Discerning the Transmundane

Hermaeus Mora is the Daedric Prince of knowledge and fate. Rather than a human form, Hermaeus Mora prefers to appear as either a swirling vortex of purple or a grotesque mass of green tentacles and eyes. His plane of Oblivion is a vast library of forbidden texts known as Apocrypha. Unsurprisingly, his Daedric artifact is book of knowledge called the Oghma Infinium, which levels all skills in one of three areas by five.

This quest is started by finding Septimus Signus inside his outpost north of Winterhold. Inside, he is studying a large Dwemer lockbox, which he says requires an Elder Scroll to see through it. He will send you off to the Dwemer ruin of Alftand to retrieve the Elder Scroll, along with an attunement sphere and a blank lexicon to give him the knowledge to read the Elder Scroll. Be prepared for the dangers that lie within Alftand as it covers a vast expanse of ground with numerous dangerous enemies including Falmer and the always deadly Dwemer centurions. Trek your way through the ruin and the treacherous underbelly of it known as Blackreach to the Dwemer puzzle. Put the lexicon its stand, solve the puzzle by pushing the buttons in the correct order, grab the scroll and the lexicon, and return to Septimus.

Septimus will require you to extract the blood of the different races of elves; the Altmer, Bosmer, Dunmer, Falmer and Orsimer. However, before you leave his outpost, you must first speak with the form of Hermaeus Mora, a purple vortex that bars your way. He informs you that Septimus has outlived his usefulness and wishes for you to take his place as champion. He will disappear and let you continue with the search for the elven blood.

Retrieving all the blood samples can take some time, but can be found by knowing which races are typically found in different factions. For example, Dunmer are typically necromancers, while Orsimer and Bosmer can usually be found as bandits in any encampment. Falmer are almost always in Dwemer ruins and all corpses can be found in various dungeons throughout Skyrim. Collect their samples and give the mixture to Sigmus, who will use the concoction to open the lockbox. Inside sits the book on a pedestal in the center of the "room." Septimus will approach the pedestal, only to get disintegrated by the Daedric Prince of knowledge. Claim his gift to you and your rightful place as his champion.

(Note: This quest will also start during the progression of the main storyline. Before retrieving the elven blood, you must be level fifteen to continue. If you return the lexicon to him beforehand, he will dismiss you and send a courier when you are the appropriate level.)