Apocrypha is the plane of Oblivion belonging to the Daedric Prince Hermaeus Mora. This plane is first seen in the skyrim add-on, The Elder Scrolls V: Dragonborn. The Dragonborn has to visit the realm as part of the main questline in Solstheim for the add-on.
Just like Hermaeus Mora, Apocrypha is constantly shifting, filled with hidden and forbidden knowledge, and dangerous to the unwary. This infinite plane of reality is dominated by an endless, roiling sea of toxic green liquid, where giant oily tentacles slither and writhe about the waves, whipping at anyone who gets too close. What little solid ground there is consists of several archipelagos and cathedral-like buildings made of heavily weathered stone, connected by constantly-shifting bridges built of greasy black metal. Several bridges and hallways even move on their own, stretching and bending like tentacles to block or allow access to other areas.
The most prominent feature of Apocrypha, however, are the vast number of books that make up Hermaeus Mora's collection. Giant stacks of books break the surface of the poisonous sea, numerous shelves that line the halls and walls are crammed to bursting with ancient scrolls and moldering journals, heaps of books and papers litter the floors, and even entire buildings are constructed from twisting stacks of books. These books are protected and maintained by the Seekers and Lurkers, who make up the majority of the inhabitants of Apocrypha.
The sky is defined by a hazy green cloud cover with a huge swirling void in the center similar to the one seen in the Soul Cairn. There are various places in the sky where what appears to be a portal is open and the ever-present tentacles are sprouting out. Hermaeus Mora himself also uses these portals when he wishes to communicate with anyone while they are in his realm and sometimes even when they are not in his realm.
The realm is very dangerous, as the black liquid is toxic and will kill anyone who happens to fall in within seconds. Even venturing close to the edge of the liquid is dangerous, as tentacles may emerge from the water to strike at the player and deal damage. The Seekers and Lurkers are also a threat. The more common Seekers are easily capable of protecting themselves and can create doubles of themselves to assist in combat, as well as being able to turn invisible and even teleport. The Lurkers, though rarer, are far more dangerous to lower-level players, dealing serious melee damage with their claws and brandishing a variety of tentacle-based attacks, including spewing out tentacle-sprouting liquid that can ensnare the player or spawning a mass of damaging tentacles from their foot.
- Apocrypha can only be reached through a Black Book, seven of which can be found on Solstheim.
- When the Dragonborn "dies" in Apocrypha they will be instantly transported back to Solstheim.
- It is impossible to travel to Apocrypha from Skyrim. Reading a Black Book will result in the ground shaking and a status message saying "A vision of Solstheim swims before your eyes and then is gone." The Dragonborn must travel to Solstheim in order to read the Black Books and travel to Apocrypha.
- Followers cannot join you in Apocrypha, but they may comment on your reading the Black Books.
- Apocrypha is an old Latin word meaning "hidden" or "secret". It also refers to parts of a body of written work, typically religious or historical texts, of unknown or dubious authenticity.
- While in Vampire Lord form, the Dragonborn can hover above the sea of toxic black liquid without taking any damage. (Dawnguard DLC Required)
- As described in The Doors of Oblivion, the realm is an endless library with shelves stretching in every direction. Every book has a black cover with no title and it's said that this is where all forbidden knowledge can be found.
- Spirits are said to roam the halls, forever searching for knowledge.