to the brothers, who explain the situation. The pastor is shocked, and wonders why an angel like Castiel could not kill the creature. Castiel responds that he is a poor example of an angel.
Outside the motel, Castiel sits on a bench and leans forward, rubbing his forehead. Dean tosses him a large bottle of aspirin, and suggests that he take them all. They talk briefly about absent fathers. Later, Castiel is injured when the Whore of Babylon attacks him.
===5.18 Point Of No Return===
:"I rebelled for this?! So that you could surrender to them?"
As Dean prepares to say yes to Michael, Castiel and Sam appear and take Dean back to Bobby's. As they argue over alternatives, Castiel is struck with a sudden pain. When asked if he's okay, Cas replies that "something’s happening" and vanishes. He arrives in a wooded area where the trees have been flattened by angelic power - the angels have resurrected someone. The ground in the center of the fallen trees pulsates and Castiel tries to help the resurrected man out of his grave. As he leans forward, an angel attacks him from behind. They fight, and another angel appears. Castiel manages to kill his assailants, and turns back to the figure struggling out of the ground. Cas pulls him out and transports him Bobby's. The others gather round, and it is revealed that the Winchesters half-brother, Adam Milligan, is the man. Castiel shields Adam with a set of Enochian sigils. The Winchesters talk with Adam, who claims that he is supposed to act as Michael's vessel. Castiel suggests that the angels have decided that Dean will not say yes, and so are turning to Adam as a back-up as he is also John Winchester's son.
While Sam, Bobby, and Castiel try to plan their course of action, they keep an eye on Adam and lock Dean in the panic room. When Castiel goes to check on him, Dean tricks him into entering the room then puts his hand to a hidden Angel Banishing Sigil, sending Castiel away and giving Dean time to escape.
Once in town, Dean approaches a street preacher and asks him to call the angels so that he can assent to Michael. Castiel appears and touches the preacher, causing him to pass out. Castiel attacks Dean, beating him severely and raging that Dean is prepared to surrender after all the sacrifices the angel has made to help the Winchesters avoid the Apocalyptic battle between Michael and Lucifer. Lying on the ground, Dean encourages Castiel to kill him, but Castiel relents and taps Dean on the shoulder, knocking him out. Cas then takes him back to Bobby's, where it is discovered that the angels have taken Adam.
Castiel determines that Adam is being held in the Green Room, and that it is heavily guarded. Castiel takes Sam and Dean to an abandoned warehouse where he says they can access the Green Room. Castiel says he can get them in there, but must fight five angels to do so. Dean suggests that the idea is suicidal. Cas agrees that it may be, but says that is preferable to watching Dean fail, and that he doesn't have the faith in Dean that Sam does. He then removes his tie and takes a box cutter from his pocket.
Inside the dark warehouse, Castiel is attacked by an angel, but defeats and kills him. Four other angels appear, and Castiel drops his blade and yells at them to attack. As they close in on him, he rips open his shirt, revealing that he has carved an Angel Banishing Sigil into his chest. As he slaps his hand to it, it releases a bright flash and sends away all the angels, including himself.
===5.21 Two Minutes To Midnight===
:"Apparently, after Van Nuys, I suddenly appeared, bloody and unconscious, on a shrimping boat off Delacroix. I'm told it upset the sailors."
Dean receives a sudden phone call from Castiel, who disappeared at the end of 5.18 Point of No Return and has not been heard from since. Cas informs Dean that he woke up in a hospital, much to the surprise of the doctors treating him, who thought he was brain-dead. He says that he was found on a shrimping boat off Delacroix sometime after banishing himself and the other angels. Dean tells him that he is with Sam and Bobby, and that Cas should transport himself there. Castiel replies that he cannot teleport because his "batteries are drained"; he is effectively a human. He asks for money for transportation and for "more pain medication, ideally," and Dean agrees to have Bobby send it. Before hanging up, Cas apologizes to Dean for losing faith in him and believing he would turn himself over to Michael.
Dean and Sam meanwhile go after Pestilence, who is using a nursing home as a base of operations. As they approach the room where Pestilence is located, they become stricken by a variety of diseases. When they find the room they need, they are unable to do more than collapse on the floor in front of Pestilence. At this moment Castiel shows up to help, having taken a bus to this location. He enters the room and is immediately struck down by Pestilence, who eyes him with curiosity. He refers to Castiel as an "occupied vessel...but powerless." He speculates that Castiel has no spark of angel left in him, but Castiel mutters maybe a little, grabs the knife dropped by Dean and lunges at Pestilence, managing to sever his ring finger. Cas, along with Sam and Dean, is healed, and he kills a demon that was accompanying Pestilence. The Horseman vanishes, saying that they are already too late.
Later, Castiel accompanies Sam and Bobby in an attempt to destroy a building containing the Croatoan virus, which is disguised as a swine flu vaccine. On the way, Castiel is filled in on Sam's idea to say yes to Lucifer as a means of getting him back into his cage. Unlike Dean and Bobby, Castiel does not dismiss the option, saying that it may be possible and that Sam and Dean have often exceeded his expectations in the past. He also tells Sam that Lucifer's vessel would need to be strengthened by demon blood. Castiel also informs Sam that Michael is now likely using Adam Milligan for a vessel.
At the vaccine shipping facility, Castiel saves Sam from an infected human, using a shotgun for the first time and pronouncing it effective.
===5.22 Swan Song===
:"Hey, ass-butt!"
Sam, Dean, Bobby, and the now quasi-human Castiel have committed to the plan to trap Lucifer and return him to his cage by allowing him to enter Sam. In preparation, they drain a group of demons and bottle their blood for Sam to consume. Next, the four of them travel to Detroit.
In Detroit, Sam says his goodbyes. He asks Castiel to look after Dean and Bobby. Cas states that the request is impossible, but then realizes that he is "supposed to lie." Sam and Dean go to confront Lucifer, and Sam says "Yes." Lucifer enters him and takes hold, and Sam cannot force him into the Cage. Lucifer departs, leaving Dean to return to Castiel and Bobby. Dean asks for suggestions on what to do next, and Castiel suggests they get drunk while they wait for the end. Dean refuses to give up, however, and contacts the prophet Chuck Shurley, who gives him the location of the impending battle between Lucifer and Michael. Dean heads for the location, Stull Cemetery near Lawrence, Kansas. He interrupts the two angels before the fight, insisting on a conversation with Sam, which angers Michael. Suddenly Castiel yells at Michael to get his attention, then hurls a Molotov cocktail full of holy oil at the archangel. Michael is engulfed in flames and vanishes. Cas tells Dean that he will return, but that Dean will have time to talk to Sam.
Outraged by Castiel's audacity in attacking Michael, Lucifer obliterates him with a snap of his fingers, then kills Bobby moments later. After Dean and Sam succeed, and Lucifer (as well as Sam) and Michael are imprisoned, Castiel returns. An astonished Dean asks the angel if he is God, and Cas says no, but he believes God brought him back. Cas' angelic nature has been restored, and his powers improved. Castiel heals Dean of his injuries and brings Bobby back to life.
Castiel leaves the cemetery with Dean, riding in the Impala. Dean asks Castiel about his plans. Castiel says that Heaven must be in chaos without Michael, and that he will return to help restore order. Dean is critical of Castiel's willingness to return to Heaven in the service of God after all they have been through. Castiel believes that God likely helped them more than they suspect. Before he leaves, Cas suggests that Dean even got what he asked for: "No Paradise. No Hell. Just more of the same. I mean it Dean. What would you rather have? Peace - or freedom?"
===6.01 Exile On Main St.===
Sam tells Dean that after he came back from Lucifer's Cage, he prayed to Castiel in hopes that he could explain what happened. Castiel didn't answer, and he does not appear in this episode.
===6.03 The Third Man===
:"Sam, Dean, my 'people skills' are 'rusty.' Pardon me, but I have spent the last 'year' as a multidimensional wavelength of celestial intent. But believe me, you do not want that weapon down here. Help me find it. Or more people will die."
Following a string of deaths that resemble three of the twelve plagues of Egypt, Dean prays to Castiel in the hope that he will be able to answer some of their questions. Sam is certain that the angel will not appear, because Sam has prayed to Castiel several times since he escaped Lucifer's Cage a year ago without receiving an answer. Castiel appears behind Sam, and greets the brothers, much to Sam's chagrin. 
might have responded but I don’t know. Sam, we have no idea who brought you back from the cage or why.
Castiel then goes on to explain that he came, not because Dean called him, but because the recent deaths have been caused by a powerful angelic weapon known as the Staff of Moses. He tells them that Heaven has been in chaos following the Apocalypse and the loss of Michael, and several of Heaven's weapons have been stolen. He asks the Winchesters for their help in finding the Staff. Together, the three of them visit the family of a boy who was murdered and then framed by the recent plague victims. They soon discover that the boy's brother, Aaron Birch, has a piece of the Staff. Castiel takes the Staff fragment from him and Aaron explains that he sold his soul to an angel in exchange for the weapon. Castiel insists that they must find the angel and the other pieces of the Staff.
Castiel teleports Sam, Dean, and an unconscious Aaron back to the brothers' motel room. He reveals that he can read the unknown angel's mark within the boy, but notes that it will be excruciatingly painful for Aaron. Dean objects, but Sam agrees that it is necessary. Castiel proceeds, and discovers the angel is Balthazar, a close friend of his who was believed to have died during the war. Before Castiel can make sense of Balthazar's actions, an angel appears and attacks him. The two fight and fall out a window, landing on Sam's car, crushing it. Castiel recovers and the second angel departs. Castiel explains that the other angel is a servant of Raphael, who is free and has gathered a following of traditionalists who wish to restart the Apocalypse. Sam surmises that the angels are in a state of civil war; Castiel admits that this is the case, and that he is ashamed of his brothers' actions. He then conducts a spell to locate Balthazar, and transports the three of them to his location.
Castiel ventures into Balthazar's suite alone and confronts him about his conduct. Balthazar explains that he is simply following in Castiel's footsteps by making his own decisions and doing whatever he likes. Castiel demands he return the stolen weapons, but Balthazar declines. They hear an indication of Raphael's arrival, and Balthazar disappears. A hostile angel attacks Castiel, who pleads for him to stand down, but is forced to kill the other angel. Raphael appears and beats Castiel mercilessly, throwing him down a flight of stairs. Just as Raphael is about to kill Castiel, Balthazar reappears and destroys Raphael's vessel using Lot's Salt. He remarks that Raphael will be too preoccupied looking for a new vessel to pose a threat anytime soon.
Before Balthazar can leave, Dean lights a hidden ring of holy oil, trapping the angel. Dean demands the return of Aaron's soul. Balthazar is furious, but agrees when Castiel refuses to interfere. After he releases the soul, Castiel frees Balthazar before Dean can demand anything else, declaring that his debt to the second angel is cleared. Balthazar and Castiel vanish.
===6.06 You Can't Handle The Truth===
:"I'm at war. Certain... regrettable things are now required of me."
When Dean discovers that an antique horn was recently stolen from a local music store, he theorizes that it is an angelic weapon, Gabriel's Horn of Truth, and is causing the disruption in Calumet City. He prays to Castiel, who appears immediately when Dean mentions the possibility of a holy weapon being in town. Dean is angry with him for only answering when it's in Castiel's own interest to do so, because Dean has been calling Cas for help with Sam. Dean is afraid that Sam may still be possessed by Lucifer, but Castiel tells him that the angels would feel it if Lucifer were free. He picks up a bottle and pours Dean another drink. Castiel once again tells Dean that he doesn't know what's going on with Sam, and reminds him that he is fighting a civil war.
Dean starts to explain his theory about the Horn, and Castiel disappears before he can finish. He then reappears two seconds later and announces that the Horn of Truth is not causing the disturbance because it is not in town; he knows because he looked everywhere. Before he goes again, he tells Dean that he does want to help with Sam and that he'll make some inquiries.
===6.07 Family Matters===
:"This is a vessel. My true form is approximately the size of your Chrysler building."
Dean calls Castiel for help immediately following the events of 6.06 You Can't Handle the Truth. Sam is tied to a chair and still bloody from Dean's pummeling. Castiel takes the opportunity to ask Sam a few questions. He quickly discovers that Sam is no longer sleeping or feeling any emotions, which worries him, so Castiel performs a ritual similar to the one he used prior on Aaron Birch. He reaches inside Sam's abdomen with his angelic powers, and, as it is an extremely painful experience, he has Sam bite down on his belt. What Castiel learns from the examination is that Sam's soul is missing and is likely still in Lucifer's Cage. With no other clues, they decide to head to the Campbell Compound and question Samuel Campbell, who came back from the dead at the same time that Sam escaped Lucifer's cage. Before they leave, Dean has Castiel heal Sam's earlier injuries.
At the compound, Dean questions Samuel about his resurrection, but Samuel reiterates that he doesn't remember anything before waking up alive. Dean insists that Samuel talk to their 'wingman,' and Castiel appears beside Samuel.
Castiel tests Samuel to see if he still has a soul - he does - and Castiel leaves shortly afterward. Before goes, though, he promises Dean that he will be on the lookout for something to help Sam regain his soul.
===6.10 Caged Heat===
:"If the pizza man truly loves this babysitter, why does he keep slapping her rear? Perhaps she’s done something wrong."
Sam prays to Castiel, and when the angel does not answer, claims that he has found the lost Ark of the Covenant. Fooled, Castiel appears to Sam and asks where it is, but is met with hostility and derision because he is unaware that Sam was referencing Raiders of the Lost Ark. Sam demands that he help them track down Crowley. Castiel informs Sam that he is in the middle of a battle but Sam doesn't care and threatens to kill Castiel if he does not help him. Castiel simply replies "You need help," but agrees to assist nonetheless by performing a spell to locate Crowley. The spell fails because Crowley is shielded. Castiel then accompanies Sam and Dean to Samuel's office in the Campbell Compound, but is asked to leave when Samuel catches them so that the family may discuss matters in private. He is later seen watching a porno and struggling to understand it while Sam and Dean do research at their hideout.
Samuel comes around and tells them where they can find the demonic prison housing the monsters, though he refuses to take part in the attempt on Crowley. Outside, they meet with Meg and three of her demon cohorts. Castiel is displeased with the notion of working with an "abomination," Meg in particular. There is a confrontation in which Sam kills one of Meg's associates, but they agree to proceed together. Alone with Dean, who is preparing for the mission, Castiel suggests that forcing Sam's soul back into his body could have catastrophic consequences for him, as Lucifer and Michael will no doubt have spent the last year tormenting him. Dean is convinced that restoring his brother is the right thing to do, however. The group infiltrates Crowley's base, a disused prison protected by demons, hellhounds, and spellwork.
Inside they are attacked by hellhounds, losing the other two demons following Meg before blocking the dogs behind a locked door and a line of salt. Deciding that she would have the best chance of holding them off, Meg tells the brothers and Castiel to find and kill Crowley. Suddenly, she kisses Castiel passionately while reaching inside his coat. To everyone's surprise, Castiel reciprocates, apparently inspired by the porno he saw earlier. When they pull away from each other, Meg is holding his Angel Blade. Castiel does not object, and leaves with the brothers while Meg uses the weapon to fight the hellhounds. Castiel is not with them for long, however, as Samuel banishes him with a blood sigil.
In his absence, the Winchesters and Meg eventually manage to catch Crowley in a devil's trap, but he escapes and overpowers them all. Castiel reappears suddenly, holding a burlap bag that contains Crowley's bones. He demands to know if Crowley can genuinely retrieve Sam's soul from the cage, and the demon admits that he cannot. Castiel burns Crowley's bones with a wave of his hand, and the demon is destroyed.
At Dean's request, Castiel agrees to dispose of the remaining monsters within the prison. He then disappears after admitting that he is on the losing side of the war against the archangel Raphael and that he would prefer to be on Earth with Sam and Dean.
===6.12 Like a Virgin===
:"Let me tell you what his soul felt like when I touched it. Like it had been skinned alive, Dean. If you wanted to kill your brother, you should have done it outright."
Sam is still unconscious over a week after Death returns his soul. Dean calls Castiel, who reads Sam's soul in the panic room. He confirms that the soul is there, but when Dean asks if Sam will ever wake up, Castiel is doubtful. He says that Sam's soul feels "skinned", and he is critical of Dean's decision to have it returned. He even tells Dean that if he wanted to kill his brother, there were other ways.
After Sam awakens, he has no memories of the past year. Dean is not willing to tell him the truth, but Sam begins to suspect that something happened during the missing year. He prays to Castiel while Dean is away. Cas appears, and rejoices to see Sam awake and alright. He even tries to hug Sam, but when Sam hesitates, Cas realizes that a hug would be awkward. The angel tells Sam that what has happened is nothing less than a miracle, and admits that he was against Dean's choice. He asks Sam how it feels, and when Sam asks what he means, Castiel reveals that Sam's soul has been put back. Sam realizes that he must have been on Earth without his soul, but hides his surprise from Castiel. Sam then says that he is a little confused about some things, and asks Castiel to talk with him about some of the things that have happened during the last year and a half. Castiel does so.
===6.15 The French Mistake===
:"When will I be able to make you understand? If I lose against Raphael, we all lose. Everything."
Balthazar appears to Sam and Dean, telling them that Raphael is trying to kill all of Castiel's allies in one night, and that "Cassie" is underground. He gives them a key to the angelic weapons he stole, then conducts a ritual. Sam and Dean are thrown into an alternative universe in which they are actors named Jensen Ackles and Jared Padalecki on a show called "Supernatural". On the television backlot, Dean prays to Castiel for help. Spotting what appears to be Cas a moment later, they rush over to talk about what has happened, only to find that it is not Castiel, but Misha, the actor that plays him on the show.
The brothers are eventually pulled back into their universe by Raphael, who was trying to bring back his assassin Virgil. Balthazar arrives, and reveals that the key he gave them is fake, and he was playing for time to move the weapons. Raphael threatens the Winchesters, but Castiel arrives. The shadows of his wings flicker on the building behind him as he tells Raphael that the "power of the weapons" is with him, and that he will kill the archangel if he remains. Raphael vanishes. Balthazar also leaves after a parting word to Castiel.
Castiel goes to the brothers and touches their shoulders, transporting them and himself to Bobby's house. Dean demands to know if Castiel was involved in Balthazar's plot to use them as decoys. Castiel says that he was not, but that if necessary he would also have used them as a distraction. Dean is angry, but Castiel reminds him again that if his side loses to Raphael, everyone loses. The brothers want Castiel to tell them about what is really going on in the war. He says that he will when he can. Then he disappears.
===6.17 My Heart Will Go On===
:"Well, yeah. You're the ones who taught me that you can make your own destiny. You don't have to be ruled by fate. You can choose freedom. I still believe that that's something worth fighting for. I just wanted you to understand that."
After Balthazar prevents the Titanic from sinking, Sam and Dean approach Atropos, one of the Fates, who is killing off the descendants of the survivors that should have died. She sets a trap for them, but they are saved at the last instant by Castiel, who transports them to Russia. He thinks that they are foolish to have tried to speak with Atropos, who is furious with them for having averted the Apocalypse and making her obsolete. He knows Atropos, and suggests that the only way to save them and the Titanic survivor descendants is to kill her, when she next tries to strike Sam and Dean.
When she does attack the brothers, and time freezes, Castiel appears. He tells Atropos that her services are no longer required, and that freedom is the better way. She is furious with him over his role in the Apocalypse and even more so over what Balthazar has done to history. Castiel suggests that Balthazar acted on his own whim, but Atropos accuses Castiel of having given the order to 'unsink' the ship. She says that Balthazar follows him, and that they were intent on creating new souls for the war in Heaven. Castiel answers her accusations evasively.
Atropos blackmails him with the lives of his "pets" - Sam and Dean. She will kill them if he does not restore the natural order, and if he kills her, her sisters will take care of the brothers. She knows that Castiel will not always be able to guard them because of the war. Castiel orders Balthazar, who has snuck up behind Atropos with a knife, to stop. He agrees that they will go back and sink the ship - again.
When Sam and Dean wake in the restored universe, they remember the alternate one as a dream. Castiel tells them it was not a dream, and he wanted them to remember their encounter with Fate. She is capricious, and he still believes that free will is worth fighting for. Dean asks if Balthazar really tried to change history because of a movie. Castiel hesitates and looks away, then says yes, that was the reason.
===6.18 Frontierland===
:"Doing this is like... putting your hand in a nuclear reactor. I have to do it very gingerly... Or you'll explode."
Dean prays to Castiel for his assistance in time traveling. He is surprised when Rachel appears instead. She says she is Castiel's friend and that he is busy with his troops, then berates Sam and Dean for calling Castiel only when they need something from him. Castiel arrives and dismisses Rachel, who is his lieutenant, saying he will handle the matter himself.
He agrees to send the brothers back to 1860 so that they can find Samuel Colt and the ashes of a Phoenix, but warns them they have only twenty-four hours. If they stay longer he cannot retrieve them. After the brothers are gone, Castiel tells Bobby to pray for him as the deadline approaches, and he will return.
Later, Castiel meets Rachel in a warehouse. She demands to know if his "dirty little secret" is true. Castiel replies that he is fighting a war. Rachel attacks him with an angel blade, stabbing him in the abdomen. Castiel fights her off and pulls his own blade. They struggle, and Castiel kills her; he murmurs "I'm sorry." Still injured, he retreats to Bobby's place and draws a sigil in blood on Bobby's refrigerator door to ward off other angels. Bobby tries to help him, and Castiel passes out.
When he awakens on Bobby's sofa, it is nearly time to bring back Sam and Dean. Castiel tells Bobby that Rachel turned on him, corrupted by Raphael. When Bobby asks him about the Winchesters, Castiel says that he is too weak to pull them back on his own. Bobby asks what they can do, and Castiel replies that the only option would be for him to touch Bobby's soul, and tap its energy. If he does it incorrectly, Bobby will explode. Bobby agrees for Sam and Dean's sake. Castiel reaches into Bobby's chest, and after a few moments Sam and Dean return.
They did not get the ashes, and ask Castiel to send them back, but he lacks the strength, and says he never wants to do that again. Fortunately, Samuel Colt gathered the ashes and arranged for their future delivery.
===6.19 Mommy Dearest===
:"Right. Pardon me for highlighting their crippling and dangerous empathetic response with 'sarcasm.' It was a bad idea letting them go."
Bobby, Sam, and Dean need to find Eve, and intend to ask Castiel's assistance. Before Dean can call on him, Castiel appears to ask about their progress. He cannot locate Eve himself, so Sam suggests that they try to find one of the few helpful monsters they have encountered over the years. Castiel finds Lenore, and brings her to Sam and Dean. She reluctantly gives up Eve's location, then asks to be killed because she can no longer resist the urge to feed. The brothers are hesitant and try to persuade her to wait until after Eve's death, but Castiel appears behind her, places a hand on her head, and incinerates her.
Castiel transports Sam, Dean, Bobby, and himself to the city in which Eve is hiding. At the local diner, he discovers that his powers are being blocked by some outside force. Irritated, Dean calls him a "baby in a trench coat" without powers, and Castiel seems hurt by the comment. They pair off to search the town. Cas and Dean look for the local doctor, who reported a strange illness, but find the body of the infected patient instead. They regroup at the residence of the infectee, but Castiel soon observes that there is another person inside who looks exactly like the victim. Inside are more dead copies of the man. Before dying, one of the copies reveals that they had encountered a strange woman at a bar.
The four go to the bar to investigate and find dozens of bodies, some of them new monsters. They are interrupted when police officers burst inside. Dean hides, but Cas, Sam, and Bobby are arrested. At the station, they discover the officers are monsters. Dean attacks by surprise and between the four of them they manage to kill all but one, which they take prisoner. Cas watches while Bobby interrogates the monster. Sam and Dean find two boys tied up in a cell, and decide to take them to their uncle's house. Castiel argues that they have bigger concerns, and that the brothers should remain, but they decide to leave nonetheless.
Bobby continues the interrogation, until Castiel asks him to leave the room for five minutes. Outside, Bobby hears screaming. Castiel emerges with Eve's location, and wipes his bloody hands on a towel.
Eve is at the town diner. Sam and Dean go inside while Bobby and Cas wait as back-up. In the diner, Eve tells the brothers that Crowley remains alive and killing, and offers to let them live if they will bring him to her. Her monsters capture Cas and Bobby and bring them into the diner. Dean refuses to give in, telling Eve to "bite" him. She takes him at his word, biting his neck and drinking his blood. She is poisoned because Dean ingested phoenix ash. Her death releases Castiel. He orders the humans to shield their eyes, then raises his hands and emits a blinding flash that kills the monsters. He heals Dean, then takes them in pursuit of the two boys they 'rescued' because they are monsters.
The boys have been killed by demons. Sam and Dean reveal what Eve said about Crowley, and Cas says he will investigate. After he is gone, Sam and Bobby express their doubts about how Crowley could be alive if Cas were not somehow involved.
At the diner, Castiel looks at the bodies. Crowley approaches him, saying he is tired of cleaning up Castiel's messes.
===6.20 The Man Who Would Be King===
:"So, that's everything. I believe it's what you would call a... tragedy from the human perspective. But maybe the human perspective is... limited. I don't know. That's why I'm asking you, Father. One last time. Am I doing the right thing? Am I on the right path? You have to tell me. You have to give me... a sign. Give me a sign. Because if you don't... I'm gonna ju-- I'm gonna do whatever I... Whatever I must."
Sitting in his favorite Heaven, the Tuesday afternoon of an autistic man who drowned in a bathtub, Castiel prays, and tells his story. He remembers a time before humanity, watching a special little fish by the seashore. He remembers the Tower of Babel, David and Goliath, and Sodom and Gomorrah. But to him, the most important event in all of history was when Sam, Dean, Bobby, and Castiel himself stopped the Apocalypse. It was a moment when he made the choice to stand up for himself and his friends, had died for it, and been brought back by God. Castiel decided to go to Hell again, this time to save Sam. He returned him to Earth, and was proud of having done so, but not all of Sam came back.
When he returned to Heaven, and told the other angels that God had given the freedom and free-will, they were confused and frightened. They did not know what to do. A few weeks passed, and Raphael summons Castiel to an audience. He orders Cas to swear loyalty to him or die, and that they will then free Michael and Lucifer. Castiel insists that the battle should not happen, and that he will not let Raphael free them. Raphael assaults Castiel in a show of power, leaving him bleeding on the ground, and reminding him that tomorrow he will swear to obey.
Castiel goes to Dean, and watches invisibly as he rakes leaves. Castiel needs help, but thinks that after all Dean has sacrificed it would be wrong to ask for more. As he continues to watch, Crowley appears beside him. He asks to speak with the angel about the situation, and hints at a possible deal. Castiel rebuffs him, saying he has no soul to sell. Crowley persists, and Castiel, believing himself to be safe from the demon's machinations because he is, after all, an angel, goes along. He later admits that he may have been a fool to do so.
Crowley takes Castiel to the remade Hell he rules, where instead of being tortured, everyone stands in line eternally. Crowley knows the situation with Raphael, and Castiel is prepared to given in rather than die. Crowley suggests that God brought Castiel back for a reason, and that reason was most likely to prevent just this. He should fight back. Castiel is hesitant to start a civil war, especially as he lacks the power to fight Raphael. Crowley has an idea for tapping the untouched well of souls in Purgatory. They could split the souls they find there, so that Castiel can do what God must have intended, and Crowley can strengthen his own tenuous position; he feels he is a better ruler for Hell than most, especially where Castiel is concerned. Castiel hesitates, saying that Crowley's plan would take months, and he has only a day. Crowley tempts him with one more offer: 50,000 souls from Hell to use in facing Raphael. Castiel agrees, and admits to being "prideful" when he banished Raphael the next day, and started the war.
He has been working with Crowley ever since, and the Winchesters are suspicious. Castiel still thinks of himself as their protectors. After Eve's death Crowley and Castiel discuss matters over her body. Crowley is angry that she was killed, as there is little she can do to open Purgatory for them as a corpse. He yells at Castiel for putting his "pets" first, and thinks they should just be killed to simplify matters. Castiel refuses, and threatens Crowley if he dares to hurt them.
Castiel, unseen, watches the Winchesters and Bobby as they hunt Crowley through his minions. They also discuss whether or not Cas is "Superman who's gone darkside". They find out about a demon named Ellsworth who will know Crowley's location, and head out, but Castiel gets there first, killing the demons and getting rid of the evidence. He does not know if he did it to protect the brothers or himself. He watches in hiding as his friends puzzle over the empty house, and does not answer when they pray to him. Three of Crowley's demons attack, and Castiel shows himself, killing them. He admits to Sam, Dean, and Bobby, that Crowley is alive, and he is not sure how he could have been tricked. Their fears are eased, and they say that they had suspected Castiel. Castiel says it would be ridiculous for him to work with Crowley, for "Superman" to go evil. He does not realize his error. Castiel addresses Crowley again, making his point about the Winchesters' safety more strongly.
Later Sam, Dean, and Bobby summon him, and trap him in a ring of holy fire. Dean asks him directly if he has been working with Crowley, and Castiel cannot bring himself to lie. They are angry with him. Castiel tries to defend his actions, saying he has done this for them, and that he rescued Sam. Sam is not consoled, and reminds him he did a poor job. Dean tells him that working with a demon is wrong no matter what, and that he should have come to them. Castiel knows that he could have benefited from Dean's advice back then. A cloud of demons approaches and Castiel tells them to run. They do, and Crowley appears to Cas. He did not harm the Winchesters, and he frees Castiel. He tries to remind Castiel of their goals, but Castiel is angry and does not want to be in his presence. Crowley accuses him of not recognizing what he has become.
Castiel comes to Dean at Bobby's house. Dean says once again that it is a bad idea for Castiel to work with a demon, and asks him to stop. Castiel is like a brother to him, one of the three people he holds most dear. But he will stop him if he must. Castiel thinks there is little Dean, as a human, can do. Dean reminds him that he has had success with stronger adversaries. Nonetheless, Castiel feels compelled to continue fighting his way. Both are sorry to have come to this.
In his favorite Heaven, Castiel finishes his story. He begs God for a sign, for some guidance about whether he is right or wrong. Otherwise, he will do whatever is necessary to win this war.
===6.21 Let It Bleed===
:"Dean, I do everything that you ask. I always come when you call, and I am your friend. Still, despite your lack of faith in me, and now your threats, I just saved you, yet again. Has anyone but your closest kin ever done more for you? All I ask is this one thing."
Castiel has taken one of the Campbell diaries, and is investigating an incident in which H.P. Lovecraft opened a portal to another world. He gets to two sources just ahead of Bobby.
Sam prays for him, telling Cas that Lisa and Ben have been kidnapped by Crowley, and asks for help. Castiel listens unseen, and does not answer, but goes to confront Crowley. He insists that the demon not harm Lisa and Ben, but Crowley refuses to make such a promise. He tells Cas to continue investigating, and the angel receives a summons, then leaves.
Balthazar has called him. He asks Cas if he is working with Crowley; Cas lies that he is not, but Balthazar is not fooled. He is concerned that Castiel will act as the vessel for the souls if he manages to unlock Purgatory, and could explode, destroying part of Earth. Castiel asks if he is with him, or not. Balthazar says he is.
Castiel goes to Dean, arriving just in time to save him from a demon. He apologizes for Lisa and Ben, revealing that he did not know Crowley's plan. Dean is skeptical, and angry. Castiel asks him again to support his decision to tap the souls in Purgatory. He pleads with him that he has always done what the brothers needed him to, asking little in return. Cas asks them to trust in him, and promises to bring him his family afterward. Dean is unwilling, and Castiel leaves.
After Dean and Sam rescue Lisa, Castiel comes to the hospital where the gravely injured Lisa is not expected to survive. He apologizes again, but Dean is not forgiving. Castiel says that he did not a come for Dean, then places a hand on Lisa's forehead, healing her. Both Dean and Cas acknowledge that this does not change their situation, but Dean asks for an additional favor. Castiel removes all Lisa and Ben's memories of Dean.
Later Castiel finds and takes Dr. Visyak, the creature he needs to open Purgatory.
===6.22 The Man Who Knew Too Much===
:"I'm glad you made it, Sam. But the angel blade won't work, because I'm not an angel anymore. I'm your new God. A better one. So you will bow down and profess your love unto me, your Lord. Or I shall destroy you."
Castiel and Crowley torture Dr. Visyak until they obtain what they need to open Purgatory. She escapes and contacts Bobby and the Winchesters, telling her story before dying in an alley. Castiel comes to the three hunters, who are outraged. Dean tries to argue with him again, but Cas cuts him off, saying he no longer cares about Dean's opinion. He then touches Sam's head, breaking the mental wall, and promising to repair him as long as Dean stops the opposition.
Castiel meets with Crowley, who has assembled the necessary ingredients. The angel wants to renegotiate their deal. He will not give Crowley the souls, so Crowley can either flee or die. The demon leaves Castiel with the blood for the ritual.
Later, Castiel confronts Balthazar. He says that Dean is coming, and someone among them is a traitor. Balthazar asks him who it is, and Castiel lies that he does not know, and wants Balthazar to investigate. While the other angel is distracted, Castiel stabs and kills him.
Just before the ritual is meant to begin, a cloud of demons descends around the building, and Crowley appears. Castiel tries to kill him, but cannot. He has a new partner in Raphael. Castiel is surprised at the partnership with their differing goals, but both seem to think they have taken the best course available. They demand the blood; Castiel throws them a jar and leaves.
Crowley conducts the ritual, and though Bobby and Dean try to interrupt, completes it. Nothing happens and Castiel reappears. Crowley realizes that he switched the blood, and conducted his own ritual. Castiel displays his power briefly in a flash of energy. Crowley disappears, and Raphael asks for mercy. Castiel snaps his fingers, obliterating Raphael.
He turns to Dean and Bobby. He was right, he says, and did save them. Dean nervously agrees, then suggests that Castiel should return the souls, and disarm himself. Castiel says he has Raphael's followers to deal with. Dean is worried, and reminds Castiel that he is family, and he doesn't want to lose him. Castiel says that he has no family anymore; he will not give up the souls. Sam stabs him from behind with an angel blade, but nothing happens. Castiel greets him, then says the blade will not work because he is not an angel anymore. He says that he is their new God, and that they must venerate him, or be destroyed.
===7.01 Meet the New Boss===
:"What a brave little ant you are. You know you're powerless, you wouldn't dare move against me again. That would be pointless. So I have no need to kill you. Not now. Besides... once you were my favorite pets before you turned and bit me."
Castiel waits for Sam, Dean, and Bobby to show their respects. Bobby goes to his knees, and motions for Sam and Dean to do the same. Dean begins to kneel, but Castiel stops him, and orders Bobby to stand, saying that there is no point if they do not mean what they do. Castiel observes, without turning to look, that Sam is not doing well. Dean reminds Cas that the former angel promised to fix Sam when it was over. Castiel cuts him off; his promise was contingent on Dean not opposing him further, and oppose him Dean did. Castiel tells them he has no need to kill them, though he no longer has any regard for them, and will let them live if they do not plot against him.
Castiel sets out to right the wrongs he sees. He destroys Raphael's followers in Heaven, and tells the angels that he no longer thinks free will is what Heaven needs. Instead, he will give them a firm hand. He appears in a church, reveals his identity, and smites a hypocritical preacher. He leaves an image of himself in the stained glass as he departs, and accidentally burns a pew as welts appear on his hand. He finds Crowley hiding in a RV, and tells him that he may retain his position as King of Hell, but that Castiel will choose which souls he receives. He leaves after looking at yet more open places on his skin. He gives money to a blind man on the street, and heals the man for his faith. The man is grateful, but surprised when his first sight is of Castiel's blistering face.
Castiel looks at himself in a mirror, growing concerned. He hears a voice inside him calling his name; it wants to come out, it wants him to let it out. It pushes at his skin from the inside. Castiel says no.
Sam, Dean, and Bobby summon Crowley, who reluctantly gives them a spell to bind Death. They work it, and an irritated Death appears, followed shortly by Castiel. Dean orders Death to kill "god." Death says he sees only a mutated angel, one whose vessel is disintegrating. Castiel, sounding uncertain, says he will heal himself when his works are complete. Death replies that Castiel swallowed leviathans when he emptied Purgatory, not just souls, and that is the danger. Castiel frees Death from Dean's binding spell.
Castiel leaves. At a political election office campaigning for a senator of whom Castiel disapproves, he is stopped by one of her aids. Castiel asks the man to see that he is a good god, that he means the best for his children. He awakes some time later in a pool of blood on the floor. He has slaughtered the entire office.
At Bobby's place, Sam prays for Castiel to reconsider and give up the souls. A few minutes later Castiel appears, disheveled, bloody, and looking ill. He says he needs their help.
Back at the laboratory, they work the ritual to open Purgatory. Castiel is growing weaker and weaker, and Dean has to stand him up in front of the portal. As it opens, Castiel turns to Dean and says he is sorry. The souls leave him through the portal, and he collapses.
Dean and Bobby cannot find a pulse, and fear him to be dead. After a moment, Castiel's face heals, and he awakens. Dean and Bobby stand him up. He thanks them for their help, but Dean says they were trying to save the world. Castiel promises to find some way of redeeming himself before Dean. Dean is dismissive, and Castiel insists more firmly. They start to leave, but Castiel doubles over in pain, yelling that something held on inside him and did not leave.
His body is overtaken by the Leviathans, who tells the Winchesters and Bobby that Castiel is not there anymore.
===7.02 Hello, Cruel World===
Dean and Bobby are confronted with one of many Leviathans that is occupying Castiel's vessel; however, Jimmy Novak's body cannot contain them all. It is rapidly deteriorating and so, rather than finish them off, the leviathans retreat. Dean and Bobby follow and find Sam, who is caught up in a hallucination involving Lucifer. Dean snaps Sam out of the hallucination, and the three of them follow the Leviathans, still occupying Castiel's vessel, to a nearby reservoir.
Castiel's vessel wades into the reservoir and, as they watch, disappears beneath the surface. A vortex then erupts outwards and spreads a black ooze throughout the water which vanishes moments later. Bobby remarks that, now that they're in the pipes, the Leviathans will be able to travel anywhere. Dean finds Castiel's trench coat floating in the water, but there is no other sign of the angel's vessel; the hunters assume that he has been destroyed by the Leviathans. Dean takes the trench coat with him as they leave the reservoir. Later Bobby tries to get Dean to talk about how he is coping with Castiel's death, along with everything else, but Dean refuses to talk.
===7.17 The Born-Again Identity===
:"I deserved to die. Now, I can't possibly fix it... So why did I even walk out of that river?"
Dean is trying to find help for Sam, who has been hospitalized due to a psychotic break episode. It has been brought on by his hallucinations of Lucifer, which have plagued him since Castiel bought down the protective barrier in his mind. While searching for help, Dean speaks to a hunter called Mackey. He tells Dean he had heard stories of a healer called Emmanuel. Suspicious, he tracked him down through his wife Daphne Allen in Colorado, and set traps in case the healer turned out to be a monster. When Emmanuel visited him, he was unaffected by the tests, and touched Mackey, restoring the sight in his damaged eye.
Dean travels to Colorado, and finds Daphne being held captive by a demon, which he kills. "Emmanuel" returns home, and to Dean's shock appears to be Castiel, although he gives no sign of recognizing Dean. Emmanuel can see the demon's true face, and is shocked when Dean tells him demons walk the Earth. He agrees to go with Dean, and see if he can help Sam. 
During the drive to the Northern Indiana State Hospital, Emmanuel reveals he has no memories of his life before a few months ago. One day when out hiking, Daphne found him wet and naked by a river, with no memory of who he was. She claimed that God led her to him, and took him home. Using the site bouncingbabynames.com, she helped him choose the name Emmanuel. They later married, and she supports his work as a healer.
When Emmanuel asks about Sam's illness, Dean says that Sam's state is due to something done by a person called "Cas," a name which provokes no response in Emmanuel. He recognizes that Dean feels betrayed by Cas, and asks if Dean killed him. Dean replies that he did not, and reveals that he has not been able to get over what was done. Emmanuel reminds Dean that "you are not a machine," and that his reluctance is reasonable.
Stopping at a market, Dean is attacked by more demons, and unexpectedly saved by Meg. She explains she has been looking for the healer called Emmanuel, as have the other demons. While Dean is suspicious of her, she points out that they are both enemies of Crowley, and she can help protect Castiel. Emmanuel is surprised that Dean would bring a demon with them, but the three of them continue on together.
When they arrive at Northern Indiana State Hospital, it is surrounded by demons. Meg takes Dean aside; she wants to tell Emmanuel who he really is, so he can kill the demons, but Dean warns they don't know how he will react. However, Emmanuel overhears their conversation. Meg tells him he is an angel and that he and Dean used to be friends. "That sounds pleasant" he replies, but Dean counters that it isn't, that angels are violent and corrupt. Emmanuel still doesn't remember anything, but agrees to try and help.
Emmanuel agrees to try killing the demons, and walks down to where they are gathered outside the hospital. As he places a hand to each one's head, killing it, his memories of his time as an angel come flooding back. After he has killed them all, he walks away. Dean goes after him, and Castiel says he has remembered the terrible things he did - all the killing in Heaven and on Earth, and that he is responsible for Sam's condition. He despairs that he can't fix what he did, and should not have survived, but Dean counters that maybe that was why he was brought back. Dean goes to the trunk of his car and takes out Castiel's trench coat, which he has carried with him all this time.
Castiel enters the hospital, and saves Sam from a demon giving him electroshock. Castiel apologies for what he did to Sam, and tries to heal him, but Sam's hallucinations remain. Later, as they visit Sam in his room where he appears worse, Castiel tells Dean that Sam's mind is too damaged and that the mental wall can't be repaired. He then has an idea. He apologizes to Sam a final time before taking all the psychosis from Sam's mind into his own. Castiel immediately starts to hallucinate Lucifer.
Sam and Dean leave Castiel in the hospital, for his own safety. Sam challenges Dean that working with Meg is too much like a demon deal, but Dean says he doesn't think they have much choice. Meanwhile, Meg meets with Dr. Kadinsky and is hired as a nurse so she can, hopefully, watch Castiel.
===7.21 Reading Is Fundamental===
:"Well, you know me. I'm always happy to bleed for the Winchesters."
Castiel awakens in the mental hospital as Sam and Dean uncover the Word. Meg is there, and calls the brothers the next morning to let them know what has happened, saying that Castiel is "different." When the brothers arrive, Castiel attempts to joke with them, and seems unbalanced. Dean in particular is not amused his joke or the random information he spouts. The brothers ask him to look at the tablet they have recovered, and Castiel tells them it was written by Metatron, and that he cannot read it, as it was not meant for angels. Dean and Meg argue, and their confrontation upsets Castiel, who disappears. The Word is dropped, and broken.
Dean finds Castiel in the hospital day room, seated at a table. Dean reproaches him for breaking the tablet, and reminds him of his past wrongs. Castiel holds up the board game Sorry, and invites Dean to play. Dean questions him, but Castiel does not give him the answers he is looking for. Suddenly, Castiel announces that Sam is talking to angels.
He reappears in his hospital room, and sees Hester and Inias, who have come for the prophet Kevin Tran. Castiel greets them, and they are shocked to see him alive. Hester is furious. Castiel tries to come up with something to say to them, but is unable to find the words. Dean, meanwhile, has drawn an angel banishing sigil on the wall outside, and uses it to send all the angels away.
Some time later, while Meg, Kevin, Sam, and Dean are driving, Castiel calls Meg. She has some difficulty understanding him, but realizes eventually that he is at a dog track in Perth, Australia, and gives him the coordinates of their car. Castiel teleports in, terrifying Kevin. They settle at Rufus's Cabin, where Kevin translates.
Meg sneaks out to kill a couple of demons that spotted them at a gas station earlier, and is trapped by Sam and Dean when she returns. They suspect her of treachery. Castiel clears her, but reveals that in killing the demons she alerted the angels to their location. Inias and Hester appear, throwing Meg through a wall. Hester rounds on Castiel, accusing him of having stolen the prophet. She beats him, yelling at him for what he did, especially the introduction of free will. She pulls out her blade to kill him, but is stabbed from behind by Meg.
Inias takes charge of the subordinate angels that accompanied them, and the prophet. He invites Castiel to rejoin them in their garrison, but Castiel declines, saying he is no longer part of it.
Sam and Dean read through Kevin's translation, and discover that as part of the weapon against Leviathans, they need the blood of a fallen angel. Castiel smiles, and holds out a glass vial, saying "I'm always happy to bleed for the Winchesters." They ask him what he will do now, and Cas replies "I don't know. Isn't that amazing?" before he vanishes.
===7.23 Survival Of The Fittest===
:"And at best, I die trying to fix my own stupid mistake. Or... I don't die – I'm brought back again. I see now. It's a punishment resurrection. It's worse every time."
Worried when he can no longer hear the angels' voices, Castiel discovers that his entire garrison has been wiped out, and makes Meg take him to the Winchesters. He approves of the bone they have chosen for the weapon against Leviathans, and then informs them of what happened. Crowley arrives and is shocked to see Castiel, who he believed to be dead. He is confrontational until he realizes Castiel is insane, because there is no fun in fighting a lunatic and agrees to put off their feud until later. Crowley turns his attention to Meg, but Castiel steps forward to defend her and Crowley leaves her be, saying they need Castiel's cooperation to defeat Dick Roman.
Castiel is happy to fetch safe food for the brothers, but refuses to fight, and won't tell Sam and Dean what Crowley meant. After they learn that Dick has had other leviathans take on his form, they again look to Castiel to explain, but he dodges the question and heads off to play Twister. After he leaves, Meg explains that due to his brief stint as the vessel for all the leviathans, Castiel possesses the ability to tell them apart even in their various human disguises, making him the only one able to pick out which Dick is the real one.
After sadly watching Sam and Dean burn Bobby's flask, Castiel takes Dean to the Impala. There, Castiel explains his guilty feelings, that he feels his resurrections are a punishment, and he believes he's bad luck. This doesn't matter to Dean, who would rather have Castiel fighting with him than not. Castiel realizes that Dean forgives him, and Dean admits it, saying he might as well since he will likely die in the fight to come. Castiel finally agrees to join Sam and Dean and promises to do his best before asking what the plan is. Dean tells him they will announce themselves "big."
The next day, while Meg creates a distraction by crashing the Impala into SucroCorp, Sam, Dean and Castiel sneak in. Castiel and Dean search for Dick, and find him in the lab. There, they confront Dick, who taunts Castiel about letting the leviathans onto Earth. When Dick tries to bluff that he isn't the real Dick, Dean points out that Castiel can tell and Castiel attacks Dick, only to be thrown into the wall behind him. After Dean uses a decoy bone to stab Dick, Castiel pulls the Leviathan's head back, allowing Dean to stab Dick through the neck with the real bone, killing him. However, when Dick's soul gets dragged to Purgatory, Castiel and Dean are pulled along with him.
Castiel wakes the unconscious Dean, and after telling him they are more likely to die than get out, disappears.
===8.01 We Need To Talk About Kevin===
When Dean escapes Purgatory with the help of Benny, Castiel is not with him. Dean later tells Sam that Castiel "didn't make it." Dean mentions "something happened to him down there." and that as things got hairy towards the end, Castiel "just let go." Sam asks whether Castiel is dead and Dean saw him die, but Dean only responds "I saw enough." While Dean does not elaborate, this clearly affects him.
In a flashback, Dean is seen searching for Castiel. Later, Benny offers Dean a deal - if Dean takes his soul with him, Benny will show him a way out of Purgatory that only humans can use. Dean agrees, but stipulates that they find Castiel first.
===8.02 What's Up, Tiger Mommy?===
:"I am an angel in a land of abominations. There have been things hunting me from the moment we arrived."
In flashbacks, Dean and Benny interrogate a rugaru with information on Castiel's location in Purgatory. Dean forces the creature to reveal that Cas might be found near a stream some distance away. They dispatch the monster, and travel to the place he described. Cas is there, disheveled and unshaven and apparently sane again, though he does go off on a tangent once. Dean embraces him, but Castiel is not happy to have been found by Dean. Benny accuses Castiel of abandoning Dean, and Dean insists that Castiel must have been attacked. Castiel admits that he ran away. Leviathans have been hunting him, there is a bounty on him, and he hoped to stay one step ahead of them and keep them away from Dean.
Dean tells him that Benny knows of a way to leave, but he doesn't know if the portal to escape Purgatory can be accessed by angels. Dean wants him to go with them, but Castiel believes it is too dangerous. The worst of the monsters will follow him, but Dean assures him that they stopped the leviathans before and can do so again. Dean pleads with him, insisting that he will not leave without Cas. The angel relents, and goes with them.
In the present, Dean meets Samandriel at the auction where the second Word tablet is to be sold. The angel asks him about Castiel's fate, and Dean tells him that Cas did not make it back from Purgatory. The angel reveals that other angels believe that whatever Castiel's failures, his heart was always in the right place. Dean asks the angel for his own opinion. He replies that to him, too much heart was Castiel's downfall.
In a final flashback, Castiel is on the ground reaching out, and calling for Dean's help. Dean tries to hold onto him, but loses his grip.
===8.05 Blood Brother===
:"Well, I think we're clear for the moment. It does present a curious curl in the metaphysics, doesn't it? If you murder a monster in monster heaven, where does it go?"
In flashbacks Castiel, Dean and Benny come under attack by monsters and Castiel kills one with his powers. Castiel and Benny warn that it may not be possible for Castiel to get out and he is drawing monsters to them by being close to them. Both Castiel and Benny push for Dean to leave him behind, but Dean refuses to abandon his friend. Before they can argue further, Castiel senses Leviathans closing in on them and they are too close for him to teleport them out. They run, but come under attack by two Leviathans. Dean decapitates one, but the other one nearly kills Castiel before Benny decapitates her, saving Castiel to Dean's shock.
===8.07 A Little Slice Of Kevin===
:"It's where I belonged. I needed to do penance. After the things I did on Earth and in Heaven, I didn't deserve to be out. And I saw that clearly when I was there. I... I planned to stay all along. I just didn't know how to tell you. You can't save everyone, my friend... though, you try."
Flashbacks: In Purgatory, Castiel, Dean and Benny near the location Benny has been told holds the portal out and Dean argues with him about it, asking if he's sure that he wasn't lied to and Castiel indicates his lack of faith as well when asked if he wasn't supposed to be all about faith as an angel. Castiel again brings up the fact that as an angel he might not be able to make it through, but before they can discuss it more, the portal opens nearby in response to Dean's presence. Dean casts a spell that absorbs Benny's soul into his arm and he and Castiel head for the portal, but Castiel stops him, sensing two Leviathans which attack. Dean gets knocked down, leaving Castiel to fight them off by himself. Castiel is able to hold them off, but is unable to defeat them. However, while they are distracted with Castiel, Dean decapitates one from behind and Castiel holds the other one in place so Dean can decapitate that one as well. The two quickly head for the portal which is on top of a ridge and closing, but Castiel lets go of Dean, wanting to stay in Purgatory and tells him to go. Before Dean can do anything, the portal closes with him in it, leaving Castiel behind. However, Dean remembers it as losing his grip on Castiel and accidentally leaving him behind
In the present, Dean sees Castiel on the side of a roadway and outside a cabin he and Sam are staying in, but when he looks closer, Castiel is gone. Finally, Castiel appears in person to Dean in the cabin's bathroom and collapses from the teleport, having been weakened by his time in Purgatory. Castiel explains that he'd been trying to reach out to Dean, but had been too weak to do it, which is apparently why Dean kept seeing him. Castiel is unaware of how he got out of Purgatory, explaining that one minute he was on the run from the Leviathans and the next he was on a roadside in Indiana. Castiel cleans up as Sam and Dean discuss the suspicious nature of his return, which Dean doesn't believe he could've done on his own given the condition he was in Purgatory. As Sam and Dean discuss the case, Castiel watches TV and recognizes the names of the people they are looking for as future prophets. Castiel explains how there can only be one Prophet at a time and that since Kevin is one, Chuck must be dead, though he doesn't know how. This causes them to realize that Crowley is getting desperate in his search for a way to translate the Word of God.
After getting a call from Linda Tran, Sam, Dean and Castiel travel to a location to meet her and Dean calls Castiel out of the car to talk to him about his escape from Purgatory. Dean repeatedly tells Castiel he didn't leave him behind and to Castiel's confusion, he realizes that Dean blames himself for Castiel being left behind in Purgatory. Before they can discuss it anymore, Linda arrives with a demon she captured who can tell them where to find Crowley and the prophets.
Castiel joins Sam and Dean in their assault to rescue Kevin Tran and the other prophets. During the assault, Dean gets knocked down by a demon and Castiel faces off against it. When the demons uses its powers on him, Castiel is slightly affected in his weakened state, but kills the demon, which exhausts him. Reaching the outside of the locked room where Kevin is, Castiel senses that Kevin is in trouble and teleports in to face Crowley. Castiel draws his angel blade to fight the demon while Crowley draws one of his own, believing that Castiel is bluffing in his clearly weakened state. Castiel draws upon his power to smite the King of Hell, causing him to glow and his wings to appear. At first Crowley continues to believe Castiel is bluffing, but realizing that he is serious, tries to escape with the Word of God. To prevent this, Castiel smashes the tablet in half and Crowley only gets away with half of it. Once Crowley is gone, Castiel collapses as Dean enters.
Outside, Castiel, who believes he can fix Kevin's cut-off finger, discusses with Dean his escape from Purgatory. Realizing that Dean has blocked out the truth, Castiel uses his powers to show him what really happened when Dean escaped, explaining that he wanted to stay in Purgatory as his penance and it was never Dean's fault, stunning Dean as Sam joins them.
Suddenly, Castiel appears in an office where he sees a woman. The woman explains that she is an angel named Naomi and that this is a part of Heaven few, including Castiel have ever been to before. Naomi explains that the angels rescued Castiel from Purgatory, though it cost many their lives and asks what the Winchesters are up to. To Castiel's surprise, he casually explains about how the tablet is broken in two and how the Winchesters plan to go after it. Naomi orders Castiel to come when the Winchesters call and to aid them in any way they need. She also tells Castiel that he will periodically check in with her, which she refers to as his penance and tells him that he will not remember or even realize he was gone before sending him back.
Back with Sam and Dean, they explain that they want to go after Crowley and get the other half of the Word of God tablet and ask Castiel to join them. Castiel agrees.
===8.08 Hunteri Heroici===
:"No. I still want – I still need to help people. So... I'm gonna become a hunter."
Castiel, who has muted his ability to hear what other angels are saying in his head asks Sam and Dean to become a hunter like them and brings them a case he has found in a newspaper: a man's heart literally burst out of his chest. Sam and Dean reluctantly agree to train him, but insist on him riding in the Impala with them rather than teleporting. Castiel agrees, but is annoyed that he can't sit "shotgun" like he wants.
At the morgue, Castiel uses his supernatural senses to tell everything about the man's health, which annoys Dean and is surprised when Sam reveals the man was having an affair which Castiel was unable to tell with his abilities. While questioning the man's wife who they believe to be a witch, Castiel decides to play "bad cop" and angrily demands to know why she killed her husband before Dean calms him down. It turns out the wife knew about the affair and was having one of her own as part of a deal between her and her husband which rules her out as a suspect. They later visit a scene where a man committed suicide, but stayed in the air for a minute before falling. Sam and Dean liken it to cartoons, but Castiel is just confused by what they mean and their explanation.
At a motel, Castiel watches cartoons and believes he finally understands them, but clearly is wrong in his beliefs about what they mean. Unable to find a connection between the two victims, Sam and Dean decide to go to sleep and Castiel, who doesn't need to sleep tells them he plans to watch over them. Just then, Castiel, who is mentally tuned into the police band, learns that a bank has been robbed and tells Sam and Dean that it "sounds Looney."
The three travel to the bank where they find that a one-ton anvil has crushed a security guard and that the bank was robbed with the robber getting away clean, leaving a black hole drawn on the wall and on the safe deposit box he robbed. After Sam leaves to look at the files on other similar robberies, Dean has Castiel move the anvil to find an X marked on the ground underneath it. Dean explains how in cartoons stuff like this happens and how in cartoons a drawn black hole can be used as a door, which allowed the robber to get in and out with what he wanted. However, Dean and Castiel discover that for some reason the "door" is no longer working.
At the motel, Castiel reads John's Journal and compliments his handwriting. Dean expresses worry that about Castiel's state after his return from Purgatory and asks him to go check in Heaven to see what the angels have to say about his return, but Castiel angrily refuses when he insists. Castiel explains that while he caused a lot of suffering on Earth when he declared himself God, he devastated Heaven and killed thousands of his own kind. Castiel fears that if he goes back to Heaven and sees the devastation he has wrought, he will kill himself out of his remorse over it. Before they can discuss the subject anymore, Sam returns and shows them that wherever there was a robbery, reality was warped for fifty yards around it for five to ten minutes, causing the weird effects including various minor ones, all based off cartoons. All of the belongings that were stolen belonged to people at the Sunset Hill Retirement home and the three decide to go check it out, believing their thief might be there. When Dean tells them to gear up because "it’s wabbit season," Castiel doesn't get the reference and tells him he didn't pronounce it correctly.
At the retirement home, Sam, Dean and Castiel question the residents on the loss of their valuables. Castiel and Dean question an old woman named Mrs. Tate who flirts with a clearly uncomfortable Castiel who she says reminds her of her third husband. After Mrs. Tate tells them that a cat belonging to one of the resident's talks sometimes, Castiel decides to interrogate the cat. When Sam and Dean call him to follow them, Castiel tells them that he's close to cracking the cat and tells the cat he's not through with him before leaving. Unknown to him, the cat calls him a "dumbass" once he goes. The three visit the room of Fred Jones, a psychokinetic Sam and Dean are familiar with and believe to be causing the crazy happenings with his ability to reshape reality. Dean is able to prove the theory by hitting himself in the head with a book, but when Castiel questions killing Fred to solve the problem, he gets them thrown out. Castiel offers to go back and teleport Fred out, but Sam and Dean decide to play it more low-key as with Fred's powers, Castiel could be adversely affected. Sam and Dean decide to return that night and have Castiel stay there invisible to keep an eye on Fred. After a cake explodes, Castiel calls Sam and Dean back, but they learn that while he was distracted, Fred has disappeared. While trying to figure out what to do, Mrs. Tate tells Castiel that a bracelet a nurse is wearing was one of the things stolen from her and Castiel asks where the nurse got it from.
After learning that the nurse's boyfriend gave the bracelet to her, they travel to his apartment where they find him lying on the floor, shot in the gut. At Dean's request, Castiel heals the wound and the man explains that he learned of Fred's powers by accident and told Doctor Mahoney at the home. Mahoney, who has been stealing from the home for years and the man worked together to rob people using Fred's powers to access their hiding places, but when the man found out Mahoney planned to rob the bank one more time then kill Fred, he protested and was shot. Castiel, Sam and Dean leave to go back to the bank and Castiel wonders if Fred knows what's going on, but Dean tells him Fred seems to be living in a dream world, unaware of anything.
At the bank, Castiel and Sam search for Fred while Dean enters the bank to deal with Mahoney. Searching the parked cars nearby, Castiel senses Fred's power and is able to find him. Fred is unresponsive and when Sam expresses a desire to be able to talk to him, Castiel enters Fred's mind and pulls Sam with him.
In Fred's mind, which initially looks like a cartoon and shifts occasionally, Castiel explains what he did to Sam and watches as Sam confronts Fred and tries to convince him to wake up. While Fred doesn't believe it, Castiel tells him that what Sam is telling him is true. Castiel listens as Sam explains how living in a dream world is nice for awhile, but you can't run from something forever and that when it catches up, if you don't wake up, trying to keep the dream alive will destroy you. Sam's speech clearly effects Castiel while it convinces Fred to wake up from his dream world.
Castiel, Sam and Fred quickly enter the bank to help Dean and Castiel watches as Fred forces Mahoney to kill himself. Fred expresses fear that as he ages further, he will lose control again and cause more chaos and pain and asks for a way to stop it forever. Castiel offers to remove Fred's power, but warns that it will be painful and dangerous and if he does it, he's not sure how much of Fred will be left. After a brief hesitation, Fred agrees and asks Castiel to do it.
Castiel removes Fred's powers and they return him to the retirement home where he is left in a mentally distant state. However, Castiel is able to tell that Fred is happy nonetheless and listening to "Ode To Joy" in his mind. Dean compliments Castiel on his actions and even offers to let him ride shotgun in the Impala, but Castiel refuses.
As Castiel starts to explain why he can't come with Sam and Dean, he is pulled to Heaven where he meets with Naomi again. Naomi refuses to let Castiel return to Heaven as he wants and Castiel tries to convince her to allow it, explaining that he has been trying to escape what he has done, but has realized that he has to return to make things right. Naomi tells him that he is making things right by doing what he's told, but that unless she summons him, he stays out of Heaven. When Castiel asks what he should do, Naomi asks him what he wants to do, causing him to give it careful consideration for the first time.
Back with Sam and Dean, Castiel tells them that he will stay and watch over Fred for a few days to make sure he is safe but he is unsure what he will do after that, he has accepted that he can't run from what he did anymore. Sam and Dean leave and Castiel takes a seat next to Fred, listening to "Ode to Joy" with him.
===8.10 Torn And Frayed===
:"I don't know. But the amount of pain an angel must be in not just to manifest through shrubbery but to burn – Dean... we have to find him before it's too late."
As his penance, Castiel has turned back on his "angel radio" and is now helping people in need. Sensing a baby girl very sick with the doctors unable to figure out what's wrong with her, Castiel travels to a park where she is with her mother, crying and heals her illness. Before the mother can thank him, Castiel disappears.
Castiel is summoned by Naomi to Heaven where she reveals that she has gotten a distress call from Samandriel. Castiel is shocked as he believed the angel to be dead, but Naomi explains that he is merely missing. Castiel tells Naomi that he will need help as Crowley will have warded his base with Enochian symbols to protect against angels and Naomi tells him to take whatever he needs, but orders him to make it seem like his idea to the Winchesters.
Castiel finds Dean asleep and without Sam and startles him. Castiel explains the situation and asks where Sam is, but Dean tells him that Sam is not there at the moment and that they will do this without him. Castiel explains that all he knows is that Samandriel is in the vicinity of Hastings, Nebraska, but doesn't know more than that. After he explains that an angel in distress can cause weird effects on the environment and that he needs Dean's help as he may need to interact with people, Dean starts a search for information on the Internet.
After learning of a man who heard a voice from a bush that burst into flames in Geneva, Nebraska, Dean and Castiel travel there and pose as reporters to question the man. He reveals the words he can remember and Castiel recognizes it as Enochian translating into "I obey." Believing that Samandriel must be close, Dean and Castiel search nine nearby factories and find the right one when Castiel recognizes homeless men nearby as demons and can't sense anything in the factory. Realizing they are outnumbered, Dean decides to go to Kevin Tran for help to create more demon bombs.
Dean and Castiel visit Kevin in Garth's houseboat and ask for the ingredients. Kevin is annoyed as the ingredients are very rare and nearly impossible to find, but Castiel takes a list and looks for them anyways. Castiel is able to gather all of the needed ingredients, but also gets Sam despite Dean's insistence against it as they need all the help they can get. Recognizing that there are issues between Dean and Sam, Castiel yells at them to pull it together and work together on the problem.
The three travel to the warehouse where Samandriel is and Castiel shows them the symbol they need to neutralize in four places so he can enter. He also gives Sam his angel blade as it can kill demons as well as angels. Castiel stays behind as the two enter the warehouse and neutralize the symbols and demons inside. Once the symbols have been painted over, Castiel is able to enter the warehouse but is left weakened by the other symbols so Sam gives him back his blade. As Sam and Dean try to break down the door to the room where Samandriel is being tortured, the sounds of the torture trigger a flashback where Castiel remembers Naomi having him tied down to a chair and approaching his eye with an unknown instrument while he screams. Sam and Dean eventually manage to break in and kill the demons with Samandriel while Castiel rescues the angel. On Dean's order, Castiel takes Samandriel outside while they deal with the last demon.
Outside, Castiel tries to comfort Samandriel, telling him he is going to take him back to Heaven, but Samandriel is frightened as he revealed major angel secrets under torture. Samandriel realizes Naomi is controlling Castiel and tries to warn him, but after learning that Samandriel revealed the existence of the angel tablet to Crowley, Naomi orders Castiel to kill him. With no other choice, Castiel draws his blade and stabs Samandriel, killing him. Castiel is horrified that he murdered another angel, but Naomi calls Samandriel a traitor and Castiel a hero, explaining that the angel tablet's existence is a secret any angel would die to protect, including her and it has the potential to cause great harm if it falls into Crowley's hands as it could potentially be used to seal all angels inside Heaven. On Naomi's orders, Castiel claims Samandriel was corrupted by Crowley and he was forced to kill him in self-defense and that he will be taking him to Heaven to be put to rest (in reality so Naomi can determine just how much he broke). However, his odd behavior and the fact that his eye starts bleeding before he leaves draws the Winchesters' suspicions that he is possibly being controlled.
===8.16 Remember The Titans===
After their defeat of Zeus and their return to the lair of the Men of Letters, Dean, recognizing that Sam is not doing as well as he claims to be while enduring the trials to close the Gates of Hell, prays to Castiel for aid, but Castiel does not respond to Dean's prayer, prompting Dean to wonder where his friend is.
===8.17 Goodbye Stranger===
:"If you're referring to the pizza man... Yes, I remember the pizza man. And it's a good memory."
Castiel is shown ruthlessly killing a copy of Dean to which Naomi comments that "he is ready" and it is discovered that he has killed thousands of copies. Naomi sends Castiel to locate the angel tablet to stop Crowley from getting his hands on it. His killing of the demons draws Sam and Dean's attention and he arrives in time to save a weakened Sam from a demon that was attacking him. Castiel binds a demon possessing Wendy Rice, in a devil's trap and explains to the brothers that he looking for the other half of the demon tablet while Crowley is looking for a parchment that can translate the tablet without a prophet. Castiel tortures the demon for information, with his angel blade, and when the demon is about to reveal the truth to Sam and Dean, he kills the demon on Naomi's command. 
Castiel instantly heads to the hotel the demon revealed they are holding the hostage. Sam and Dean noticing this, hurriedly heads to the hotel as well and when they arrive they find that Castiel has already killed all the demons in the room. They discover that Meg is the hostage and everyone gathers to hear what's been happening. Meg explains to them that Crowley and his demons are actually looking for the angel tablet, much to the shock of Sam and Dean, since they thought they Crowley was searching for a parchment. Castiel, having been permitted by Naomi to let Meg explain, tells Sam and Dean that this revelation is a shock as well to cover up his story before. Afterwards, Castiel helps Megs with her wounds and Meg starts to flirt with him, reminiscing about their kiss in the past. They also discuss how everything was simple when the Apocalypse had started and how much things have changed between them. Meg subtly implies that she wants to have sex with Castiel when everything is over, something he doesn't pick up on at first, but accepts when he catches on.
After Dean, Sam and Castiel, with the help of Meg, discover the crypt holding the angel tablet, Dean and Castiel go ahead to retrieve it while Meg and Sam stay behind and keep watch on any demons coming through. After Castiel notices that the entrance to the crypt is blocked by a wall, he uses his angelic powers to shatter the wall. Dean goes through and Castiel points out to Dean where the angel tablet is since he cannot retrieve it himself because the box is angel proof. After Dean removes the angel tablet from the box, Castiel asks Dean to hand it over so he can return it to Heaven but Dean, being suspicious of Castiel for awhile now, tries to get out of it. Castiel, while under the control of Naomi, is forced to attack Dean and after a brutal bashing, Castiel struggles to land the finishing blow onto Dean. Castiel eventually manages to break free and picks up the angel tablet, regaining complete control of himself and severing Naomi's connection to him. Castiel heals Dean's injuries and apologizes, explaining what happened. Before leaving he heals Dean and tells him that he must protect the tablet from Naomi, Crowley and even Dean himself for some reason.
Castiel is later seen on a bus with the angel tablet heading to a unknown location. While the angels are shown to be unable to find him, Naomi is at least somewhat pleased as he is doing what he is meant to do: protect the angel tablet.
===8.21 The Great Escapist===
:"In the words of a good friend....Bite me."
Castiel hides from the angels looking for him and the angel tablet by moving rapidly through the various Biggerson's restaurants, confusing them as they all look the same. Eventually the angels Ion and Esper catch him by slaughtering all of the people at one of the Biggerson's, drawing his attention. Naomi arrives and reveals that Castiel has been forced to do many horrible things in his lifetime, but was never very good at following orders and his memory was always erased of it. Naomi demands the location of the angel tablet, but before she can start torturing him, Crowley shows up and kills Esper, wounds Ion who is on his side and drives away Naomi with an angel killing gun he has made. He then has Castiel taken to his office after shooting him in the stomach.
At Crowley's office, he has figured out where Castiel has hidden the tablet, inside himself and painfully removes it by digging into Castiel's stomach wound. Crowley then leaves Castiel alone with Ion after getting a call from two of his demons that Kevin Tran has figured out their deception. Ion reveals that he has always known the truth of the horrible acts he has done and has become disillusioned with Heaven. While Ion is distracted, Castiel digs the bullet out of his stomach, knocks Ion down and shoves the bullet through his eye, killing him.
Later, when Sam and Dean are driving back to the Bunker in the Impala, a wounded Castiel appears on the road in front of them, asking for help.
===8.22 Clip Show===
:"I know, I'm the one who broke it. There was a time when I thought I could lead our people, but I was mistaken. I spilled so much blood. And I've tried to atone for my sins and I did penance. And I betrayed my friends to protect our secrets, but I've just failed. And now --"
At the Bunker with Sam and Dean, Castiel is slowly recovering from his wound. Though he repeatedly tries to make amends with Dean, things are strained between them due to Castiel abandoning them and not trusting Dean again. When Sam finds the record of a weird exorcism, Castiel watches it with them and recognizes one of the changed words to mean "cleanse." Castiel offers to get supplies for the Bunker to try to make up for what he has done, but Dean refuses and he and Sam leave to check out the priests who performed the exorcism.
In an attempt to make up with Dean, Castiel goes to get supplies anyway and is annoyed when he is unable to get pie for Dean and threatens the clerk of the mini-mart. However, Metatron shows up to defuse the situation.
Talking with Metatron, the two discuss the state of Heaven and Metatron reveals that Naomi is only the leader of one of many factions fighting for control of Heaven and that he wants to seal up all angels inside to force them to have a big "family meeting" and work out their differences. As the Scribe of God Metatron knows the trials to seal up Heaven even without the angel tablet and wants Castiel to do them. Castiel eventually agrees and Metatron reveals that the first trial is to cut out the heart of a Nephilim, one of which, Jane, is their waitress. Castiel is reluctant, but Metatron convinces him.
That night, Castiel and Metatron stalk Jane who attacks them. Castiel loses his angel blade in the fight, but eventually retrieves it and kills Jane by stabbing her through the throat from behind while she is distracted fighting Metatron.
===8.23 Sacrifice===
:"We're gonna shut it all down -- Heaven, Hell, all of it."
Preparing for the second trial, Castiel asks Metatron about God who Metatron says is gruff, kind of sexist but eminently fair. Metatron reveals that the second trial is to get the bow of a Cupid and that one is to make a man named Dwight Charles fall in love so they will have a chance.
Waiting in the bar where Dwight works for the Cupid to arrive, Castiel reads through personal adds in the newspaper in an attempt to help speed the process up, freaking Dwight out when he tries to ask him his preferences to help. Naomi arrives with two angels who capture Metatron. Castiel has a stand-off with them with his angel blade until Metatron defuses the situation by telling him to let him go.
Needing help to finish the trials, Castiel approaches Dean who is not keen to help as Sam is working on the third demon trial which is to cure a demon, in this case, Crowley. Sam convinces Dean to help and they eventually spot the Cupid, Gail, make Dwight fall in love with his regular customer Rod. Dean and Castiel confront Gail outside and while Castiel initially wants to use force to get the bow, Dean convinces him to talk to Gail instead. Gail, who is worried about the chaotic state of Heaven, agrees to help them, but Castiel ends up having to cut the bow out of her hand.
Afterwards, Dean and Castiel try to get the third trial from Kevin who has the angel tablet, but he tells them that while he sees trials on the tablet, he doesn't see anything about the heart of a Nephilim or the bow of a Cupid. At that moment, Naomi arrives and while Castiel wants to fight, she insists she is just there to talk and Dean convinces him to hear her out. Naomi reveals that Metatron really plans to expel all angels from Heaven as revenge for his own exile and shows remorse for her actions, offering to hear Castiel out if he truly wants to return to Heaven and revealing that Sam will die if he completes the trials. Castiel refuses to believe her, but takes Dean back to Sam before returning to Heaven to find out the truth for himself.
In Naomi's office, Castiel finds her dead with her own torture drill stabbed in the back of her head and is confronted by Metatron who confirms what Naomi told him. Metatron takes Castiel's grace to act as the third part of the spell he is performing, turning Castiel human and then, telling Castiel to find him when he dies and goes to Heaven to tell him his story, sends Castiel back to Earth.
On Earth, Castiel is forced to watch as all the angels fall from Heaven to Earth.
===9.01 I Think I'm Gonna Like It Here===
:"I didn't want to hurt any of them. I want to help you. I will devote my life to helping you all."
Now human, Castiel makes his way down a road in Colorado, still able to hear angel radio. His distraction causes him to nearly get hit by a truck and the driver offers him a ride after telling him there's no cell phone reception in the area and Castiel declining water. Castiel is also stunned by his injured palm, something he has never experienced before.
Dropped off at a gas station, Castiel reluctantly takes money from the man and on his way to a payphone, is met by the angel Hael who is looking for guidance. Castiel suggests she use the chance to make a new start and that she visit the Grand Canyon when she expresses interest in it after revealing that she created it. Castiel agrees to go with her, but first calls Dean and reveals his new human status. He also recognizes Ezekiel when Dean mentions he is there to help Sam and tells him that Ezekiel can help. Dean convinces Castiel to help him and Sam instead of Hael and when he tells her this, she knocks him out and kidnaps him.
Driving in Hael's car, she reveals that her vessel is deteriorating and that she plans to possess Castiel himself to make her stronger, believing its the least he can do after he caused the fall of the angels from Heaven. Needing to stop Hael, Castiel puts on his seatbelt and then crashes her car, sending her through the window and incapacitating her while he survives with minor injuries. Castiel retrieves Hael's angel blade but declares that he is going to help all of the angels that have fallen rather than killing her. However, Hael threatens to broadcast his location to all of the angels looking for him if he doesn't allow her to possess him and he is forced to kill her with her own blade.
That night, Castiel visits a laundry mat and goes to clean his bloodstained trench coat and clothes, but realizes that he is hungry and thirsty. With not enough money to do both, Castiel abandons his clothes, including his trench coat, steals new ones and buys water (which he drinks thirstily) and food from a vending machine.
===9.03 I'm No Angel===
:"Yes, there's more to humanity than survival. You... look for purpose, and you must not be defeated by anger or despair. Or hedonism, for that matter."
Castiel, making his way towards the Bunker, stays at a homeless shelter where he works picking up trash in the nearby churchyard. Castiel is still trying to get a handle on being human and has taken on the name "Clarence" as an alias, the name Meg always called him. After finding two priests tortured and murdered by angels, Castiel quickly moves on.
At a homeless camp, Castiel discusses being human with a homeless man. When he mentions he has trouble sleeping, the man suggests he "count sheep," confusing Castiel. Castiel goes to sleep in a broken-down bus, but is awakened when an angel arrives nearby to kill him. Sensing the angel, Castiel draws his angel blade, but the angel catches him by surprise and slashes him in the shoulder with his own blade. The angel is surprised to realize that Castiel is human and Castiel uses the distraction to kill him. Castiel quickly hitchhikes a ride on a meat truck to Detroit to get away from further angels.
In Detroit, Castiel has to decide between getting an Enochian tattoo that can ward him from being sensed by angels and getting food and he gets the tattoo, leaving him with no money for food. He later goes to a church where he meets a woman praying for angels to save her sick husband and Castiel tries to tell her the truth about the state of Heaven. However, the woman has too much faith to believe him and suggests that Castiel pray himself and to keep faith. Castiel digs through a garbage can for food and meets waitress April Kelly who gives him a sandwich. That night, Castiel is still siting outside the restaurant and April takes him home.
At April's apartment, she dresses his wound and the two have sex. Afterwards, Castiel tells April about how he made a mistake out of vanity and how it led to bad things. The next morning, Castiel dresses in his washed clothes, but is unable to find his angel blade. April reveals that she has it and that she is in fact a rouge reaper who is hunting him for the angels. April tortures him with his own angel blade for information on Metatron and his spell, but Castiel tells her he didn't know the truth until too late and that his grace was the final ingredient. Castiel tells April it would be foolish to kill him as if his Grace was the key to making the spell work, he may be the key to reversing it. Before April can go any further, Sam and Dean burst in and April stabs Castiel with the angel blade, killing him. After Dean kills April with the angel blade she used to kill Castiel, Ezekiel takes control of Sam and resurrects Castiel, healing all the damage April did to him. Unable to tell them the truth about Ezekiel, Dean claims Sam was knocked out and he made a deal with April to not kill her if she resurrected Castiel then went back on it.
At the Bunker, Castiel enjoys the abundance of food and tells Sam and Dean that he finally understands humanity more. He also admits to having sex with April to their shock and doesn't understand when Dean asks him if he used protection. Castiel goes off to eat a burrito, but after Ezekiel tells Dean that Castiel must leave or he must due to how dangerous it is to be around Castiel with angels chasing him, Dean reluctantly orders Castiel to leave as Ezekiel leaving would mean death for Sam.
===9.06 Heaven Can't Wait===
:"Nobody told you. Nobody explained. You're just … shoved out kicking and screaming into this human life, without any idea why any of it feels the way it feels, or why this confusion, which feels like it's... a hair's breadth from terror or pain. You know, just when you think you do understand, it'll turn out you're wrong. You didn't understand anything at all. Guess that's just how it is when you're new at this. You know, it wasn't that long ago when all I'd need to do to ease your pain was touch you."
Working as a sales associate at a gas station- and also serving as a baby-sitter for his boss, Nora, although he initially assumed it was a date-, Castiel calls the Winchesters for help after two people in his area simultaneously combust. With Dean's aid, Castiel determines that the victims were killed by a Rit Zein, a class of angel healers that kill mortally wounded angels, but is nearly killed by the Rit Zein, Ephraim, before Dean manages to provide him with an angel blade. After Ephraim is killed, Dean drives Castiel back to the gas station and leaves him to resume his job.
===9.09 Holy Terror===
:"I... I did what I had to. I became what they've become. A barbarian."
Investigating recent conflicts between angels, Castiel initially aids Sam and Dean before "Ezekiel" sends Castiel away, forcing Castiel to pray for aid. His prayers are answered by Muriel, a neutral angel in the war, who explains that the current conflict is between factions led by the angels Bartholomew and Malachi, but the two are captured by Malachi and his ally Theo. Muriel is killed while Malachi tortures Castiel for information about Metatron, but when Malachi leaves, Castiel is able to trick Theo into releasing him, allowing him to steal Theo's grace and restore at least some of his powers. Having learned from Malachi and Theo that Ezekiel died in the fall, Castiel calls Dean to warn him about "Ezekiel," but the renegade angel manages to escape.
===9.10 Road Trip===
:"I prefer the word trusting. Less dumb. Less ass."
Dean calls Castiel to the bunker and tells him about Sam being possessed. Castiel consoles Dean and suggests that Sam could cast the angel out if he knew he was being possessed and proposes using Crowley’s help to bypass the angel and talk directly to Sam.
Later when they manage to track Gadreel, Castiel uses his powers to knock him unconscious. Castiel identifies Gadreel as the sentry who allowed Lucifer into the garden. He becomes red with fury and blames Gadreel for the apocalypse and accuses him of being weak. Later he removes Sam’s tattoo allowing him to get possessed by Crowley. When Gadreel is cast out, Castiel tells Sam that it will take time to fully heal him and stays with him while Dean drives away.
===9.11 First Born===
:"You know, old me -- I would've have just kept going. I would've jammed that needle in deeper until you died because the ends always justified the means. But what I went though -- well, that PB and J taught me that angels can change, so... who knows? Maybe Winchesters can, too."
In the process of healing Sam, Castiel recognizes a part of Gadreel’s grace inside of him, but it fades each time he heals him. Castiel suggests extracting the grace and doing a spell to track Gadreel. The Grace Extractor was successful in removing a part of Gadreel's remaining grace, but the process proves to be dangerous to Sam as his body began to revert to the state it was in before Gadreel possessed him. After a while Castiel stops the extraction and heals Sam fully; he doesn’t believe that tracking Gadreel is worth Sam’s life. Castiel admits that the old him would have thought that the end justifies the means, but being human has changed Castiel’s view on Sam and taught him a few things and now he understands what guilt feels like. They try the tracking spell but it doesn’t work. Castiel believes that Metatron is the key to fixing everything, and tries to convince Sam to ask for Dean’s help to no avail.
===9.14 Captives===
:"No. Angels fighting angels has to stop somewhere. Might as well stop with me."
In Castiel’s attempt to track down Metatron, he learns of a faction of angels who wanted to live peacefully led by an angel named Rebecca; however they were all killed by Bartholomew. Castiel later is captured and taken to HQ where he meets Bartholomew,who is happy to see Castiel; he tells him he aims to find Metatron and restore angels to heaven and tries to make Castiel join his side. Bartholomew then tortures an angel for information and asks Castiel to kill him, saying that he needs proof that Castiel can do what has to be done. When Castiel refuses, Bartholomew tries to attack him; Castiel easily overpowers him but doesn’t kill him. Bartholomew however lunges for Castiel again, and Castiel is forced to kill him. Later Castiel is standing at Rebecca’s grave, where one of Bartholomew’s henchmen approaches and tells him that he and other angels are willing to join Castiel.
===9.18 Meta Fiction===
:"I miss my wings. Life on the road... smells."
While Castiel refuses to lead other angels against Metatron, he is shocked when he is visited by what appears to be Gabriel, returned to life and willing to rally the angels against the former Scribe. Castiel realizes that 'Gabriel' is just an illusion, but is forced to accept the mantle of leader despite knowing that this is what Metatron wants, as well as learning that his stolen Grace will eventually kill him.
===9.21 King of the Damned===
:"Dean, this angel-on-angel violence -- it has to end. Someone has to say, 'enough.'"
Castiel contacts Sam and Dean for help interrogating one of Metatron's followers, who reveals that Metatron has discovered a back door into Heaven that would allow the angels to return to Heaven. Castiel attempts to convince Gadreel that he is fighting for the wrong side in a meeting.
===9.22 Stairway to Heaven===
:"It's Enochian. I believe it's some sort of riddle. 'Why is six afraid of seven?' Now, I assume it's because seven is a prime number, and prime numbers can be intimidating."
An angel blows himself in an ice cream parlor, killing one of Metatron's angels and several humans, and claims to have done it in Castiel's name. Metatron is revealed to have been brainwashing other angels to commit suicide assaults and claim that they are doing it in Castiel's name to portray Cas as a despot willing to resort to any means of victory before his grace burns out. Metatron forces Castiel into an impossible situation by manipulating Castiel's followers to perceive him as unreliable, presenting Dean as an unstable killer due to the Mark of Cain after Tessa stabs herself with the First Blade while Dean was interrogating her. While Castiel's followers thus abandon him, Gadreel is convinced to side with Castiel, although Dean attacks Gadreel when he attempts to explain the situation to them.
===9.23 Do You Believe In Miracles?===
:"I'm no leader, Hannah. I never was. I just want to be an angel."
With Dean on lockdown due to the Mark's influence, Castiel and Sam talk with Gadreel, who reveals that Metatron intends to set himself up as the new God. With the power from the angel tablet making Metatron virtually unstoppable, Castiel and Gadreel attempt to infiltrate Heaven to shatter the tablet while Sam and Dean try to find Metatron. Metatron stabs Dean, but while Castiel and Gadreel are locked up in Heaven's prison, but Gadreel sacrifices himself to free Castiel and convince Hannah to help him. With the angel tablet destroyed, Castiel forces Meatron to confront him and reveal his true disdain for humanity and the other angels after Castiel activates 'angel radio' to broadcast a message to the rest of the angels. Metatron is overpowered and locked up, but Castiel is left facing both his new responsibilities as the other angels' perceived leader and his own imminent death, unless he can cure his diminishing grace.
===10.01 Black===
:"Well, perhaps I've been down here with them for too long. There's seemingly nothing but chaos. But not all bad comes from it. Art. Hope. Love. Dreams."
Castiel is approached by Hannah to help her track down renegade angels Daniel and Adina, who have chosen to remain on Earth in favor of the freedom they have on Earth. Although Castiel is forced to kill Daniel to save Hannah despite his understanding of Daniel's motives, he continues to argue in favor of angels taking on human values.
===10.02 Reichenbach===
:"Listen to me, Hannah. You don't want this. I have seen what -- I've made deals born of desperation, and they always end in blood and tears -- always."
Sam contacts Castiel to alert him to Dean's transformation into a demon due to the influence of the Mark of Cain. With Castiel still dying due to his stolen Grace, Hannah approaches Metatron for aid, but although Metatron hints at possessing a fragment of Castiel's original Grace, Castiel stops her from making a deal, not wanting to resort to evil means to save his life.
===10.03 Soul Survivor===
:"It’s what the humans do. They say they’re fine. And even if I—I don’t look it, you say I look well, and that way, we avoid talking about something we can do nothing about."
As Castiel and Hannah travel to the Bunker to help Sam cure Dean, they are ambushed by Adina, seeking revenge for Daniel's death. However, Crowley intervenes in time to kill Adina, transferring her grace to Castiel and restoring his own powers. Now 'recharged', Castiel makes it to the bunker in time to stop Dean from killing Sam. allowing Sam to complete the cure.
===10.07 Girls, Girls, Girls===
:"You did the right thing. You hurt him, but you gave him a reason, something he could use to move forward and make sense of his loss. I had to take my vessel from his family -- twice, actually. Jimmy Novak. He was a good man. He was married, had a daughter...Claire."
While tracking rogue angels, Castiel and Hannah are confronted by the husband of Hannah's vessel. She initially claims that 'Caroline'- her vessel- is having an affair with Castiel, but after talking with Castiel about his own history with his vessel's family, Hannah decides to return to heaven so that Caroline can return to her life, prompting Castiel to do some research into the Novaks' lives since his departure.
===10.09 The Things We Left Behind===
:"Yes, well, um… Before, I was very self-assured. I was convinced I was on this righteous path. Now I realize that there is no righteous path. It’s just people trying to do their best in a world where it’s far too easy to do your worst."
Discovering that Claire Novak- the daughter of his current vessel and a one-time former vessel herself- is currently in juvenile hall, Castiel attempts to release her by posing as her father. However, Claire is unwilling to talk to him after he admits that Jimmy is dead, blaming Castiel and the Winchesters for the loss of her father, prompting her to run away. Despite this, the three still save her from a loan shark's attempt to sell her to pay off his debts, resulting in Dean killing the loan shark and his men.
===10.10 The Hunter Games===
:"I thought there would be a connection -- one extremely messed up human to another. You could explain why you murdered her only friend."
Despite trying to help Claire, Castiel also tries to help Dean find a cure for the Mark by bringing Metatron down to Earth so that the Winchesters can interrogate him for information. Although Claire runs away and Metatron just taunts the Winchesters without giving them anything useful, Claire eventually realizes that she can't hold the Winchesters and Castiel fully responsible for Jimmy's death, assuring Castiel that she'll keep in touch with him in the future.
===10.14 The Executioner's Song===
:"You'll kill them all? You are Adam and Eve's firstborn. Your descendants are Legion."
When Castiel discovers that Cain is killing all of his descendants in the belief that his bloodline is tainted, the Winchesters retrieve the First Blade in order to stop him. Following Cain's death, Dean entrusts the Blade to Castiel rather than Crowley.
===10.17 Inside Man===
:"We have your grace, Metatron. You're mortal now. So you will answer our questions, or Sam will, um... What's the phrase? Blow your fricking brains out. It's called leverage, Metatron."
With Dean increasingly succumbing to the influence of the Mark, and Castiel unable to retrieve Metatron from Heaven directly, Sam and Castiel enlist the aid of a psychic to contact Bobby for help in getting Castiel back into Heaven and then breaking Metatron out. Back on Earth, Castiel removes Metatron's Grace so that they can interrogate him more effectively, but although Metatron admits that he actually has no cure for the Mark, he does reveal that a fragment of Castiel's grace still exists, prompting Castiel to take him on a trip to retrieve it.
===10.18 Book Of The Damned===
:"What's the maddest thing a man can do? Let himself die."
While taking a break from their road trip to regain Castiel's grace, Cas and Metatron stop at a diner so Metatron can eat and pontificates on his experience being human. After taking Metatron to the bathroom, Castiel leads his prisoner out the back, where the two run into a cupid who blames both of them for what they have done to Heaven, and attacks them. In the ensuing fight, the cupid gets the upper hand, and as he is about to deliver a death blow to Castiel, Metatron sneaks up behind the cupid and kills him.
Metatron then finally takes Castiel to the library where he hid the remnants of Castiel's grace, the location concealed in assorted quotes in the various books throughout the library. During the search for the right book, Metatron talks to Castiel about what he will do once Heaven is in order before stunning him with a spell. Metatron reveals that he really came for the demon tablet as well as the grace. While Metatron searches for the tablet, Castiel finally manages to locate his grace in a copy of Don Quixiote. Metatron flees with the demon tablet and Castiel ingests his grace, restoring him to full power once more, albeit still with broken wings.
After returning to the Men of Letters Bunker, Castiel lies to Dean by stating that Hannah managed to get the location of his grace out of Metatron. He finally meets Charlie Bradbury who jokingly asks him to heal her carpal tunnel. Taking her seriously, Castiel heals the affliction and even her bullet wound. He then celebrates his full return with his friends.
===10.20 Angel Heart===
:"Your husband is in Heaven. Amelia, I promised to protect your family, and I failed."
Castiel gets a call that Claire Novak is in the hospital in Tulsa, Oklahoma as he is in her emergency contacts on her cell phone and calls Sam and Dean to help him deal with her. Claire is unhappy to see them, but explains that she is looking for her long-missing mother who had disappeared two years earlier while searching for Castiel. Claire has tracked Amelia to Tulsa as the last place she was and was interrogating Ronnie Cartwright, the last person to see Amelia before she was knocked out. Castiel, upset that he has broken his promise to his vessel Jimmy to watch out for his family, insists on helping Claire locate her mother, but they discover her gone. Castiel and Dean decide to visit Ronnie Cartwright themselves while Sam tries to cut Claire off at her motel.
At the bar, Castiel gets worried when Dean uses force to intimidate Ronnie into talking, knowing that it is a symptom that the Mark of Cain's effects on Dean are getting worse, but they learn that Ronnie sent Amelia and several others to a faith healer named Peter Holloway. Ronnie explains that Holloway is the real deal, having healed his blindness, but that he quit after seeing Holloway cut the people sent to him. Castiel and Dean determine that Holloway must be another angel, but Castiel can't figure out why he'd cut people. After meeting up with Sam and Claire who are hacking Amelia's credit card records, Castiel and Dean tell them of Holloway and learn that Ronnie has been murdered. Reluctantly taking Claire along to investigate, Castiel tells Sam that Dean is getting worse. Posing as FBI, Castiel determines that the wound was caused with an angel blade but that it seems bigger and has left three strange marks he can't identify, confirming that they are dealing with an angel. After Sam figures out Holloway's location, they go to check out his farm, leaving Dean behind with Claire due to his worsening condition.
At the farm, Castiel searches the barn and finds Amelia and a few other victims. He is able to wake Amelia who is glad to see him despite being able to tell that Jimmy is no longer in his body. Castiel confirms Jimmy's death and apologizes for breaking his promise to protect her family. However, Amelia tells him that as long as Claire is safe, he has kept his promise. Castiel is unable to wake the other victims or heal Amelia's injuries, something that disturbs him as he has never not been able to heal someone before. When Claire and Dean arrive, Castiel leaves to search for Sam with Dean, leaving mother and daughter alone. After finding Sam, Castiel is stunned to hear that Holloway is actually Tamiel of the Grigori as those angels were wiped out millennia ago. Sam explains that some survived and are now feeding on human souls. Realizing that Tamiel is after Amelia and Claire, the three rush back to the barn where Tamiel has just killed Amelia. Castiel and the Winchesters fight Tamiel, but even together prove no match for him. Tamiel nearly kills Castiel with his own angel blade, but is instead killed by Claire from behind with his own angel sword.
The next day, the Winchesters and Castiel decide to send Claire to Jody Mills until she can get on her feet. Claire, presumably because of the experience and Dean telling her that Jimmy's sacrifice allowed Castiel to save the world, forgives Castiel and warmly embraces him. She also keeps a stuffed animal he got her as a gift for her 18th birthday and asks Dean to look after Castiel, saying Castiel has been through enough.
===10.21 Dark Dynasty===
:"Well, what are the rules? If I'm gonna referee, I should at least know them."
Rowena and Charlie continue to work on decoding the Book of the Damned. Since Sam can't be around constantly to supervise them, he asks Castiel to take over. Castiel confides in Sam that he still believes that keeping this a secret from Dean is a bad idea, but Sam dismisses the concern, insisting that this is the only way to save Dean from the Mark of Cain.
Despite Castiel's best efforts to referee, Rowena and Charlie remain at odds and unable to cooperate. Castiel calls Sam for advice, but Dean answers Sam's phone instead. Castiel attempts to lie to cover up for Sam, but Dean doesn't buy it and still confronts Sam the next time he sees him. As tensions continue, Charlie threatens to leave in order to work on her own. Castiel calls Sam again for advice and again is dismissed. In an attempt to appease Charlie, Castiel takes Rowena into another room. However, Castiel then realizes that Charlie has already gone off on her own. Again, Castiel calls Sam, but by the time Sam and Dean find Charlie, she's already been killed by the Styne family.
===10.22 The Prisoner===
:"Maybe you could fight the Mark for years. Maybe centuries, like Cain did. But you cannot fight it forever. And when you finally turn, and you will turn... Sam, and everyone you know, everyone you love... they could be long dead. Everyone except me. I’m the one who will have to watch you murder the world. So if there’s even a small chance that we can save you, I won’t let you walk out of this room."
With the sad news of Charlie's death to deliver, Sam returns to the distillery where Castiel and Rowena are. He says that Dean is going after the Stynes for revenge, and also that he promised Dean they would stop trying to translate the Book of the Damned. Castiel decides to go after Dean while Sam watches Rowena and continues working on the book.
At the Styne estate, Castiel finds a gory scene of more than fifteen people brutally murdered. He calls Sam to let him know what Dean's done, and he concludes that Dean is headed back home to the Bunker. When Castiel arrives at the Bunker, he finds Dean there, along with more dead Stynes. Castiel tries to stop Dean from leaving, saying that he and Sam are still working on a cure, that Dean can't fight the Mark of Cain forever, and that it's only a matter of time before he loses control of himself completely. When Castiel physically stands in Dean's way, Dean attacks him. Castiel doesn't fight back as Dean pummels him bloody, takes Castiel's angel blade, and prepares to stab him with it. Castiel looks up and pleads with him. After a pause, Dean stabs a book next to Castiel's head with the blade, then turns and walks out of the room with the warning, "You and Sam stay the hell away from me. The next time, I won't miss."
===10.23 Brother's Keeper===
:"Everyone loves something."
Sam and Castiel are unable to find Dean but continue working with Rowena to find a cure for the Mark of Cain. Castiel is concerned about the possible consequences for removing the mark, but Sam combats that the consequences can't matter because there is no other way. Using Charlie's message, Rowena manages to crack Nadya's Codex and read the spell from the Book of the Damned. She bargains with Sam and Castiel for her freedom and the codex, which they reluctantly agree to since she's the only one who can read the spell.
The spell needs three ingredients, including a sacrifice of something that the caster loves, which Rowena claims is impossible because she doesn't love anything. Castiel argues that everyone loves something, then touches her forehead and reads her mind to find what that thing is. The answer is Oskar, a young boy that Rowena befriended hundreds of years ago. When Sam gets a phone call from Rudy with Dean's location, Sam goes after him, leaving Castiel to watch Rowena and ensure that she goes through with the spell.
Elsewhere, alone in a motel and suffering the effects of the Mark of Cain, Dean sees Castiel’s bloody face in a bathroom mirror, then Rudy whom he'd just killed. Dean punches the mirror and trashes the motel room. In order to get the ingredients they need, Castiel summons Crowley at a crossroads. Crowley initially refuses, but agrees on the condition that Castiel begs and calls him "King," which Castiel reluctantly does. Crowley then brings the spell ingredients (including Oskar) to Castiel and Rowena. Rowena hugs Oskar, only to stab him in the neck with a pen and collect his blood for the spell a moment later. The spell completed and free of her chains, Rowena immobilizes Castiel and Crowley, puts an attack dog spell on Castiel, then leaves with both the Book of the Damned and the codex. Castiel, bleeding from the eyes, raises his angel blade and lunges at Crowley.
===11.01 Out Of The Darkness, Into The Fire===
:"Brothers, sisters. I know I have no right, I have no standing to ask you anything, but these are desperate times so ask I must. I confess my transgressions, and I will accept whatever punishment you dole out, now I ask you to help me. Please, save me from doing worse."
Still under the effect of the attack dog spell, Castiel stabs Crowley, moments after Crowley has smoked out of his meatsuit. Castiel then escapes the distillery and attempts to hide on a farm, however the owners of the farm confront him, and Castiel runs to avoid killing them.
In the woods just outside the farm where police have gathered, Castiel prays to his angel brethren for help. He then calls Dean to make sure the spell worked and that he and Sam are okay. He tells them that Rowena escaped with both the Book of the Damned and Nadya's Codex. Sam asks about the Darkness, but Castiel answers that he doesn't know much about it. Two angels appear in answer to his prayer, and Castiel says goodbye to Dean, telling him that they may not see him for a while.
===11.02 Form And Void===
:"No. You don't understand. I'm cursed. You should run."
The angels Efram and Jonah who answered Castiel's prayer for help instead cuff him, tie him up, beat him, and interrogate him about Metatron's whereabouts. Castiel insists that he doesn't know where Metatron is, but the angels don't believe him. Hannah arrives to intervene and orders the other two away. Once they're alone, she asks Castiel where Sam and Dean are, so that they can fight the Darkness, which is causing alarms to go in Heaven. Castiel refuses and becomes suspicious of Hannah's questioning. He realizes that he's still being interrogated, and that Hannah's "rescue" is just a ploy.
Since their plan didn't work, Efram and Jonah use a headgear torture device to tap into what Castiel won't tell them. Castiel screams in pain and Hannah tells the other angels to stop. They turn on Hannah instead, and Castiel becomes enraged. He breaks out of the chair he's tied to, but he is too late and has to watch while Hannah is killed. Castiel kills both Efram and Jonah in his rage. Sometime later, Sam and Dean find Castiel on the floor of the Bunker, bloodied and weak.
===11.03 The Bad Seed===
:"What could 'Fortune Nookie' be?"
Castiel is seated in the Bunker, wrapped in a blanket in wrist and ankle cuffs that are chained to the floor. He's still looking worse for wear due to the effects of the attack dog spell. Sam and Dean are researching in an attempt to locate Amara. Sam suggests that God might be able to defeat her and Dean agrees that it's time God showed up to help. Castiel is bitterly pessimistic that it isn't going to happen. As Castiel is obviously suffering, Sam and Dean agree that foremost they need to find Rowena and remove the spell Castiel is under.
Dean tries calling Crowley in the hopes that he will help them find Rowena. However, Castiel doesn't believe that Crowley will help, since he tried to kill Crowley the last time they met. Sam researches the whereabouts of Cas' '78 Continental in an attempt to locate Metatron and offhandedly refers to the car as crappy, which Cas seems hurt by, and Dean attempts to reassure him. As they continue researching, Castiel collapses in a seizure-like fit. After Sam and Dean help him back up, Castiel says that he’s hearing voices: angel radio, as the angels are still looking for Metatron. The research takes another direction when Sam finds news of a strange incident in Denver involving three witches, and he and Dean head there in search of Rowena, leaving Castiel in the Bunker to continue the research.
In a failed attempt to track the car on a laptop in the Bunker, the porn site "Fortune Nookie" inexplicably opens up on the desktop. In confused frustration, he closes the laptop, and has a flashback to the day the spell was put on him, when he attempted to kill Crowley. Castiel leaves the Bunker. When Sam and Dean return with Amara held captive, they discover that Castiel is gone and go searching for him by following the GPS in his cell phone, bringing Rowena along with them.
After splitting up to cover more ground, Dean finds Castiel stalking and attempting to kill a woman in an empty warehouse. Dean convinces Castiel to let the woman go, but in doing so, Castiel turns on Dean and attacks him, beating him bloody. Sam and Rowena arrive, and holding a gun to Rowena, Sam forces her to remove the spell. Castiel collapses and wakes again as himself. Rowena uses the opportunity to escape. Back at the Bunker, Castiel offers to heal Dean's bruised and swollen face, but Dean refuses him on the grounds that he had it coming for almost killing Castiel when he was under the influence of the Mark of Cain.
===11.04 Baby===
:"Okay, fine. I'll say it. Maybe it is your so-called 'were-pyre,' but, to be honest, I have never heard of a creature with that name."
Sam and Dean are on the road in Oregon, working on a case. Castiel, still at the Bunker, calls to let them know he doesn't have any information on the case for them, but that he's working on it. The boys insist that Castiel rest and take care of himself instead of working, and that his only job right now is to heal. Sam offers his room at the bunker, which has Netflix, as a good distraction while Castiel is resting.
After splitting up, Castiel calls Dean again to let him know he's found a monster in the lore that might match what they're hunting. Dean coins the term "were-pyre," which confuses Castiel, who goes on to say the creature is actually called a "whisper." Castiel continues to talk on speaker while Dean meets with the local deputy. However, the deputy turns out to be a monster and attacks Dean. Castiel continues talking through the fight, eventually realizing that the monster they're hunting can't be a whisper and may, in fact, be a "were-pyre." Dean attempts to shoot the deputy with silver bullets and Castiel is alarmed by the sound of gunshots. Eventually, Dean manages to decapitate the monster and store the head in the Impala's cooler while explaining to Castiel what happened. He sends Castiel a picture of the monster's teeth after the call ends, and Dean leaves to get Sam while Castiel continues researching.
Castiel calls Dean again while Dean, Sam, and a supposed victim of the monster are driving away from where Sam was also attacked. Castiel explains that the monster they're hunting is a nachzehrer, which Dean renames a "ghoul-pyre." The only way to kill one, according to the lore Castiel's found, is to place a copper coin in the monster's mouth and decapitating it. The call ends. After multiple attacks and extensive damage to the Impala, Sam and Dean manage to find and kill the alpha nachzehrer, saving the other townspeople who had been affected. On the return home to the bunker, Dean tells Sam that Castiel will heal his injuries, and Sam agrees on the condition that Dean lets Castiel heal him this time, also.
===11.06 Our Little World===
:"You were right, Metatron. I am sick of having my strings pulled, which is why I won't let you manipulate me into letting you off easy. Tell me about the Darkness."
Over the last few weeks, Castiel has been binging on Netflix. While Sam and Dean are out looking for Amara, Sam tells Dean that they should get Castiel involved. Dean agrees and calls, only to learn that Castiel has no new information and has downgraded his TV-watching from shows like Game of Thrones to reruns of The Jenny Jones Show. Dean insists that Castiel shut off the TV and get outside for a while.
After the call ends, Castiel dons his trench coat and attempts to leave the bunker, but pauses at the exit, flashing back to beating Dean in the warehouse, being tortured by angels, attempting to kill Crowley, and Dean beating him while he under the influence of the Mark of Cain. After some hesitation, Castiel returns to Sam's room and resumes watching TV. He flips to a news channel, where he notices Metatron's reflection and realizes that Metatron had taken the footage. With this new lead, Castiel leaves the bunker to go after him.
He finds Metatron filming a dying man, and while Metatron cheerfully explains that he can't help, Castiel arrives and heals the man instead. He confronts Metatron and tosses the camera away, then leads Metatron to a nearby warehouse so that the police can take care of the victim in the alley. They argue over Castiel and Metatron's choices when they'd both had to live as humans without their grace. Castiel dismisses it, saying he's here for something else. Metatron assumes it's the demon tablet when Castiel reveals that he already has it. Instead, he physically shoves Metatron while questioning him on information about the Darkness, and Metatron fires back that Castiel, these days, is too afraid to hit him. Castiel punches him in response and answers, "It's not fear."
While Castiel continues to press for information on the Darkness, Metatron taunts Castiel for being used by everyone he trusts, and that he was never the same even after getting his grace back. While Castiel beats Metatron blood, Metatron begs Castiel to kill him, but Castiel refuses, countering that Metatron isn't as happy being human as he'd claimed. Metatron admits that he's miserable, and Castiel admits that he's been manipulated but that he won't be any more. Finally, Metatron tells Castiel what he knows about the Darkness: that she's God's sister whom God sacrificed to make the world.
Later, Sam, Dean, and Castiel have all returned to the bunker and are discuss Metatron and Amara. Dean gives Castiel a hard time about letting Metatron go, but Castiel assures him that Metatron as a human is not a threat. Castiel then counters by asking Dean why he couldn't land a hit on Amara. Dean insists that she overpowered him, but Castiel and Sam look unconvinced.
===11.10 The Devil In The Details===
:"I never wanted this, you know. To be hated by my own kind, I never..."
Dean is driving towards the site where an angel smiting took place to see if they managed to kill Amara or if she's still alive. On the way, he calls Sam and Crowley but only gets their voicemail. As he gets closer to the site, he begins to get dizzy. He pulls over to the side of the road and throws up. Castiel arrives, and after a brief examination, tells Dean that he has smiting sickness, and that he cannot go to the site as the symptoms will become worse, then lead to his death. Instead, Castiel offers to go in alone (as angels are not affected) while Dean agrees to leave and check on Sam.
While Castiel is looking for Amara, he runs into Ambriel, an angel who was sent from Heaven to confirm that the Darkness has been defeated. As they’re searching together, Ambriel remarks that she and Castiel are alike in that they're both expendable. "You help," she says, "but Sam and Dean Winchester are the real heroes." Castiel and Ambriel briefly separate in their searching, and Ambriel comes across Amara’s body lying on the ground. By the time Castiel catches up with her, Amara is already sucking the grace out of Ambriel. After Ambriel falls to the ground dead, Amara re-absorbs all the darkness clouding the forest, revealing the natural daylight. Castiel tries to kill Amara with his angel blade but is easily overwhelmed. Amara insults him, saying she can smell "fear and self-loathing" on him and that she has no idea why God took a special interest in him. She says she has a job for Castiel and puts her hand to his chest, causing him to disappear in a flash of bright light. Sometime later, Castiel stumbles into Hell after Dean and tells him that Amara is alive and sends a message: the words "I AM COMING" burned into Castiel's chest.
Sam is battling Lucifer in Hell while Rowena, under the power of a witchcatcher and Crowley and Dean's orders, works on a spell to send Lucifer back to the Cage. However, when Sam begins screaming louder, Dean and Castiel rush in to defend him for the remaining minutes the spell takes. During the fighting, Lucifer tells Castiel that he is the only one who can defeat the Darkness. When confronted again, Castiel secretly agrees to possession of his vessel in order to defeat Amara. Lucifer disappears, and in Castiel's vessel, he pretends to still be Castiel until Sam and Dean have driven off (and will continue pretending to be Castiel around them for the duration of the next four episodes). He then reveals himself as Lucifer to Rowena and Crowley. After confirming with Rowena that she is the only one who can open Lucifer's Cage, he snaps her neck and imprisons Crowley.
It's later revealed that, despite Lucifer having control of his vessel, Castiel is still inside also and aware of what Lucifer is doing but unable to control it, similar to when Lucifer possessed Sam.
===11.14 The Vessel===
:"I wanted to be of service to the fight. And only Lucifer can beat her."
In looking for a way to stop Amara, Sam and Dean discover an object referred to as the Hand of God by the Nazis. Still masquerading as Castiel, Lucifer offers to take Dean into the past to retrieve it for himself. However, Lucifer's plan fails as the submarine it's on is warded against angels, and only Dean is able to make it on board. While Dean works on retrieving it alone in the past, in the present, Sam and Lucifer work on a method to get him back to Dean and through the ship's warding. Sam discovers a spell that would work, but only an archangel could accomplish it. Lucifer suggests they try it anyway, but Sam says there's no point.
Lucifer gathers the ingredients on his own and begins the spell, and Sam offers to let Lucifer, believe he's Castiel, tap into the power of his soul so that he'll be strong enough to accomplish the spell, even though doing so is incredibly dangerous and could kill him. Unable to keep his disguise any longer, Lucifer laughs. He reveals himself to Sam and threatens to kill Sam on the grounds that Sam volunteered, and that "Castiel" will explain to Dean that he was unable to talk Sam out of it.
As Lucifer taps into Sam's soul, in an attempt to kill him, Castiel manages to regain control of the vessel top save Sam. He explains to Sam why he said "yes" to Lucifer (to defeat the Darkness) and that he can't eject Lucifer as it's taking all of his strength just to keep Lucifer from killing Sam. He also reveals that they need Lucifer to rescue Dean from the past, as Castiel can't time travel since the angels fell while Lucifer, being an archangel still can. Castiel manages to wrestle Lucifer back and completes the spell, allowing Lucifer to travel back to the past and rescuing Dean.
Back in the present, Sam reveals to Dean that "Castiel" is actually Lucifer. Lucifer attempts to use the Hand of God, but since it was already used in the past, it's worthless and will not activate. Angered, he attacks Dean and throws him against a wall, but Sam manages to draw an angel banishing sigil that blasts Lucifer out of the Bunker. Sometime after Lucifer is banished, Dean tells Sam that they will trap Lucifer and free Castiel from his control. Sam counters that Castiel may not come back willingly, as he allowed Lucifer to possess him in the first place. Dean stubbornly insists that he will.
===11.18 Hell's Angel===
:"Guys, you're gonna break something."
Sam, Dean and Crowley enact a plan to remove Lucifer from Castiel's vessel by trapping him with warding and holy fire and implementing the angel suppressing sigil to allow for Cas to gain control and expel Lucifer. While the sigil works, Lucifer is too strong, only allowing Castiel to gain control for a moment. Short on time, a frustrated Crowley exits his meatsuit and enters Castiel's vessel. He finds Cas deep in his subconscious, watching television in the Men of Letters Bunker kitchen. Telling Crowley he comes there to pass the time, as for some reason he gets good reception in there. When Crowley questions what Lucifer has done to him, Castiel tells him that Lucifer mostly leaves him alone and lets him just wait for the battle with Amara. Crowley attempts to talk Castiel into ejecting Lucifer, but Castiel remains aloof. When Lucifer shows up and begins throwing Crowley around, Castiel is simply annoyed by the disturbance and continues watching television.
===11.22 We Happy Few===
:"You know, every second I've spent subordinating myself to Lucifer, it's been a torment. It's destroying me; it's burning through my vessel. But I would do it all over again. Because through me, he and God, they will defeat the Darkness. That's my role in this fight. It's God's fight. You can play a part in that fight too, if you join me."
In an attempt to convince the angels to help them battle the Darkness, Lucifer gives Castiel control again to speak with them. Castiel attempts to convince the angels, but they refuse to hear him out due to his possession by Lucifer. Castiel tells the angels that every second he subordinates himself to Lucifer is a torment, and that it's destroying him and burning through his vessel, but that he would do it all over again because through him, Lucifer and God will defeat the Darkness. Castiel feels that his role in the fight is as Lucifer's vessel, and it's Lucifer and God's fight, which the angels could play a role in if they join him.
Though they initially refuse, Castiel is eventually able to successfully convince the angels to join the army with the demons and the witches, and they attack Amara together as a burst of light from the sky, weakening her. Later on in the fight, Amara pulls Lucifer from Castiel's body in a flash of sparks and white light, leaving Castiel unconscious.
===11.23 Alpha And Omega===
:"They know -- they know God is dying and they don't think we can win this. Souls or no souls. They're sealing Heaven, and they're 'dying with dignity.'"
Checking on Lucifer after the fight with Amara, Dean is surprised but pleased when it turns out to be Castiel and not the archangel. Castiel tells the others that Lucifer is gone and he's not sure what happened to him before they are teleported back to the bunker.
With the attack on Amara failed and Chuck dying, the group reconvenes at the bunker and attempts to come up with another plan of attack. Believing there is no hope left, Dean is resigned to failure and opts to make a beer run instead. Castiel goes with him, and on the drive, he confesses to Dean that he feels stupid for having believed Lucifer would be able to stop Amara. Dean reassures him that he was right to try what was the best option at the time. He goes on to say, "You're always there, you know? You're the best friend we've ever had. You're our brother, Cas. I want you to know that." Castiel thanks him, Sam calls with news of a new plan, and Dean and Castiel head back to the bunker to hear it.
The new plan is using light to destroy Amara, which Chuck says is possible, but would take more power than he has in his weakened state. Castiel recommends using souls and offers to ask the angels for souls from Heaven while Sam and Dean hunt ghosts and Crowley checks on his personal stash. When they all return to the bunker, Castiel reluctantly admits that the angels had refused. "They know God is dying and they don't think we can win this, souls or no souls. They're sealing Heaven, and they're 'dying with dignity.'" Moments later, the reaper Billie arrives and offers to help, gathering the needed souls from the Veil while the group watches on. Rowena then uses the souls to make Dean into a bomb. In the hour he has before the planned attack, Dean visits the grave where Mary Winchester is buried and says his goodbyes. Castiel hugs Dean, then offers to go with him to face Amara. Dean refuses and asks Castiel to look out for Sam after he's gone, which Castiel agrees to. Once Dean is sent on his mission, Sam takes the Impala, along with Castiel, Crowley, Rowena, and Chuck to a pub where they wait out the result.
Minutes later, Chuck disappears, and the group heads outside to the see the sun reappearing. Believing Dean to have died in the blast, Sam and Castiel return to the bunker. As they walk inside, Castiel reaffirms that he's here for Sam, if Sam wants to talk... Until he's suddenly blasted out of the bunker by an angel banishing sigil drawn by Lady Antonia Bevell.
===12.01 Keep Calm And Carry On===
:"No, I don't have a harp."
Like a comet, Castiel comes crashing to the earth, barrelling through a billboard. A man driving by stops his truck to investigate and is shocked to see Castiel emerge from the crater. He questions the man how far from Lebanon, Kansas, he is and upon being told he is three hours away, Castiel renders the man unconscious and steals his truck.
Arriving back at the Bunker, he is met by the newly resurrected Mary Winchester, who holds him at gun point, Dean, hearing the commotion, defuses the situation and tells Mary that Castiel is a friend. Cas, surprised that Dean is alive, steps forward and embraces him. When Mary questions if Cas is a hunter, Dean tells her he is an angel and introduces them. When Dean questions where Sam is, Castiel tells him of Lady Bevell being in the Bunker when they arrived back and sending him away. When Dean gets a possible lead on the traffic cams, the trio load into the Impala and go on the search for Sam.
They soon find themselves at a garage, where Castiel questions Lady Bevell's driver, headbutting him until he gives up some information. This leads them to a veterinary clinic. When Cas notices the doctor arrive, the three go to confront him. When an angry Castiel starts towards the doctor, Dean persuades him not to hurt the guy, yet. After getting Lady Bevell's number, the trio head back towards the Bunker to put a trace on the cell, when they are suddenly sideswiped. Castiel checks on Mary, noting to Dean she is only unconscious. As Cas and Dean step out of the Impala, they are met by Ms. Watt. As a fight ensues, Ms. Watt is able to get the best of both Dean and Castiel with the aid of Enochian brass knuckles. As she is about to kill Dean, she is killed by Mary with Castiel's angel blade.
Castiel goes on to hide Ms. Watt's body in her car and he and Dean push it off into some bushes, concealing it.
===12.02 Mamma Mia===
:"Don't make things needlessly complicated, as you humans tend to do. I'll call you."
Outside Aldrich, Missouri, Castiel speaks with Dean on the phone, telling him he has checked everywhere and hasn't found a sign of Sam. Dean tells Cas to check real estate offices for anyone that has rented or bought any places recently. Castiel agrees and tells Dean he will contact him in the morning. Before he hangs up, Dean asks Cas advice about Mary; Castiel simply tells him not to overcomplicate things, as humans tend to do so often, and hangs up.
The next day, Castiel calls Dean, telling him he thinks he may have found Sam's location, a farm house rented by an English woman two weeks prior. He remarks that it is powerfully warded and texts Dean the address. When Dean and Mary arrive, Castiel tells them the warding is preventing him from entering the house, and he waits with Mary as Dean goes to investigate.
After Dean and Mary get the upper hand on Lady Bevell, Castiel enters the farm house with Mick Davies, who has powered down the warding. Mick explains who he is and that Lady Bevell was a rogue operator, handing his card to Castiel before leaving.
===12.03 The Foundry===
:"Hello. I'm Agent Beyoncé, and this is my, um... my partner, Agent Zee. Um, we wanted to ask you a few questions about your bro..."
While Mary sits alone in the Bunker library, looking over John's Journal, a concerned Castiel walks over to her. When she asks him why he's awake, he tells her angels don't require sleep. Mary goes on to question him about where he felt like he belonged after leaving Heaven. Castiel tells her that he's not sure that he does belong, but assures Mary that she does belong here.
In the morning, Castiel enters the kitchen and tells Sam and Dean that he is going to be leaving. He tells them he plans on going to Cleveland, Ohio, where he believes he has found a lead on Lucifer's whereabouts. When Dean tells him they should all check it out, Castiel replies that Lucifer being free is his fault, and it is his duty, and his alone to fix it. He agrees that if it is Lucifer, he will call them, remarking that they are needed more where they are, before leaving.
In a hotel lobby, Castiel questions Tommy, a drummer and a friend of Vince Vincente. Tommy relates to Castiel his encounter with Vince, who had unbeknownst to Tommy been possessed by Lucifer. Castiel tells Tommy that if he hears from Vince again to call him, giving him his card before he leaves. Walking past the hotel bar, he is stopped by Crowley. As they walk back to his truck, Crowley attempts to talk Castiel into teaming up with him to track Lucifer, remarking that it is fate that they are following the same leads. Castiel is still not interested, but he changes his mind when Crowley produces postcards from Vince's sister Wendy and the two head off on the new lead together.
Castiel and Crowley get out of the truck in front of Wendy's house. Castiel uses the side mirror to check and fix his hair, while Crowley stands and waits impatiently for him. They knock on Wendy's door, only to have Wendy slam it right back into Castiel's face. After Crowley materializes in the house and lets Castiel in, Castiel notices that Wendy has been recently healed. With that information Crowley threatens to reverse it, but is stopped by Castiel. He tells Wendy they don't want to hurt Vince. When she tells them she last saw him leave with some groupie, a redhead, Cas and Crowley soon realize the "groupie" is Rowena. Walking out of Wendy's house, an angry Castiel sarcastically tells Crowley all he wants to do is save his mother, but Crowley corrects him by telling him that Rowena is a powerful witch and the only one capable of sending Lucifer back to the Cage. Not liking the options, Castiel is realizes Crowley is right.
Arriving at Vince's cabin, they are searching the house for any signs of Lucifer when they hear Rowena's voice and find her enjoying a drink on the porch. Castiel is able to talk Rowena into helping them send Lucifer back to the Cage once they capture him.
===12.07 Rock Never Dies===
:"He said he'd meet us here. Frankly, I appreciate the break. It's been weeks, and he's been right there, just talking and talking and talking. It's relentless."
Sitting at a bar with Crowley, Castiel places a call to Dean, telling him to watch the news. When Dean asks Cas if Vince Vincente is Lucifer, Castiel only tells him they don't know, before Crowley snatches the phone from him. Castiel goes on to theorize that Lucifer may have found a way to heal his vessel, prompting Crowley to teleport to Vince Vincente's location, Los Angeles, leaving Castiel behind.
In Los Angeles, Castiel meets up with Sam and Dean at Vince Vincente's hotel, remarking he is happy for the break from Crowley, who soon arrives. The four head to Vince's hotel room to find any leads; they only find a human tooth, pulled from its root, in Vince's bathroom sink. The four soon learn of Roseleen Greenfield cutting herself for Vince/Lucifer and head to the hospital, where Castiel is told by the Winchesters to wait with Crowley while they question Greenfield. Learning that Lucifer will be putting on a secret concert with the reunited Ladyheart, Castiel ask Crowley if Rowena will be ready to send Lucifer back. The four split up to find the location of the concert, with Cas seeking out Tommy and urging him to reveal the concert location, telling Tommy he knows that Vince is not himself, but Tommy refuses. Dejected, Cas joins back up with Sam, Dean, and Crowley at the hotel lobby. Later that night, Tommy appears to have a change of heart and texts Castiel the address for the concert venue. Arriving at the show, Castiel attempts to contact Tommy, to no avail. Deciding to head inside, Castiel takes a pair of Enochian handcuffs and tells everyone he will deal with Lucifer while Sam and Dean clear the venue. Crowley, to everyone's shock, offers to help Castiel and give him more time against Lucifer.
Backstage in the green room, as Lucifer is about to kill Tommy, Castiel stops him. But Lucifer is able to easily knock Castiel aside, before turning his focus on Crowley. As Castiel attempts to get back to his feet and attack, Lucifer tells him to "stick around for the after party" before heading out on stage. While Sam and Dean clear the room of people, Lucifer tries to prevent Sam from holding the doors open. After the crowd has escaped, he is able to slam the doors shut, trapping Sam and Dean with him. Suddenly, Castiel appears on the stage and attacks Lucifer by smashing his face with a guitar. Castiel is easily deflected. Dean takes the stage and places the binding handcuffs on Lucifer. Lucifer simply throws Dean off the stage and shrugs the cuffs off. Castiel tries to stab Lucifer with an angel blade, but he stops him. Realizing Vince's body is wearing thin, Lucifer makes his escape.
Sam, Castiel, and Crowley are standing outside the car waiting for Dean to close the trunk. With the realization that Lucifer has gone "big" by possessing Vince Vincente, Castiel remarks that Lucifer will soon go "bigger."
===12.08 LOTUS===
:"The thing inside you, it's unholy. It's an abomination."
Learning of the sudden death of billionaire philanthropist Wallace Parker, Sam and Dean arrive at a morgue, only to find Castiel and Crowley already examining the body. Castiel and Crowley reveal that Lucifer has moved on from random vessels and will be seeking out everyone from celebrities to captains of industry in search of a suitable vessel.
After Sam and Dean investigate the archbishop of St. Louis being Lucifer's new vessel, Sam and Cas are in the Bunker library as Cas looks over the photos of Lucifer's carnage, remarking that the level of violence was utterly unnecessary. Later while Castiel is looking over a newspaper in the library, he notices that the Bunker's warding has been powered down; Crowley soon appears to reveal that he has located Lucifer's newest vessel, President Jefferson Rooney. While formulating a plan, Castiel remarks that even if Crowley can bring Rowena, Lucifer is still anchored to earth by being in a vessel.
Castiel is walking across the war room with two cups of coffee. His hands start shaking and his vision goes blurry causing him to drop the cups. He grabs his head with one hand, the other leaning on a chair for support. As Sam and Dean come to his aid, Castiel tells them that there has been a surge in celestial energy, revealing that a Nephilim has come into being.
On the road to Indianapolis, Sam, Dean, and Castiel are stopped by the Secret Service. As Sam and Dean are being held at gunpoint, Castiel exits the Impala, averting Agent Rick Sanchez's attention to him, but Cas is quickly stopped by Dean from doing anything. As they are standing there, the men turn to watch a black car approach the group. A man exits the limousine and shoots a grenade at the SUV. Everyone ducks for cover except Cas, who just stands there looking quizzically as the SUV blows up into flames. The man tells Castiel to wipe the memories of the agents and introduces himself as Arthur Ketch. Sometime later in a forest, Ketch formally introduces himself to the trio, asking Castiel to sense if he is lying to them. Castiel reveals that he can't detect any lies, but that the truth can be "situational."
At a motel room, Crowley materializes with Kelly Kline, after learning that the president is actually Lucifer. Castiel reveals to her that her child is an abomination. He opens a nightstand drawer and pulls out a Bible and tells Kelly to put her hand on it; her handprint is seared into the cover of the Bible and erupts in flames. Dean brings over a trash can and pitcher of water and Cas drops the Bible into it. Dean pours the water onto the Bible to douse the flames. Convinced, she calls President Rooney and asks him to meet her at the motel. As the Secret Service search the room, one agent opens a closet and finds Castiel standing there. Cas places two fingers on the guard’s temple and tells him that no one is in the room other than Kelly.
As Lucifer is ejected from President Rooney with the Hyperbolic Pulse Generator, a stream of white light streams out of Rooney’s mouth, swirls around the motel room, and disappears down a heating vent. The room goes quiet. With Lucifer out of his body President Rooney collapses to the floor. Castiel goes to him, ensuring that he is alive and won't remember a thing. Sam has Castiel get Kelly out of there; Castiel and Kelly leave out a back door as the Secret Service agents enter the motel room and arrest Sam and Dean.
At a diner, Kelly excuses herself to the bathroom, and unbeknownst to Castiel she sneaks out the back. Castiel starts to get nervous and stands outside the restroom door asking if Kelly is alright. As Castiel opens the restroom door his cell phone rings. Kelly reveals that she can't get rid of the child. Castiel tries to plead with her, telling her it is not a baby, but the spawn of Lucifer. Kelly tells him it's her child and hangs up. Castiel runs out of the diner desperately looking for her.
===12.09 First Blood===
:"I saw it on the news and I thought, that’s the sort of thing Sam and Dean would investigate. They would roll into town, save the day, kill the monsters. But with them gone... I tried to work the case. I tried. But... I don’t know what I did wrong. I... I asked questions, but maybe they were the wrong people, or the wrong questions, and I just-- I never found it. Never found the monster. Never even got close. And three more women died before I left town. Before I ran away."
Castiel, standing outside the motel after Sam and Dean have been arrested, places a call to Mary, telling her he needs to meet her at the Bunker. In the war room, Mary berates Castiel for leaving Sam and Dean behind. He tells her Dean told him to take Kelly out of the room, only for Mary to tell him to stop making excuses.
At a bar, Cas meets with Crowley and pleads with him to use his connections in the government to find Sam and Dean. Crowley tells Castiel he can't help, assuring him he isn't worried about Sam and Dean's fate as they always come out on top. Crowley gets up, pats Cas on the shoulder in a strangely reassuring fashion, and leaves Cas glaring after him. At another bar, Castiel meets with Mary and the two commiserate over their dead ends in finding Sam and Dean, with Castiel telling Mary of his failed attempt at going on a hunt solo in Missouri.
Sometime later Castiel receives a call from Mary, telling him she is dealing with monster in Missouri and not to worry. Soon after Castiel receives a call from Dean and learns that they are in Rocky Mountain National Park in Colorado. He takes this information to Mary and she quickly arrives to pick Cas up. Thinking they may need backup, Cas suggests Crowley and Rowena, which Mary scoffs at, before taking Mary to meet with Mick Davies and Arthur Ketch. When Mary is skeptical of using their help, Cas tells her that they did successfully help them defeat Lucifer. Castiel tells them that Dean told him to meet them off State Route 34, with this information Mick has the BMOL tech guys place a satellite over the area.
Later that night, Dean and Sam come crashing out from some underbrush to meet Cas, who’s standing in a clearing waiting for them. Sam stumbles past Dean and grabs Cas into a hug. Only then does Sam notice Mary standing a short distance away. Sam runs over to hug Mary, while Dean steps up to hug Cas, before moving on to Mary. After Mick and Ketch depart, the reaper, Billie, arrives and reveals that Sam and Dean made a deal to facilitate their escape, the cost of which was that at midnight, a Winchester would have to die, and breaking the deal would come with consequences on a cosmic scale. Mary offers herself up, which Billie agrees to. As Mary places a gun to her temple, Billie is suddenly stabbed with an angel blade by Castiel, killing her. Shocked, Dean asks what Cas has done. Castiel tells them that the world needs the Winchesters, every last one, and he wasn't going to let them sacrifice themselves over a stupid deal.
===12.10 Lily Sunder Has Some Regrets===
:"If I plan to do anything else stupid, I'll let you know."
At the Bunker, Sam and Dean discuss Castiel killing Billie. Cas arrives and tells the Winchesters that he did the right thing and that when the consequences come he will deal with them, before taking his leave to seek out an old angel friend that called to him for help. Sam and Dean tag along, and during the car trip Castiel reveals that his friend, Benjamin, wouldn't call out for help lightly, let alone put himself or his vessel in any sort of danger. When they arrive at the bar, Cas orders the bartender to leave, and while investigating Dean finds an angel blade which Castiel realizes isn't Benjamin's. Suddenly Castiel gets a message through angel radio from his old commander, Ishim, telling Castiel to meet him at a diner. Later that night, Cas, Sam, and Dean arrive at the Wright Stop Diner. Cas tells the Winchesters to wait outside while he speaks with Ishim, as Ishim has a dislike of humans. Inside Castiel sits with Ishim and Mirabel, and learns from Ishim that since the angel fall two other members of their flight were killed. Sam and Dean soon join the angels at the booth, as Mirabel excuses herself. Ishim then suggests the five of them meet at a safe house nearby. Castiel gets up out of the booth and finds Ishim in battle with Lily Sunder. As Castiel slashes Lily's side, he has a sudden memory of her from a past incident; he is soon kicked away by Lily who floods the area with a blinding light before escaping.
At Ishim's safe house, Castiel tends to his Ishim's wounds from the fight, and describes to Sam and Dean how he knows Lily Sunder. In 1901, Ishim led a flight that included Castiel, Mirabel. and Benjamin to Orono, Maine. to deal with the birth of a Nephilim child. When they arrived at Lily Sunder's home, an angel, Akobel confronted the others, but was subdued. Castiel read Akobel his crime of fathering a Nephilim, and the penalty -- death. Sam and Dean suggest they go and talk with Lily while Castiel remains behind to tend to Ishim. Ishim begins questioning how Castiel could let humans speak to him the way the Winchesters do. Cas tells him that his friendship with them has made him stronger as finishes healing Ishim, which weakens Cas. Dean soon arrives at the church, telling him that Ishim didn't kill a Nephilim, but a human child out of jealousy due to Lily spurning his advances. Castiel questions Ishim, who becomes defensive. Dean pulls out an angel blade and rushes Ishim, but he is tossed back against a wall. Castiel throws a punch but it’s blocked. Ishim proceeds to punch Castiel who falls to the ground. Ishim grabs Castiel by the collar and continues punching him. When Dean threatens to use a banishing sigil, Ishim reminds him that Castiel would be sent away too, and in his weakened state, may not survive the banishment. Lily and Sam next arrive, and a fight ensues between Lily and Ishim. As Ishim is about to stab Lily with an angel blade, Castiel rises to his feet and drives a blade through Ishim's back, killing him. Castiel apologizes to Lily for his role in her daughter's death; he tells her his ignorance is no excuse and that if she finds she can't forgive, he will be waiting for her, before leaving with Sam and Dean.
At the Bunker, Dean hands Castiel a beer and he tells the brothers that he doesn't regret killing Billie to save them, even if it costs him his life. Dean switches the conversation to Kelly Kline and her child, asking Castiel if he is certain it is a Nephilim. Cas tells them that an ordinary Nephilim is one of the most powerful creatures in creation, and that one that has been sired by an archangel will have unimaginable power. Sam ask Cas if, when the time comes, he will be able to kill Kelly and the child. Castiel tells him at one time he wouldn't have hesitated, but now he is not sure. He tells Sam and Dean, "Let's drink, and hope we can find a better way."
===12.12 Stuck in the Middle (With You)===
:"No, you listen to me. You -- Look, thank you. Thank you. Knowing you, it... it’s been the best part of my life. And the things that... the things we’ve shared together, they have changed me. You’re my family. I love you. I love all of you. Just please... please, don’t make my last moments be spent watching you die. Just run. Save yourselves. And I will hold Ramiel off as long as I can."
Castiel meets up with Sam, Dean, Mary, and Wally to help them on a demon hunt given to Mary by the British Men of Letters. They get lunch in a diner where the waitress, Mandy, hits on Cas. Dean and Wally try to give him advice, but they are shut down by Mary. They discuss the case during their time in the diner and plan their attack. When they arrive at the lake house where their target lives, Cas recognizes that the house is not warded. They prepare while Cas and Wally keep watch, but Mary sneaks into the basement in the meantime to steal something from the demon. Castiel re-enters the house and notices Mary coming out of the basement, which she passes off as going to the bathroom. When the demon arrives, Dean fires at him with devil's trap bullets and Sam stabs him with Ruby's knife, but both are ineffective. When the demon notices Castiel, he barrels after him and knocks him onto the kitchen counter. The demon flashes his yellow eyes at Mary, but Cas attacks him and is thrown out the window. The demon summons a silver-tipped spear and stabs Castiel in the side. As he continues to pace towards him, the demon is run over by Mary with Wally's van. She takes Castiel to safety in an abandoned barn where he tells her that he can't heal himself before passing out.
Sam and Dean arrive after a run-in with a pair of demons following their target's arrival in which Wally was killed. Mary tells Sam about the target's yellow eyes, Dean heads over to Cas who tells him that he might be dying. Dean calls Sam and Mary over as Crowley appears and berates them about disturbing that demon. Crowley and Castiel explain that the demon is Ramiel, the Prince of Hell, one of the oldest demons created by Lucifer after Lilith, made with yellow eyes and trained to become a general like Azazel. They explain what happened and Crowley tells them that the weapon Ramiel used was the Lance of Michael which he gave Ramiel six years ago after Lucifer's defeat. Crowley tells them that they can't save Cas, but Dean tells him to either help them or leave, so he leaves.
When Castiel notices that his condition is getting worse, he tells the others to leave before Ramiel can get to them. He thanks them for everything they went through together and tells them that they changed him for the better. He expresses his love for the three of them, considering them his family. He tells them not to let him watch them die and to keep fighting, but they refuse to leave him behind, stating that they are fighting for Castiel because he's their family. They prepare for Ramiel's arrival with angel blades, holy oil, and Enochian brass knuckles. Ramiel is approached by Crowley who offers to make him a deal in exchange for leaving them alone, but Ramiel sends Crowley flying through the barn door. As Ramiel steps into the barn behind him, Dean lights the holy oil and they demand that he tell them how to save Cas, but Ramiel says there is no cure. He tells them that all he wanted was to be left alone, and accuses them of stealing from him. He gives them thirty seconds to return what they stole from him or he'll kill them and reclaim it himself. They look on as the thirty seconds run out and Ramiel uses the Lance of Michael to extinguish the holy fire. They all attack Ramiel and the ensuing battle ends with Sam taking the Lance and stabbing Ramiel in the heart, killing him. Castiel grunts in pain as he starts to succumb to his wound. Crowley retrieves the Lance and remembers that its magic comes from its runework and craftsmanship. He snaps the Lance in two and its destruction saves Castiel's life.
When Castiel asks what Ramiel meant about someone stealing from him, Dean passes it off as they leave, taking the broken pieces of the Lance of Michael with them. Later when Mary gives Mr. Ketch the Colt, she berates him for sending her after Ramiel without telling her who he was. She tells him that she lost Wally and almost lost Castiel and she threatens to destroy the British Men of Letters if that ever happens again. After a few seconds of silence, Ketch admits that they made a mistake and apologizes.
===12.15 Somewhere Between Heaven And Hell===
:"I don't believe I'm welcome in Heaven."
After reading a tabloid article depicting the aftermath of Dagon's confrontation with two angels for Kelly Kline, Castiel enters a diner and flashes his FBI credentials, asking for the manager. The manager, Herb Nelson, introduces himself and takes Cas to his back office. When Herb starts talking of reptilian aliens being behind the death of one his waitresses, Castiel believes him to be crazy and is about to take his leave until Herb shows him video footage depicting Dagon killing the two angels, noting her yellow eyes. Cas ejects the tape and pockets it, and heads toward the door. As Castiel is walking back to his truck, he is met by an angel, Kelvin, who tells him he is also searching for Kelly Kline and that they should help each other out.
Meeting at a bar, Castiel asks Kelvin how things are in Heaven. Kelvin tells Cas it is "functional" and that the impending Nephilim birth has brought all the angels together. He tells Castiel he is there to recruit him. Cas tells Kelvin he doesn't think he would be welcome in Heaven, but Kelvin retorts that all things can be forgiven if he helps Heaven track down Kelly Kline. He reveals that the offer comes from Joshua.
Later, Castiel places a call to Sam and Dean to inform him that Kelly is now with Dagon, telling them the only thing that is known of her is her penchant for psychotic savagery and that Kelly's last known location was Coeur d’Alene, Idaho, before hanging up and leaving with Kelvin.
===12.19 The Future===
:"No it isn't. I used to believe in a plan. I used to believe I had some mission. But I've been through enough now to know that everyone is just winging it. Some of us quite badly. Lucifer, he's just breaking toys. He's sowing destruction and chaos and there is no grand purpose at work. And there is no special role for you. When Lucifer took over Rooney's body, you were just there."
Castiel arrives at the Bunker. Immediately Sam and Dean ask where he has been and why he hasn't answered their calls. Castiel tells them that he has been in Heaven, working with the angels to try and track Dagon and Kelly Kline. An angry Dean lays into Cas for ignoring and ditching them when they had a shot at Dagon. Castiel attempts to apologize, but Dean walks away, sarcastically telling him "welcome back." Cas stops by Dean's room under the pretense of returning a mix tape Dean had given him; Dean tells him it was a gift and to keep it. Castiel explains his reasoning for going off on his own, telling Dean he needed a win for himself after everything that has happened in the past year and his failures. Dean tells him they will find Kelly together and find a better way to deal with the Nephilim than killing it. Later Dean goes to check on Cas only to find he is gone; he realizes Castiel only came to his room to get the Colt.
Outside on a quiet neighborhood street, Castiel exits his truck and meets with Kelvin and another angel named Hozai. He confirms to Kelvin that he has the Colt, but that there were only two bullets in the chamber. Kelvin assures him it will be enough as they only need one for Dagon and one for Kelly. The trio of angels break into Dagon's safe house. Castiel sneaks through the house and approaches behind Dagon's chair. He comes around to the front of the chair, bringing the Colt to bear, only to find the chair empty. Dagon appears behind Castiel; he turns around fires the Colt, but Dagon teleports away causing him to miss. Kelvin tells Castiel to go find Kelly as Dagon kills Hozai and engages in a fight with Kelvin. Castiel checks the basement, gun cocked; he finds Kelly who is surprised to see him. Dagon drops unconscious Kelvin and runs down to the basement, but finds Castiel and Kelly are gone.
In Castiel's truck, he and Kelly drive down an empty road. Kelly thanks Castiel for not killing her, but Castiel tells her not to thank him as he had a mission and failed and now doesn't know what to do other than get as much distance between Kelly and Dagon as he can. In the morning, Castiel is pacing outside of his truck in a motel parking lot. He climbs back into the truck and tells Kelly he had been communicating with Joshua, and the new plan is to take her to the Gate to Heaven, where her and her child's death will be swift and painless. He explains that her child's power could bring the universe to its knees, only for Kelly to retort "or lift it to its feet – nothing is born evil." Castiel replies that they can't risk it. When the engine to the truck stalls, Castiel gets a room at a motel. Kelly tells him of her child saving her life, but Castiel assures her it's not a sign of any goodness. He asks who would be there for the baby to raise it if she is gone, just as the fetus begins kicking. Kelly offers Castiel the chance to feel the kicks. Cas puts his hand on Kelly's belly. Her eyes flash and she gets a vision of Castiel jumping in front of her to protect her. Suddenly there is knock at the door. Castiel directs Kelly to the bathroom before opening the door to find Sam and Dean, who demand the Colt back. He tells Sam and Dean his truck broke down and didn't ask for help because he wanted to keep them safe, telling them it's his responsibility and plan. He reveals he is taking Kelly to the sandbox where she and her child will die. Sam attempts to dissuade Castiel by theorizing if they remove the grace, the Nephilim would be rendered human. Castiel remains unconvinced, reminding Sam that he almost died during his grace extraction. Dean eventually convinces Cas and Kelly to return with them to the Bunker and talk things out before making any decisions. As Dean talks with Sam, he gives Castiel the keys to the Impala to let himself and Kelly in. Kelly slides across the front seat to the driver's side, starts the car, and drives off with Castiel to the sandbox. She tells him her child showed her that Castiel will ensure he is born.
Arriving at the sandbox later that evening, Cas and Kelly are greeted by Joshua, who upon exiting the gate is immediately killed by Dagon. Castiel attempts to fight Dagon, but he is easily overpowered and beaten. As she chokes Castiel, Sam and Dean arrive and divert her attention. After she deals with the Winchesters and damages the Colt, she sets her eyes on Castiel once again. Standing up, he joins hands with Kelly. Prepared to die, he waits for Dagon to deliver a killing blow, when he is imbued with the power of the Nephilim. As the energy courses through his body, he is able to block Dagon's attack, and with her arm in his hand he incinerates her, killing her. As Sam and Dean approach him, Cas heals them of their injuries and thanks them. He tells them he has faith that the child must be born. When Sam and Dean try to stop him from leaving, he renders them unconscious with a touch. Inside his truck, Kelly asks what her child told him. As they drive off, Castiel replies that he wasn't told anything, rather he was shown the future.
===12.23 All Along The Watchtower===
:"I have faith."
As Castiel and Kelly are preparing for Jack's birth, Castiel has rented and heavily warded a house in North Cove, Washington, under the name of his vessel, James Novak. When Kelly feels a Braxton-Hicks contraction, a sample of Jack's grace drifts from her and punctures the fabric of the universe, opening a rift leading to Apocalypse World. After she experiences more contractions, the rift begins to expand. As Cas examines the rift, he steps through and is ambushed by a horned tempter demon, but he is saved by that world's Bobby Singer. The two get to talking about their worlds and Castiel discovers that they are in a world where Sam and Dean were never born, and thus never prevented the Apocalypse.
When Castiel returns he is visibly shaken by his experience, but he keeps the existence of the rift from Kelly. She is close to giving birth to Jack and to comfort her, Cas talks about how when Jack's power influenced him, he saw the paradise Jack was going to create. Sam, Dean, and Mary make their way to the house to warn them that Lucifer is free. After Cas heals Dean's injured leg, Sam notices the rift in the backyard. After the three of them enter the rift, Bobby and Cas explain everything that they had talked about, revealing to Sam and Dean they were never born in that universe. After passing back through the rift and meeting up with Crowley, they formulate a plan to trap Lucifer in Apocalypse World to prevent him from reaching Jack. Castiel meets with Kelly one last time before she gives birth to Jack and tells her to remember paradise. He leaves her with Mary who helps her go through the contractions.
When Lucifer arrives at the lake house, Cas charges towards him, but Lucifer easily flings him away. Sam and Dean retreat and lead Lucifer across the rift. While Dean distracts him by unloading a machine gun full of angel blade bullets into him, Sam and Crowley cast a spell to seal the rift, but it requires one more ingredient -- a life. Crowley sacrifices himself to complete the spell. As the rift starts to close Cas crosses over and stabs Lucifer in the chest while Sam and Dean return to their world. As Cas passes back through the rift, Lucifer stabs him in the back with his own angel blade, killing him as Sam and Dean look on in horror. Soon after Jack is born, Mary comes outside armed with Enochian brass knuckles and punches Lucifer repeatedly in the face. As she punches him, he drops Castiel's angel blade and falls back into the rift, but he grabs Mary's arm and takes her with him as the rift closes. As Sam goes to check on Kelly, Dean stays behind and kneels next to Castiel's dead body, whose wings have been burned onto the ground around them.
===13.01 Lost and Found===
Castiel's body is placed in the kitchen of the lake house, while Sam and Dean go on the search for Jack. Sometime later, two angels, Lily and Conrad, locate the lake house and look upon Castiel's dead body. When the angel Conrad tells Lily he always knew Castiel would have a bad end, Lily remarks that he deserved better; Conrad replies that he really didn't.
After Sam and Dean find Jack and deal with the angel threat, they return to the lake house and prepare a funeral pyre for Castiel and Kelly Kline before going back to the Bunker.
===13.03 Patience===
Sam tries to convince Dean to help him keep Jack from going dark side, but Dean is adamant in refusing to save him because Dean blames Jack for Castiel's death. He believes that Jack manipulated Castiel into believing there'd be "paradise on Earth" if he allowed him to be born, and that it got him killed by Lucifer. Jack overhears their entire argument and prays to Castiel.
Castiel, lying in a dark, barren space, wakes up to the sound of Jack calling out for him. As he picks himself up in confusion, he looks out into the vastness of the Empty.
===13.04 The Big Empty===
:"I'm already saved... and you can prance and you can preen... and you can scream and yell and remind me of my failings, but somehow, I'm awake. And I will stay awake and I will keep you awake until we both go insane... I will fight you and fight you and fight you for... ever. For eternity... Release me. Release... me!"
Castiel is wandering the infinite black vastness of the Empty when he inadvertently awakens a Cosmic Entity who is clearly frustrated that Castiel is awake. It takes Castiel's form because its true form would drive any who perceived it insane, and it speaks in an eloquent accent. The Cosmic Entity tells him that the Empty is the place where all demons and angels go to when they die and sleep for all eternity. It claims that it is the only one with any influence and the only reason that it is awake is because Castiel is awake. The Cosmic Entity decides to attack Castiel by infiltrating his mind, reading his memories, and using his biggest failings against him. It beats him to the ground and tells him to sleep forever without having to return to Earth where he will confront his failings, but Castiel believes that he is already saved and uses the fact that he is awake against the Entity, threatening to fight it and keep it awake for all eternity until they both go insane unless it sends Castiel back to Earth.
Later, Castiel is seen waking up in an orchard filled with berries, released from the Empty by the Cosmic Entity and sent back to Earth. He suddenly realizes that he is wearing a new suit much like Jimmy's original outfit, a blue tie, and a longer trench coat.
===13.05 Advanced Thanatology===
Castiel calls Dean from a pay phone, presumably telling him that he is alive and asking him to come pick him up. At an unknown location, Sam and Dean pull up towards him in the Impala and step out, stunned to see a revived Castiel.
===13.06 Tombstone===
:"Jack, I've killed people who didn't deserve it... my friends -- I've killed people I loved. I wish I could tell you that it -- that it gets easier, that with time, it hurts less, but that would be a lie because it -- it never gets easier. And those moments, they never stop hurting. But that doesn't mean that you should stop fighting. It doesn't mean that just because you made a mistake -- and that's what this is, Jack. It's a mistake. That doesn't mean that you can't -- can't be better, do better. I believe that. I have to believe that."
===13.07 War Of The Worlds===
:"You'll forgive me if I'm a little on edge. The last time we were together, you killed me."
In an attempt to find the missing Jack, Castiel decides to meet with one of his angel contacts for information, but refuses to let Sam and Dean come along. At the portal to Heaven, Castiel meets with Dumah, who reveals that the angels don't have Jack. She says that if they did, they would enslave him to make more angels, to Castiel's shock and horror. Dumah reveals that the angels, after all of their losses, are very nearly extinct. Castiel wasn't aware of this, but still refuses to help his siblings capture Jack. Castiel fights with Dumah and two other angels before they are interrupted by the unexpected return of Lucifer, who scares off the other angels. Castiel realizes that the archangel is in a weakened state, but Lucifer insists that he is still too strong for Castiel to kill and despite Castiel's reluctance, insists on meeting with him to discuss the situation.
Traveling to a bar, Lucifer reveals to Castiel the threat from the Apocalypse World Michael and is frustrated that the Winchesters have lost his son. Though Lucifer wants to work together, Castiel is reluctant to trust the archangel as Lucifer had killed him the last time they met. Lucifer points out that Castiel stabbed him that time too, causing Castiel to give a sarcastic apology. Though Castiel tries to call the Winchesters and warn them, Lucifer stops him as he feels the Winchesters will only complicate things. Lucifer and Castiel's meeting is interrupted by the arrival of the demons led by the Prince of Hell Asmodeus. Aware of Lucifer's weakened state, Asmodeus refuses to bow to him and subdues and captures both Lucifer and Castiel. By the time Sam and Dean arrive, Asmodeus and the angels are gone with only Asmodeus' henchmen left to ambush the hunters.
Dean later calls Castiel to check on him. Posing as Castiel using his shapeshifting powers, Asmodeus claims that "he" tried to call and warn them but couldn't get a signal. Asmodeus, as Castiel, lies that he is following a very interesting lead and will let the Winchesters know when he knows more. At the same time, Castiel and Lucifer are locked in cells next to each other in Crowley's Lair. Asmodeus explains to Arthur Ketch that he's a collector and Lucifer could be useful while Castiel is a card he can play if the Winchesters get out of line. Needing Jack if Michael is indeed coming, Asmodeus hires Ketch to find him.
===13.12 Various & Sundry Villains===
:"Jack would rather kill you than hug you. Seems relevant. Did you know he doesn’t – he doesn’t even really look like you? And he reminds me so much of his mother."
Castiel and Lucifer remain locked up together in Crowley's Lair where they are taunted by the demon Dipper and Castiel continually refuses Lucifer's requests for Castiel to share some of his grace with the archangel. Castiel eventually tells Lucifer a bit about Jack and Lucifer eventually discovers that using his anger, he can tap into some of his depleted powers. The two angels team up together to escape, drawing Dipper in with an argument which allows Lucifer to surprise and overpower the demon before burning through the warding on their cells. Released from his prison, Castiel smites Dipper and works with Lucifer to kill a group of demons and escape the lair.
Outside, the two are forced to stop due to Lucifer exhausting himself in his weakened state. Lucifer continues to try to convince Castiel to give him some of his grace, but Castiel refuses to trust the archangel after how their previous alliance against the Darkness turned out. Lucifer attacks Castiel, attempting to take his grace by force and wounding Castiel. In the archangel's weakened state, Castiel is able to hold his own against him and wound Lucifer with an angel blade, though he is unable to kill Lucifer even in his weakened state.
===13.13 Devil's Bargain===
:"Lucifer!!! Where are you?!"
Awakening in the woods following his fight with Lucifer, Castiel returns to Crowley's Lair to find the archangel gone.
Returning to the bunker, Castiel informs the Winchesters of his capture by Asmodeus, the return of Lucifer, the threat of Michael and how an alternate Kevin Tran was able to open the rift using the angel tablet. Inspired by Kevin's actions, the Winchesters decide to have Donatello Redfield translate the demon tablet in hopes that it will also hold a spell to open a rift so they can return to Apocalypse World and rescue Mary and Jack, though Castiel is somewhat dubious of the plan to capture Lucifer and use his grace for the spell.
After receiving a message on angel radio about a dead Cupid, Castiel investigates with the Winchesters and they quickly realize that the culprit was Lucifer who is stealing angel grace to power himself back up. From a homeless man, Sam is able to learn of Lucifer going to see Sister Jo, but when the three investigate, they only find Ketch, also looking for Lucifer. When Ketch proves to be uncooperative, Castiel knocks him out and whole-heartedly approves of the plan to kill Ketch and flush his ashes to prevent him from returning again. After Sam finds footage of Sister Jo, Castiel recognizes her as Anael, another angel and they are able to track down the two through Sister Jo's credit cards. When confronted by the three, Anael claims that Lucifer is weak and an easy target, but is lying as she is in league with Lucifer who has powered himself back up a great deal by feeding periodically partially on Anael's grace before allowing it to recharge and then feeding again. Lucifer easily overpowers the three, but Ketch drives off Lucifer and Anael with a demon bomb.
In the aftermath, Ketch explains that he managed to escape and used the demon bomb as he thought it might "put a dent" in Lucifer in his weakened state, but Castiel recognizes that Lucifer's weakened state was greatly exaggerated and is left confused by Anael's role in events as she was only a low-level functionary in Heaven. Ketch proposes an alliance against Lucifer, revealing that he is working for Asmodeus as a gesture of his sincerity. Castiel is dubious of Ketch's offer to pass along information and act as a double-agent, but Ketch reminds them that he is the lesser of at least three evils and claims that Lucifer being on the loose again crosses a line that even he has to draw despite them seeing Ketch as a monster. Ketch requests that they at least wait to murder him until he can prove useful which the Winchesters and Castiel reluctantly agree to.
Back at the bunker, Castiel questions if they can trust Ketch which the Winchesters acknowledge that they can't, but they do need him for now. Dean makes it clear that they will Ketch when they are done while Donatello has discovered that the spell they need is in fact on the demon tablet and they now have a plan. However, Castiel becomes suspicious of Donatello's strange behavior.
===13.14 Good Intentions===
:"If I hadn't acted we would still be sitting around talking about what to do next, we would be wasting time. And it's time we don't have Dean. I told you, war is coming. War. And I did what soldiers do. Now we needed the spell to open the rift, and I got it. We need four major ingredients: The grace of an archangel. A fruit from a tree of life. The Seal of Solomon and the blood of a most holy man. We find those things, we can bring everybody home. And together we can beat Lucifer and Michael. This is the only way we win. This is the only way we survive. It's like you said Dean. Whatever it takes."
As Donatello Redfield continues his translations of the demon tablet, Castiel supplies him with food while being continuously worried about Donatello's mental state. Castiel reminds the Winchesters that as they still need archangel grace, they should be looking for Lucifer, but they assure him that they are on it. Castiel expresses worry about Michael succeeding in getting to their world first, but Dean brushes off his concerns and instead insists on focusing on getting Donatello whatever he needs to translate the spell for them. Donatello eventually cracks the spell and brings them the list of ingredients which, to their surprise, do not include archangel grace, causing Sam to speculate that as its a different tablet, the spell is different. However, the spell requires the hearts of Gog and Magog, surprising Castiel as he hadn't thought them to be real. Donatello explains that according to the demon tablet, they were real and enslaved half of the Fertile Crescent until priests sealed them away. Due to the danger posed by Gog and Magog, Castiel decides to handle getting their hearts with Dean while Sam and Donatello prepare the spell.
As he leaves with Dean, Castiel reminds Dean of how he was dead and resurrected and Jack's part in all of it. Castiel believes that he was brought back for a reason and suggests that it was to prepare to fight Michael who will bring war upon them. After reaching an empty field, Dean and Castiel arm themselves with angel blades per Donatello's instructions that Gog and Magog can only be killed by a weapon touched by God and Castiel summons the two warriors with a spell. Castiel translates their speech for Dean before they are attacked. Castiel fights Gog who proves to be more than a match for the angel while Dean's angel blade is broken by Magog's sword, causing Castiel to translate that the weapons were forged by a god. After a brief fight, Gog prepares to stab Castiel with his sword, but is killed by Dean using Magog's sword, having realized that the swords, being forged by a god, fit the description Donatello gave them. Castiel discovers that Gog and Magog were in fact primitive beasts made of rock sand, an ancient species that Castiel had believed went extinct in the Great Flood. As a result, they do not have hearts and Castiel and Dean realize that Donatello has betrayed them.
Returning to the bunker, the two discover that Donatello attacked Sam and has begun crazily muttering in the dungeon. Dean and Castiel explain how they were set up by Donatello who wants them all dead. Castiel watches through a camera as the Winchesters interrogate Donatello who explains that he translated the tablet and saw all the power of God and now believes that they want to take it from him and then uses a spell to try to suffocate Dean. Afterwards, the three try to figure out what happened to drive Donatello insane and while Castiel has heard of a Prophet who was tempted, he had never given in. Sam realizes that the difference between Donatello and Kevin Tran is that Donatello is soulless, alarming Castiel who explains that the human soul acts as a filter, inoculating the Prophet against whatever darkness exists within the tablet.
The Winchesters are left in despair because they had been so close and they have no way to restore Donatello's soul. Castiel points out that even if they could, Donatello is already corrupted and suggests that the kindest thing to do would be to kill Donatello and get the next Prophet in line to translate the spell for them. However, the Winchesters refuse to kill Donatello as they just need the spell. Fed up with the arguing, Castiel decides to take action, locking Sam and Dean out of the dungeon. Castiel confronts the restrained Donatello who confirms that he gave them the wrong ingredients and though he knows the right ones, refuses to give it to them. Castiel reveals that he is going to do something that he promised to never do to a human without their permission: he is going to strip the spell from Donatello's mind. Donatello warns Castiel that he has absorbed too much power and trying could fry them both, but Castiel is undeterred and stops Donatello from casting a spell before painfully stripping the spell from his mind. Afterwards, Castiel emerges from the dungeon stating that he knows what they need to do, leaving Donatello unconscious.
Later, Sam and Dean return to the bunker and angrily reveal that while Donatello is still alive, he is brain dead, only kept alive on life support. Unrepentant, Castiel states that Donatello's soul was gone and he was corrupted and a danger to humanity before revealing that Donatello was working with Asmodeus, albeit unwillingly. Castiel states that some people just can't be saved and while no one gave him the power to make that decision, he took it. Without Castiel having acted, they would still be talking and arguing about to what to do, wasting time that they don't have as war with Michael is coming. Instead, they now have the spell they need to open the rift. Castiel reveals that they need the grace of an archangel, fruit from the Tree of Life, the Seal of Solomon and the blood of a most holy man. With those four ingredients, they can bring everybody home and together beat Lucifer and Michael. Castiel is insistent that this is the only way they will win and survive and they must do whatever it takes.
===13.15 A Most Holy Man===
Castiel is mentioned to be in Syria searching for fruit from the Tree of Life.
===13.16 Scoobynatural===
:"Sam? Dean? I'm back from Syria with fruit from the Tree of Life. The tree was guarded by a pack of djinn. I killed most of them, bargained with the rest. Think I'm... technically married to their queen now."
Castiel returns from Syria with fruit from the Tree of Life, starting to tell a story about how he had to fight a pack of djinn for it before technically getting married to their queen. Shortly thereafter, Castiel is sucked into Scooby-Doo, Where Are You! by the Phantom Ghost Kid, arriving in time to witness the Impala and Mystery Machine beginning to race. Castiel follows the Winchesters to Colonel Sanders's mansion where he is initially mistaken for the ghost.
During the case, Castiel is teamed up with Scooby-Doo and Shaggy Rogers, much to his initial annoyance, though he quickly grows fond of the two. While searching the basement, the trio are ambushed by the ghost surprising Castiel, as he has never seen a ghost wear such a ridiculous costume before. After Castiel's hand passes through the ghost, he is dragged off by Scooby and Shaggy, and joins the others in a chase throughout the mansion. After Shaggy is flung off the balcony by the ghost, Castiel jumps after him and Scooby, using his trenchcoat as a makeshift parachute to slow their fall, though Shaggy still breaks his arm.
Later, as the group prepares to trap the ghost, Castiel joins Scooby and Shaggy in acting as bait, swiftly carrying the other two away when the ghost shows up. However, Castiel, Scooby, and Shaggy fall into Fred's trap instead and become stuck in a washing machine. Using the Plan B, the group is able to trap the ghost in a salt circle, revealing him to be a young boy, to Castiel's shock. When the boy explains how Jay was using him, Castiel expresses sympathy for his predicament and joins the Winchesters in tricking the Scooby Gang into thinking the whole experience wasn't real. Before parting ways, Castiel heals Shaggy's broken arm and thanks Scooby and Shaggy for the lesson they taught him about courage in the face of danger.
After returning to their world, Castiel is saddened along with Sam and Dean when they set the ghost free, and he joins the two in exposing Jay's actions, taking pleasure in informing Jay that the ghost kid's soul is now free. After Jay's arrest, Castiel is annoyed by Dean's antics, telling Dean that he isn't a talking dog.
===13.18 Bring 'em Back Alive===
:"No. You cannot turn your back on your father's creation."
After the revelation of Gabriel's survival and his rescue by Arthur Ketch, Castiel returns to the bunker to help tend to the near-catatonic archangel and is frustrated to learn that Dean has gone to Apocalypse World with Ketch. Sam and Castiel try to feed Gabriel his grace that Ketch recovered from Asmodeus without success, but Gabriel writes his story in Enochian on the walls of his room, giving them hope that Gabriel's mind is still in there. By translating the story, Castiel and Sam are able to learn that Gabriel faked his death when Lucifer stabbed him and was eventually captured and sold to Asmodeus. Unable to heal an archangel, Castiel tries to jolt Gabriel's mind to awareness with his powers, but its Sam's pleas that seem to finally reach Gabriel who reabsorbs his grace before they get a threatening call from Asmodeus demanding that they turn Gabriel over to him.
Asmodeus leads a demonic incursion into the bunker to recapture Gabriel. During the fight, Castiel overpowers one demon and smites another that gets the better of Sam, but they are both taken down and tortured by Asmodeus. Castiel and Sam's predicament finally snaps Gabriel out of it and he fights back against his captors, healing the injuries he suffered from Asmodeus' torture. Gabriel proves to be more than a match for Asmodeus and kills the Prince of Hell. However, he refuses to join the fight against Michael and Lucifer and departs the bunker after Castiel and Sam fill him in.
When Dean returns from Apocalypse World, Castiel and Sam reveal the death of Asmodeus and the departure of Gabriel. Having been unable to find Mary in the twenty-four hours he had in the other world and lacking Gabriel or his grace to reopen the doorway, Dean is left extremely frustrated by this news.
===13.19 Funeralia===
:"You stole my memories and you threatened to tear me apart and you made me repeatedly act out Dean Winchester’s murder and you killed many many people."
Castiel attempts to seek out the help of Heaven to find Gabriel and is shocked by how depressed Inias is while guarding the portal. In Heaven, Castiel asks Dumah and the other angels for help, but after making Castiel wait for a long time, they tell him they can't. As Castiel continues to demand their help, to his shock Naomi appears to confirm Dumah's claims. Naomi explains to Castiel that she survived Metatron's attack, but took years to heal to the point that she's now "mostly here" and so faked her death. Castiel is angered to see Naomi after all she did the last time they met, but Naomi reveals to him that there are less than a dozen angels left alive and they will soon burn out if something doesn't change. When the angels die, Heaven will fall without them there to power it. As a result, no angel can leave Heaven now without risking this. Castiel is stunned as he knew their numbers were low, but not that bad. Naomi reveals that Gabriel's power as an archangel could save Heaven if he could be found and convinced to return to Heaven.
Castiel later returns to Earth with Naomi who informs him that Heaven will now be sealed off until the situation is resolved one way or the other. Castiel and Naomi acknowledge the gravity of the situation they are facing and Naomi promises that the angels will keep Heaven going for as long as they can.
===13.21 Beat the Devil===
:"I was used by Lucifer, too. It was the worst possible violation. So, I-I'm not taking your reluctance lightly, but he's already out there, and we've been ignoring it and avoiding dealing with him because we're afraid. We let Lucifer out of the Cage, and he has never stopped being our responsibility."
===13.22 Exodus===
:"I vastly prefer them to angels."
Following the reunion of the Winchesters and the return of Lucifer, Castiel does his best to keep Lucifer and Jack separate, becoming worried when Jack shows an interest in his father. After Ketch and Charlie Bradbury are captured by the angels, Castiel uses his powers to torture their location out of a resistance traitor and joins the rescue mission. During the mission, Castiel comes face to face with his Apocalypse World counterpart, who is shocked that Castiel chose the side of the humans. Castiel informs his counterpart that he vastly prefers humans over angels. When the Apocalypse World Castiel states that the two of them are the same, Castiel agrees with the sentiment, and kills him.
During the exodus through the rift, Castiel leads the way with Ketch and is surprised to find Rowena on the other end still holding it open. Afterwards, Dean informs Castiel of Gabriel's death and reassures him that Sam took care of Lucifer, having stranded the archangel in Apocalypse World.
===13.23 Let The Good Times Roll===
:"I can hear three. Wait, maybe -- maybe four. They're talking about whether Kylie Jenner would make a good mother. The consensus is no."
In the aftermath of the rescue of the people from Apocalypse World, Castiel joins the Winchesters and Jack on a werewolf hunt, using his angel powers to listen in on their conversation and killing one with his angel blade.
After Maggie is brutally murdered, Castiel joins the investigation which points to a boy named Nate that she has a crush on. Castiel, Sam and Dean rush to stop Jack from hurting Nate, forcing Dean to shoot Jack to get his attention. To their shock, Michael appears and attacks, forcing Dean to use Holy Fire to keep him at bay so that they can escape.
At the bunker, the three discover that Maggie has been resurrected by a returned Lucifer who they soon realize was her original killer. Michael attacks the bunker and Castiel joins Sam and Dean in trying to defend it to no avail while Mary and Bobby flee. Jack returns with Lucifer, badly injuring Michael and stopping the battle. However, after Jack turns on Lucifer when the truth about Maggie's murder is revealed, the archangel steals his son's grace and disappears with Jack and Sam. To Dean and Castiel's shock, Michael reveals that with his son's grace, Lucifer is now super-charged and can end the whole universe if he wants. Michael is now too weak to stop Lucifer, particularly in his current battered vessel. Remembering Zachariah and Gabriel telling him of his destiny as the Michael Sword, Michael's one true vessel, Dean offers a deal to Michael where he will become Michael's vessel to fight Lucifer against Castiel's objections as Dean feels that they have no choice. Michael accepts a deal where Dean will become his vessel, but Dean will be in control to fight Lucifer, allowing Dean to finally kill Lucifer with the archangel blade. However, Michael betrays their deal after Lucifer's death, takes full control of Dean's body and vanishes.
When Mary and Bobby return to the bunker, a despondent Castiel is sitting alone on the floor. Castiel simply gives his friends a sad shake of his head, aware of what has befallen Dean.
===14.01 Stranger In A Strange Land===
:"You've got me. You have all of us. You have your family. And -- And we are going to find Dean, and we are going to beat Michael and we are going to do it together. We -- Because that's what we do."'
Six weeks after Dean's disappearance, Castiel joins the effort to find him by meeting with the demon Kipling for any leads that Hell might have. However, Kipling betrays Castiel by having the bar filled with demons who are able to overpower and capture the angel, though he is left relatively unharmed. Kipling subsequently uses his capture of Castiel to arrange a meeting with Sam.
When Sam arrives, Castiel remains bound, but assures Sam that he is alright. Kipling reveals that he wants to become the new King of Hell following the death of all of its previous leaders and wants to make "the Crowley deal" with Sam. However, Sam refuses, recognizing that Kipling is no Crowley and is pure evil. A battle breaks out between the hunters and the demons, ending when Sam kills Kipling with the demon-killing knife and declares that there will be no more Kings of Hell ever again.
In the aftermath, Sam reveals to Castiel the failure of Ketch to get the hyperbolic pulse generator, the device they used to exorcise Lucifer from President Jefferson Rooney. Castiel comforts a downtrodden Jack who got easily beaten in the battle without his powers to help him.
===14.02 Gods And Monsters===
:"You know... in all my thousands of years... what happened to Jimmy Novak... and his family... it's my greatest regret."
===14.03 The Scar===
:"What you did today, you just made me so proud. You know, learning to hold your own in a fight without your powers, that takes time and -- and training, but today, you -- you proved that you have the mind of a hunter and the heart of a hunter."
Castiel is stunned by the return of Dean and helps him remember a confrontation between Michael and Dark Kaia. Jules returns with Lora, a young woman cursed by a witch and inexplicably aging. Unable to heal Lora, Castiel remains behind with Jules to try to save her life as the Winchesters hunt for Dark Kaia. They are joined by Jack, who was originally planning on leaving the bunker but stays to help after seeing Lora's state. Using a spell from the White Magic Lexicon suggested by Rowena, Castiel and Jules try and fail to break the spell on Lora, who dies shortly thereafter. However, Jack realizes that it wasn't Lora that was cursed, but the witch's pendant. By smashing the pendant, Jack is able to restore Lora's lifeforce and resurrect her.
Afterwards, Castiel visits Jack in his room and expresses how proud he is of the young man. Castiel tells Jack that while learning to fight without his powers will take time and training, Jack has proven that he has the mind and heart of a hunter, and he promises to help convince Dean to allow Jack to hunt again. In turn, Jack hides from Castiel that he is now coughing up blood.
===14.07 Unhuman Nature===
:"This feels different. Losing, um... a son... feels different."
===14.08 Byzantium===
:"Because I made a promise. Because I love you, Jack. And Sam and Dean-- they love you. And they are fighting for you at this very minute. I hope that… They don't need to know what happened here. What I did-- I'm-- I'm-- I'm at peace with my choice. I don't want them to worry."
Jack dies of his affliction, devastating the Winchesters and Castiel. The three spend the night drinking and sharing stories and in the morning, Sam calls in Lily Sunder in hopes that she can read Kevin Tran's angel tablet notes and find something that can help them to save Jack. Displaying none of her previous antagonism towards Castiel, Lily determines that she can't read the notes, but offers a solution using her Enochian magic to sacrifice a piece of Jack's own soul to sustain him. Castiel realizes that if Jack is in Heaven, he can pull Jack's soul back into his body for just long enough for Jack to perform the spell. However, Lily demands that the Winchesters ensure that what remains of her own soul get into Heaven in exchange. Castiel tells the Winchesters about Anubis, the deity used to determine where a person's soul will end up, but receives a distress call over angel radio that reveals that something has happened in Heaven and all of the gates have been thrown open, even the ones that Metatron closed. Castiel leaves the Winchesters to deal with Anubis and Lily while he travels into Heaven to find Jack and uncover what is happening.
In Heaven, Castiel finds the place virtually abandoned and learns from Dumah that Heaven has been invaded. Searching Jack's Heaven, the two find him missing, but are met with Naomi who explains that the Cosmic Entity from the Empty, the same being that resurrected Castiel, has invaded Heaven in search of Jack's soul due to his half-angel nature before Naomi is consumed by the Entity as well like all of the rest of the angels.
Continuing his search, Castiel finally locates Jack's soul in Kelly Kline's Heaven where he is warmly reunited with his old friend. Though Jack is dead, Kelly states that Castiel still kept his promise to her since Jack is so wonderful. Castiel proposes to Jack their plan to bring him back, which worries Kelly because it will sacrifice part of his soul. However, it will also cause the Entity to leave Heaven since Jack will no longer be there. The Entity reveals itself to be possessing Dumah and attacks to take Jack to the Empty as Dean prays to Castiel that they are ready on Earth. Unable to defeat the Entity, Castiel offers to trade himself in Jack's place if the Entity will allow him to return to life. Castiel reminds the being that it could be eons otherwise before it gets him and the Entity accepts, but states that it will only take Castiel once he is truly happy. After the Entity leaves, Castiel asks Jack not to tell the Winchesters as Castiel doesn't want to burden them with his choice which he is at peace with. Jack accepts and after a goodbye with his mother, Castiel resurrects Jack, allowing him to complete the spell and be cured.
After departing Kelly's Heaven, Castiel is greeted by Naomi who thanks him for his actions even if they weren't done to save Heaven. In turn, Naomi offers Castiel the location of Michael as a reward. Upon returning to Earth, Castiel shares this news with the Winchesters and Jack who celebrate both Jack's return and knowing where to attack Michael.
===14.09 The Spear===
===14.10 Nihilism===
===14.12 Prophet And Loss===
:"Dean, if there is a spark – a hope – then I have to try. You taught me that."
Investigating a series of strange murders, the Winchesters contact Castiel, still at the bunker, to ask him about Tony Alvarez. Castiel identifies Tony as the next Prophet in line after Donatello Redfield and does his best to dissuade Dean from his plan to use the Ma'lak Box to trap himself and Michael. Following Tony's suicide, Castiel theorizes that Donatello's state between life and death created a Prophet that was not only premature but malformed. The three realize that the only way to set the Natural Order right again is to end Donatello's life so that the next Prophet is properly formed.
When the Winchesters arrive at the nursing home where Donatello has been in a persistent vegetative state, they are surprised to find Castiel there, disguised as Dr. Novak. Dr. Rashad tells them that there has been no improvement from Donatello beyond occasional spasms and mumbled word and takes Sam to show him while Dean confronts Castiel over his presence. Castiel explains to Dean privately that what happened to Donatello, while necessary, was his fault and he regrets it, wishing there could've been another way. Castiel takes the opportunity to confront Dean over his suicidal plan, but Dean brushes off his attempts to talk.
Their argument is interrupted by the return of Sam who shows them a video of Donatello speaking in Enochian from a few days before. Castiel realizes that Donatello's mind is trying to rebuild itself and organize his memories and the Word of God. As a result, Donatello is no longer beyond help and Castiel can fix him. Castiel pointedly tells Dean that as long as there is some kind of hope then he has to try and that Dean taught him that. After kicking out Dr. Rashad, Castiel spends some time going through Donatello's mind, trying to help wake him up. When Sam and Dean return, Castiel has not yet finished and states that he has found "something uncertain." Moments later, Castiel finds what he's looking for and Donatello regains consciousness. Donatello remains alive after Dean shuts off life support, proving that Castiel has succeeded.
In the aftermath, Castiel and Dean help Donatello get some food. Castiel reassures Dean that Donatello is no longer his twisted corrupted self and is back to normal, though Donatello remains soulless. Dean is pleased with the result and leaves Castiel to fill Donatello in on recent events.
===14.13 Lebanon===
:"My name is Castiel. I'm an angel of the Lord."
In an alternate timeline where John Winchester disappeared in 2003, Castiel arrives in Lebanon, Kansas, with Zachariah to investigate who is messing with time. Due to never having met Sam and Dean, Castiel remains a loyal and unquestioning soldier of Heaven. When Castiel displays his wings threateningly, he draws the attention of the Winchesters, whom Zachariah orders Castiel to kill. With no memory of his best friend, Castiel mercilessly attacks Dean and tries to kill him, beating on Sam when he tries to intervene. Unable to defeat or reason with the alternate version of their friend, Sam creates an angel banishing sigil from the blood created by his injuries and banishes Castiel before he can kill Dean.
During the episode, the original Castiel is stated to be on a hunt with Jack, Jules, and the other hunters. After the Winchesters return their father to his own time, Castiel is restored to normal and later arrives at the Bunker, wondering what has happened.
===14.14 Ouroboros===
:"But, Jack... You know, Sam and Dean, they're human, and they're very extraordinary, brave, special humans, but they're -- they're still humans. And humans burn bright, but for a very brief time compared to, you know, things like us. And eventually, they're gone, even the very best ones, and we have to carry on. It's just -- It's part of growing up."
===14.15 Peace Of Mind===
:"Sam, I know you want to be happy. And I know what it's like to lose your army. I know what it's like... to fail as a leader, Sam. But you can't lose yourself. You have to keep fighting. You can't lose yourself, because if you do, you fail us. You fail all of those that we've lost. You fail Jack. Sam, you fail Dean."
===14.17 Game Night===
:"You know, He does meddle. God reached down, and He brought me back to life."
===14.18 Absence===
:"I was scared. I had believed in Jack for so long. I believed that he was good. I knew he would be good for the world. And he was good for us. My faith in him, it never wavered, and then I saw what he did. It wasn't malice. It wasn't evil. It was like Jack saw a problem, and in his mind, he just solved it with that snake... What he did wasn't bad. It was the absence of good. And I saw that in him. But we were a family, and I didn't want to lose that, so I thought I could... fix it on my own. Felt like it was my responsibility. So I left and didn't tell you. If I could go back and just talk to him right then and there, I would. But I can't, Dean. I failed you. And I failed Jack."
===14.19 Jack In The Box===
:"A hunter's memorial, complete with monster. Mary would've appreciated that."
Castiel attends Mary Winchester's hunter's memorial which is interrupted by Bobby killing a Wraith that is in attendance. Castiel notes that Mary would've appreciated having a hunter's memorial complete with a monster, a sentiment that Bobby agrees with.
After the memorial, Castiel begins searching for Jack, traveling to Heaven to seek Naomi's assistance. However, Dumah reveals that she has overthrown Naomi following the invasion by the Cosmic Entity and is intrigued by Castiel's description of Jack's soulless state. After learning of Dumah's efforts to establish a reign of terror using a manipulated Jack, Castiel attempts to return to Heaven to retrieve Jack but is blocked by Eremiel. Castiel is able to overpower the other angel and force him to let Castiel into Heaven where he confronts Dumah over her actions. Dumah is unrepentant, but refuses to let Castiel leave with Jack. When Castiel challenges her on the issue, Dumah threatens to end John and Mary's peaceful shared Heaven with a snap of her fingers if Castiel fails to comply. Enraged by the threat against his friends, Castiel instantly draws his angel blade and kills Dumah before heading off in search of Jack.
Upon returning to Earth, Castiel is enraged to learn that Jack has been tricked into the Ma'lak Box. To Sam, Dean and Castiel's shock, Jack is able to break free of the box powerful enough to hold an archangel, destroying it in the process.
===14.20 Moriah===
:"He's a writer. Writers lie."
===15.01 Back And To The Future===
:"Dean, I can't. I-I... I can't even look at him."
As the zombies swarm them, Castiel fights them off with his angel blade and smiting. However, as the Winchesters and Castiel start to get overwhelmed, Castiel grabs Jack's corpse and leads them into a nearby crypt for safety where they discuss options. As the zombies are just corpses possessed by the Hell Ghosts, Castiel suggests salting and burning their bodies to get rid of them, but that idea is shot down. The three are joined by the demon Belphegor who possesses Jack's corpse, much to Castiel's disgust and ignores Castiel's orders to get out of Jack. Belphegor insists that he can help them as he wants Hell returned to normal and Castiel reluctantly gives the demon some of his blood for a spell to eject the souls from the corpses they are possessing.
After escaping the cemetery, the group finds the aftermath of an attack by the escaped ghost of Constance Welch and Belphegor suggests a spell to create a mile-wide barrier to contain the escaped ghosts until they can find a solution to deal with them. Castiel realizes that the town of Harlan, Kansas is within that radius and the Winchesters decide to evacuate Harlan for protection of the residents. Dean assigns Castiel to help Belphegor prepare for the spell, but Castiel refuses as he can't even look at the demon possessing the body of his surrogate son and so decides to help Sam clear out the residents while Dean helps Belphegor instead.
Armed with a shotgun loaded with rock salt, Castiel joins Sam in clearing out the houses. Castiel arrives in time to save Sam from the ghost of serial killer John Wayne Gacy and heals Sam's wound from the ghost. However, Castiel proves to be unable to heal Sam's wound from the Equalizer, getting a disturbing vision when he tries and sensing a strange energy that he has never felt before from the wound. Sam and Castiel rescue a mother and daughter from Gacy's ghost, but have to fight off Gacy, Mary Worthington and two other Hell Ghosts to escape. Though he is briefly overpowered, Castiel manages to recover his shotgun and save Sam. With Belphegor succeeding in establishing the barrier, the group manages to escape to the other side, leaving the Hell Ghosts trapped within.
With the ghosts trapped, Castiel, Belphegor and the Winchesters bring the mother and daughter to the high school where the residents have been evacuated and convince them not to say anything about what they saw. Things remain awkward between Castiel and Dean and the angel brushes off Belphegor's offer to talk about it.
===15.02 Raising Hell===
:"Even if we didn't know that all of the challenges that we face were born of Chuck's machinations, how would we describe it all? We'd call it "life." Because that's precisely what life is. It's an obstacle course, and maybe Chuck designed the obstacles, but we ran our own race. We made our own moves. And mostly, we did well with that."
===15.03 The Rupture===
:"Jack's dead. Chuck's gone. You and Sam have each other. I think it's time for me to move on."
With more Hell Ghosts escaping, Rowena attempts to use a spell from the Book of the Damned to strengthen the barrier. However, the spell fails as the ghosts are too strong and the barrier too weak. After the failure, Belphegor visits the rupture to Hell, joined by Castiel who continues to remain suspicious of the demon's motives. Belphegor reveals that the rupture is not a gate or portal, but a tear God opened straight into Hell itself and suggests using Lilith's Crook to draw all of the souls and demons back in. Though the Crook is locked in Lilith's Chamber, the Chamber was opened by God along with all of the other doors in Hell. However, Belphegor demands that Castiel accompany him into Hell as protection from the remaining demons while the Winchesters and Rowena use the Sanetur Acre Vulnus spell to close the rupture. Dean, without hesitation, agrees to Castiel joining the demon, much to Castiel's frustration.
After shoving Belphegor into the rupture, Castiel jumps in after the demon and travels through Hell with him. Castiel's suspicions of Belphegor continue to grow as he learns that Hell has been emptied out of demons which Belphegor already knew and thus didn't need Castiel's protection. Belphegor claims that he just wanted company and notes the strained relationship between Dean and Castiel. In Lilith's Chamber, the two find the demon Malfayan raiding Lilith's treasures and Castiel kills the demon after its confirmed that he doesn't have the Crook. Belphegor leads Castiel to a box sealed with an Enochian prayer to Lucifer which contains the Crook and Castiel realizes that Belphegor actually needed his help to open the box. Much to Castiel's discomfort, he is forced to sing the prayer to open the box, only to have Ardat attack them. Ardat reveals to Castiel that Belphegor is actually seeking to become King of Hell before Belphegor kills her with an angel blade.
Castiel confronts Belphegor who tries to convince Castiel to leave before throwing him out of Lilith's Chamber with telekinesis. Belphegor reveals that Ardat was telling the truth and Belphegor intends to use the Crook as a siphon to absorb all the souls and demons of Hell into himself to gain unlimited power. Belphegor sounds the Crook, drawing all of the souls and demons inside of it, but Castiel fights his way through the strong wind the Crook produces and beats the demon to the ground. Belphegor attempts to trick Castiel by pretending to be Jack, but Castiel easily sees through it and smites Belphegor, killing him. However, Castiel's smiting burns Jack's corpse into a charred skeleton and destroys the Crook, preventing all of the souls and demons from returning. Castiel is able to climb out of the closing rupture and reveals the death of Belphegor and failure of their plan to an angry Dean. Before the argument can continue, Rowena uses the Death Is an Infinite Vessel spell to draw all of the remaining souls and demons into herself. With a final goodbye to the Winchesters and Castiel, Rowena sacrifices herself to cast Hell's denizens back where they belong before the rupture seals.
In the aftermath, with Rowena's death compounded by the news of Ketch's murder, Dean erupts into an argument with Castiel over his actions, blaming everything going wrong on the angel. Castiel insists that Belphegor was too great of a threat and had to be stopped, but Dean states that they could've dealt with him afterwards. Castiel realizes that Dean still blames him for the death of Mary Winchester and that he is as good as dead in Dean's eyes. Castiel reveals to Dean that his powers are failing which he has been trying to tell Dean for some time, though Dean has always refused to listen. With Jack dead and Chuck gone, Castiel decides that its time for him to move on and leaves the bunker.
===15.05 Proverbs 17:3===
Castiel is shown to be ignoring text messages from Sam. Sam later calls Castiel and leaves him a message about the renewed threat from God and the resurrection of Lilith.
===15.06 Golden Time===
:"It's always you -- you selfish little men in positions of authority. You take what you want, you take who you want. And you believe that your power will protect you. Well, it won't protect you from me."
Since his departure from the bunker, Castiel takes a vacation fishing in Wyoming, though without much success in fishing. However, he learns of the strange death of a local boy and realizes that it may be a case. Castiel finds Sheriff Alden Roy to be uncooperative, forcing Castiel to call the bunker to get confirmation of his FBI cover. Though Dean backs him up, he admonishes Castiel for ignoring their calls and voicemails and hangs up on him. Going through the case files, Castiel finds many strange deaths in the area and marking them on a map, finds a good location to search for the culprit.
As Castiel begins his search for the monster, which he suspects to be a djinn, he is joined by Melly Krakowski whose son Caleb has gone missing. Melly leads Castiel towards an abandoned mine that he suspects may be the djinn's lair while he tries to warn her about what they might find while shielding her from the truth at the same time. The two locate Caleb who had escaped the monster who proves to be Sheriff Roy. The djinn tries to shoot Castiel dead, but his angel powers leave him unharmed and his wounds heal right in front of the stunned humans and monster. Knocking Sheriff Roy to the ground, Castiel brutally kills the djinn with several stabs from his angel blade.
After killing the djinn, Castiel dumps his body in the lake and heals Caleb's injured leg. However, Castiel's failing powers cause him to struggle with healing the minor injury. Though Melly questions his powers, Castiel decides that its better for her and Caleb not to ever understand what happened and thanks her for their time together. Castiel has realized that if he stays, nothing will ever change so he must return to helping people and end his vacation.
===15.07 Last Call===
:"Dean, I need you to call me back. Sam is hurt, and I... Where are you?!"
===15.08 Our Father, Who Aren't in Heaven===
:"You know, Michael, I never really liked you. Even when I was just another angel I thought you were too haughty, too... to paraphrase a friend, you had an entire oak tree shoved up your ass. But now? I'm looking at you and I... I just pity you. Because you were never God's Favorite. You were just a part of His story, a tiny part of His story. You weren't even a star. At least Lucifer knew that God can't be trusted. But I guess he was always the smart one. See the truth for yourself."
===15.09 The Trap===
:"You didn't give me a choice. You couldn't forgive me. And you couldn't move on. You were too angry. I left, but you didn't stop me."
Dean and Castiel try to contact Eileen and Sam before they travel to Purgatory to retrieve a leviathan blossom, however they soon realize that Chuck has captured them. Dean tracks Eileen's cell phone to the Lucky Elephant casino in Milford, Nebraska, but Castiel insists that they need to go to Purgatory. Dean shoots him down, but he yells at Dean for being so stupid as they don't have anything that can hurt Chuck and finishing Michael's binding spell takes priority.
Upon passing through the portal, Castiel states that he never saw a blossom during his time in Purgatory, meaning it's the only flower in the realm. They manage to capture a leviathan and force it to reveal where they can find the blossoms, which grow out of the soil when leviathan die. He also reveals that Benny was killed by his fellow vampires after helping Sam and Bobby out of Purgatory. While en route, Dean mourns Benny's death and Castiel remembers how he unleashed the leviathans into the world and continues to regret his past mistakes. Dean says he knows that Castiel is sorry about Belphegor and Mary's deaths, but Castiel clarifies that he is talking about Jack. He tells Dean that he already apologized but Dean refused to hear it because he was too angry to care about his friend. He left, but Dean didn't stop him.
The trio arrive at a leviathan graveyard riddled with blossoms and skeletons. However, the area is guarded by an angel trap. The leviathan reveals that they plan to take them to Eve so she can have revenge for killing her and her alphas. After Dean gets knocked unconscious, Castiel offers to go peacefully in exchange for sparing Dean. They take the angel and destroy the blossoms. Dean wanders around Purgatory to find Castiel, but with only minutes left before the portal closes, he stops and starts praying. He admits that he should have stopped Castiel from leaving, but he didn't because venting his anger was easier than admitting that he was wrong about everything that happened when Mary and Jack died. He says he can't control his anger when it comes out, no matter how much he wants to. He tells Castiel that he does forgive him for everything that happened. He apologizes for taking so long to tell him and hopes he can hear him. Meanwhile, Castiel has located a leviathan blossom and manages to fight off the leviathans and escape. He makes his way to Dean in the nick of time. Dean tries to apologize face to face, but Castiel says he doesn't have to, having received his prayer.
They arrive at the Bunker and start putting the spell together, and Castiel mixes his blood into the mix as Dean cannot carry the Mark a second time. They make their way to Milford to save Sam and Eileen, but Chuck forces Eileen to attack them. They pass the orb to Sam, who, after having seen what would happen if they trap God, drops the orb and allows Chuck to crush it and heal their wounds from the Equalizer. Chuck makes His leave after Dean tells Him that they'll never give Him the ending He wants.
At the Bunker, Sam explains why he couldn't trap Chuck, and Dean says it's good enough for him. Castiel says that Chuck may be gone, but He'll be back.
===15.11 The Gamblers===
:"Agent Watts is working a case in Alaska. This is Agent Lizzo."
===15.12 Galaxy Brain===
:"I knew it, Dean. When I was with Jack’s mother, she… You know, Kelly just had faith that Jack would be good for the world, and I felt it, too. I knew it. And then, when everything went wrong, and God took him from us… I was lost in a way I’ve never been before. Because I knew the story wasn’t over. I knew Jack wasn’t done. And I was right."
===15.13 Destiny's Child===
:"This is not a social call. I am here fulfilling a request ordered by Death herself. And I understand that you and she are working together."
===15.15 Gimme Shelter===
:"No. I watched you die once and I will not do it again."
===15.17 Unity===
:"Sam. Stayed behind to find another way, huh? I would've done the same."
===15.18 Despair===
:"I know. I know how you see yourself, Dean. You see yourself the same way our enemies see you. You're destructive and you're angry and you're broken. You're -- You're "Daddy's Blunt Instrument." And you think that hate and anger that's -- that's what drives you. That's who you are. It's not. And everyone who knows you sees it. Everything you have ever done, the good and the bad you have done for love. You raised your little brother for love. You fought for this whole world for love. That is who you are. You're the most caring man on Earth. You are the most selfless, loving human being I will ever know. You know, ever since we met, ever since I pulled you out of Hell, knowing you has changed me. Because you cared, I cared. I cared about you. I cared about Sam. I cared about Jack. I cared about the whole world because of you. You changed me, Dean."
===15.19 Inherit the Earth===
:"Dean, I'm here. I'm hurt. Can you let me in?"
When Dean meets up with Sam and Jack, he is forced to tell them that Castiel summoned the Cosmic Entity, which absorbed him into the Empty along with Billie. Jack is particularly distressed by Castiel's death, calling out to him while Sam and Dean investigate the bar.
In the Bunker, Dean receives a call from his cell from Castiel. He tells Dean that he's hurt and asks him to let him in the Bunker. But when Dean opens the door, it's revealed that it was Lucifer imitating Castiel's voice to trick them into letting him in the Bunker.
===15.20 Carry On===
Outside of Harvelle's Roadhouse, Bobby Singer reveals that Jack resurrected Castiel again, telling Dean that Castiel helped Jack to reshape Heaven for the better.
==See also==
* Castiel (Apocalypse World)
* Casifer
* The Castiel Song
* Castiel's Cell Phone
* Castiel's Hair
* Castiel's Handprint
* Castiel's Trench Coat
* Clairestiel
* Destiel
* Godstiel
* Leviel
* Sastiel
* Team Free Will
* Thingstiel
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