Discerning the Transmundane Discerning the Transmundane is a quest available in . It serves as the Daedric quest for the prince Hermaeus Mora . It also runs concurrently with the main quest " Elder Knowledge , " and is the only other method of accessing Blackreach other than Elder Knowledge . Walkthrough . Although this quest can be started at any level , such as during the main quest " Elder Knowledge , " the second part involving the harvesting of blood can only be initiated after level 15 . It can be started by speaking to Septimus Signus , a brilliant but mad scholar who has devoted his life to studying the Elder Scrolls . He can be found in Septimus Signus ' s Outpost , an ice cave north of Winterhold . He explains that the Dwemer lockbox buried within the outpost holds the " heart of a god " and he wishes to access it to learn its secrets . He gives the Dragonborn an Attunement Sphere and a Blank Lexicon which must be inscribed with the Dwemer mechanism located within the Tower of Mzark . The tower can only be accessed via Blackreach , the underground ruins of an ancient Dwemer city . Alftand Glacial Ruins . The first step is to travel to the Dwemer ruin of Alftand , located in the snowy mountains southwest of Winterhold . Enter the Alftand Glacial Ruins and progress through the tunnels of ice . Eventually , a Khajiit skooma addict , named J ' darr , will attack . His brother ' s journal reveals that he , along with several others , were members of a failed expedition to the ruins . Proceed through the caves and past two Dwarven spiders until the Alftand Animonculory is reached . Alftand Animonculory . Proceed through the ruins and fight past the various Falmer that reside here . Several dead members of the failed expedition can be found here . Eventually , the Alftand Cathedral will be reached which grants access to Blackreach . The Alftand Cathedral . Head past the traps and Falmer who guard this section . Past a set of double doors opens into a large room patrolled by several enemies . Head through the main gate where two Dwarven Centurions can be found . One Centurion lies on the floor inactive , however , the other will awaken when approached . Defeat the Centurion and take the key from its corpse . Proceed to the next gate where a Redguard named Umana and an Imperial named Sulla Trebatius begin to fight , after a brief exchange of words . If one is killed , the other will turn and attack the Dragonborn . Proceed towards the Dwarven mechanism located in the center of the room . Activate the mechanism with the Attunement Sphere which causes the floor to retract into stairs . Head down the stairs and into Blackreach . Blackreach . Progress through the vast cavern towards the objective marker , fighting off the various creatures within . Once the Tower of Mzark is reached , near the southwest corner of Blackreach , proceed inside and through the corridors to the main room . Head up the spiral stairs until the Dwemer mechanism is reached . Place the Blank Lexicon inside the receptacle and begin the inscription puzzle . Lexicon puzzle . Solving the puzzle involves pushing four buttons on the podium in a certain order . After the Lexicon is placed on the designated receptacle , the two buttons on the right side will light up . To decipher the code , press the third button from the left a few times until the Lexicon opens and button two lights up . Press the second button from the left twice ( until the overhead lenses are seen directing light onto the sphere ) , then the first button lights up . Press this button to reveal the scroll . Pick up the Elder Scroll and the runed lexicon from the receptacle . Exit the Tower through the door beneath the button console and return to Septimus . Return to Septimus . The next part of this quest is dependent on character level . Returning to Septimus at under level 15 will cause him to dismiss the Dragonborn until he has had time to study the Lexicon . When level 15 is reached , he will send a courier to summon the Dragonborn back to the outpost . Returning to Septimus at level 15 or higher will prompt him to begin immediately reading the Lexicon . He then reveals that he is in the service of Hermaeus Mora , the Daedric Prince of Knowledge . After studying the Runed Lexicon , he explains that Dwemer blood is needed to open the Dwemer lockbox . Since the Dwemer are , blood from the various Mer races must be collected to create a facsimile . Specifically , the blood of Altmer , Bosmer , Dunmer , Falmer , and Orsimer . Septimus then gives the Dragonborn an Essence Extractor and requests that the blood be collected for him . Hermaeus Mora ' s intervention . Upon trying to leave the iceberg , Hermaeus Mora confronts the Dragonborn and reveals that as soon as the lockbox is opened , Septimus ' usefulness will be over . He then offers the Dragonborn Septimus ' position . Responding either way has no discernible consequences . Harvesting blood . To harvest the blood , loot the corpse of a deceased person with the Essence Extractor in the inventory . Blood samples can be acquired from any dead body in Skyrim . Liar ' s Retreat is one of the few locations where all blood types , except Altmer , can be found . If this location is used , then the quickest way to obtain the missing Altmer blood is from the corpse of the Altmer inside the spiked pit trap in Halted Stream Camp . The pit trap can be accessed without entering the mine itself , though it is advisable to go through the mine as falling on the spikes from above can kill the Dragonborn instantly . Other locations . The following is a list of locations that contain corpses or enemies that can be freely slain and used to harvest blood . Opening the lockbox . Once the blood has been harvested , return to Septimus . He enthusiastically asks for the extractor and presses it into his abdomen , injecting the blood into his body . He then approaches the lockbox and the locking mechanism begins to spin . A tunnel - like entrance appears and Septimus runs inside , but much to his dismay he does not find the answers he was looking for . Rather than the " heart of a god , " all he finds is a pedestal on which the Oghma Infinium sits . Amidst the confusion , he begins to levitate and Hermaeus Mora disintegrates him into a pile of ash . Approach the pedestal and take the Oghma Infinium . Upon leaving the chamber , the Wretched Abyss appears again as a manifestation of Hermaeus Mora . He greets the Dragonborn as his Champion and an option is presented to agree or disagree with his assertion . Again , either answer has no consequences . After the conversation is over the Wretched Abyss dissipates and the quest is completed .