Star Trek (film)/Summary/Act Two

Cadets are assigned to ships based on their aptitude, with the most capable cadets assigned to the USS Enterprise, a ship completed so recently that it hasn't even been christened yet. Uhura is originally assigned to the , but complains directly to Spock, citing her numerous commendations and recommendations, insisting she had earned an assignment to the Enterprise. 
Spock quickly corrects that oversight. Kirk has been grounded pending a ruling on his inquiry and is not allowed to board the shuttles to join the mission. However, McCoy takes him to the medical bay, where he injects him with a vaccine against Melvaran mud fleas temporarily making him ill so that, as a doctor refusing to abandon his patient, he has an official reason to take him along on the mission. 
The Enterprise leaves for Vulcan, after a slight delay caused by the backup helmsman, , forgetting to disengage the "parking brake" before jumping the Enterprise to warp. Pike orders the Enterprises very young navigator, Ensign , to make a ship-wide mission broadcast. Chekov announces that the crew's orders are to investigate seismic disturbances and aid in evacuation of the planet if necessary. 
After hearing Chekov's announcement, Kirk suddenly realizes that the "lightning storm" is exactly the same occurrence the Kelvin encountered two decades earlier. Realizing that they are running straight into a trap, Kirk rushes through the ship to Uhura despite suffering a bad reaction to the vaccine McCoy gave him. Despite his initial difficulty to communicate coherently, he finally manages to ask her about the Klingon distress call she had deciphered earlier and she confirms that the attackers were Romulan.
At Vulcan, the Narada has lowered a drilling platform, which is boring into the planet. Ayel notifies Nero that seven Starfleet vessels are approaching. Kirk rushes to the bridge to inform Captain Pike. Pike and Spock, though initially quite skeptical, are convinced after Uhura confirms Kirk's suspicion. As they disengage warp drive, the Enterprise finds itself in a debris field of the other seven Starfleet ships which arrived shortly before they did. 
At the direction of Pike, Sulu is able to navigate his way through the debris with minimal damage. As they clear the debris, they come upon the Narada, drilling above Vulcan's atmosphere. The Narada attacks the Enterprise, which takes heavy damage. But just as they are about to fire again, Nero realizes which ship he is firing at and orders a cease-fire.
He hails the Enterprise and casually identifies himself. Pike, seeing a Romulan, accuses him of an act of war and offers to reach a settlement, but Nero states he stands apart from the Romulan Star Empire. He openly greets a confused Spock, and orders Pike to come aboard via shuttlecraft. Pike asks if there are any advanced hand-to-hand combat-trained officers on the bridge, and gathers Sulu, Spock, and Kirk for the away mission. 
Pike promotes Spock to captain and puts him in charge of the Enterprise. He also commissions Kirk as first officer, much to Spock's chagrin. Pike outlines his plan to do two things at once: on the shuttle en route to the Narada he will drop Kirk, Sulu, and Chief Engineer Olson into an orbital skydive. They will land on Naradas drill platform and disable it in order to contact Starfleet, since the drill has disabled communications and transporter capabilities. 
Pike arrives on the Narada as the three begin their descent and, despite the immediate death of Olson, Kirk and Sulu eventually manage to fire on the drill and disable it.
A Narada crewman reports the drill's incapacitation, but tells Nero that the drill reached Vulcan's core before going offline. Nero orders the launch of the "red matter", which is dropped from the ship down the hole and explodes at the planet's core. Chekov discovers what the "red matter" is doing: creating a black hole in the middle of the planet. Vulcan will be destroyed in a matter of minutes. Spock leaps up from his chair, ordering the Enterprise to signal an evacuation of the entire planet, while he himself hurries to the transporter room to beam down and evacuate the Vulcan Council, which includes his parents.
Kirk signals the Enterprise to beam him and Sulu back at the same the moment when Nero orders the Narada to retract the drill and leave orbit. The jolt causes Sulu to fall off the drill platform without a chute. Kirk leaps from the platform into a controlled dive and grabs Sulu before releasing his own chute. Unfortunately, the drag is too powerful and Kirk's harness tears loose. Kirk frantically signals the Enterprise to beam them up, but the transport chief cannot lock on to them while they are moving too fast. Chekov, however, can, and rushes to the transporter room, creating a pinpoint beam that snatches Kirk and Sulu aboard mere moments before they hit the surface.
Right after Kirk and Sulu are beamed back aboard, Spock tells Kirk that he is beaming down to save the Vulcan Council, which includes Spock's parents. Kirk tries to stop him, but he ignores Kirk and orders the transporter chief to beam him down immediately. The council members were taking refuge in the katric ark, a chamber within Mount Seleya, which they could not simply beam through. 
Two of the elders in the council are killed by falling rocks and statues, but Spock is able to get five of them outside, including his parents. As the transporter is about to pick them up, the rock his mother is standing on collapses, causing the transporter to miss her. As they re-materialize on board the Enterprise, Spock stands on the transporter pad in shock, having lost his mother, with his hand still reached out to her. The Enterprise crew retreats and watches in horror as Vulcan implodes into oblivion.
:"Acting captain's log, stardate 2258.42. We have had no word from Captain Pike. I therefore classified him as a hostage of the war criminal known as Nero. Nero, who has destroyed my home planet and most of its six billion inhabitants. While the essence of our culture has been saved in the elders who now reside upon this ship, I estimate that no more than ten thousand [Vulcans] have survived. I am now a member of an endangered species."
Kirk, Sulu, and the few Vulcans who were able to be brought aboard the Enterprise are brought to sickbay for treatment. Soon after, Spock leaves the bridge, and he is followed into the turbolift by Uhura who tries to comfort him.
Nero asks Pike for the security codes to defense systems around Earth, but Pike refuses to give them to him, disgusted by Nero's act of genocide on Vulcan. Nero speaks about how the Narada, in his time, was a mining ship, and he was laboring to support his wife, who was expecting his child, before they were killed when Romulus was destroyed. 
He placed blame on the Federation for doing nothing, and accused Spock of betraying them, promising himself retribution. Pike pleads that Romulus still exists, but Nero only knows that his world – the Romulus of the future – was destroyed, and he intends to destroy every world of the Federation, starting with Earth, so that others will know his pain. Forcing a Centaurian slug down Pike's throat, which will help coerce Pike to give out the security codes, Nero orders the Narada to continue to Earth.
On the bridge of the Enterprise, Spock reasons that the Narada must have traveled back in time from the future. He states that they must regroup with the fleet, but Kirk says that in order to stop Nero they must go after him first. This culminates in an argument which ends in Spock ordering Kirk's removal from the bridge. When Kirk physically protests, Spock incapacitates Kirk with a Vulcan nerve pinch, orders him placed in an escape pod and jettisons him off the ship. Kirk awakens to find himself on the snow-covered world of , another planet in Vulcan's system. Picking up his gear, Kirk heads for the Starfleet station fourteen kilometers away.
:"Stardate 2258.42… four uh, four, whatever. Acting Captain Spock has marooned me on Delta Vega, in what I believe is a violation of Security Protocol 49.09 governing the treatment of prisoners on board a starship."
He is chased down by a "drakoulias" which is in turn attacked by an even larger insectoid animal. It chases Kirk into a cave, and when it finally attaches a tendril to catch him, trying to consume him, it is spooked off by an elderly Vulcan man wielding a lit torch. Before he can thank his savior, the old man, who had recognized Kirk on sight, reveals himself to be Spock, Kirk's old friend, but the latter is skeptical – until the former identifies Nero as Pike's captor. Spock melds with Kirk so that he can understand why he is here. 
Spock explains that 129 years in the future, in the year 2387, an impending supernova threatened to destroy the home worlds of the Romulan Star Empire and, potentially, the rest of the galaxy as well. Spock developed a stockpile of "red matter", a substance that can be ignited to form a singularity.
However, the star exploded while he was en route, and Romulus was destroyed. Spock launched the red matter from his ship, the , to prevent further damage. Immediately, Spock was confronted by a surviving Romulan mining vessel, the Narada, captained by Nero. Spock tried to escape, but the resultant black hole captured both the Jellyfish and the Narada, creating a disturbance in the space-time continuum sending both ships into the past. 
The Narada exited over one hundred and fifty years in the past, where it confronted the Kelvin. Spock's ship entered moments later, but what appeared seconds to him was twenty-five years to Nero and the Narada. He explains that Nero captured his ship, but kept him alive, marooning him on Delta Vega, so that he could witness the destruction of his own home planet, Vulcan, just as he had to witness the destruction of Romulus. 
Kirk explains he was left on the planet by the Spock he knows, who is currently in command of the Enterprise. The elder Spock is surprised, knowing that Kirk should be in command of the ship. It is then that Spock realizes that when Nero exited the black hole and confronted the Kelvin, he altered history and created an alternate reality, which changed everything, especially Kirk's life. Kirk asks Spock whether his father lived in the original timeline. Spock confirms that George Kirk proudly saw his son take command of the , and often spoke of him as his inspiration to join Starfleet. Spock leads Kirk to the Starfleet base.
Kirk and the elder Spock are met by a short alien officer, Keenser, who leads them inside, where they meet this timeline's . A transporter genius, Scott was "exiled" to Delta Vega after beaming Admiral 's prized beagle to an unknown location during a failed experiment in "transwarp beaming". Spock informs Kirk that he must relieve the Vulcan's younger self of command by provoking him and showing everyone that Spock is too personally and emotionally compromised to lead the mission and captain the ship.
Giving Scott the formula for "transwarp beaming" – an operation originally devised by the Scott he knew – Spock, who had responded to Kirk's suggestion that he was now "cheating" by recalling the "old friend" who had taught him how to cheat, sends Kirk and Scott back to the Enterprise. Not too long after they are transported to the Enterprise (Scott had materialized in a water tank and nearly drowned), the two are spotted and eventually captured by security personnel – led by Hendorff, the very cadet who had started the bar brawl which led to Kirk joining Starfleet. 
They are taken to the bridge where an astounded Spock attempts to find out how the two were able to transport on board the ship while it was in warp. Kirk refuses to answer and recommends Scott do the same, and then proceeds to ask why Spock doesn't feel any anger or have any emotion over the destruction of his planet and the murder of his mother. He keeps pushing and provoking Spock, claiming he never loved his mother. Upon hearing this accusation, Spock finally snaps and lunges after Kirk, ruthlessly beating and strangling him to the point of nearly killing him, before Sarek begs Spock to stop. Realizing how far he has gone, Spock relieves himself of duty and leaves the bridge. Kirk assumes command and orders an immediate pursuit of the Narada.