The Cultists' Crypt is not an official quest, but because it has similar characteristics to other small quests in the game, it will be treated in the same manner as an official but optional quest. It may take place either in Chapters II or III when Geralt finds the Letter for Knight Eric and the Lionhead Spider crypt key on a dead knight in the Sewers under the Temple Quarter.
In the Sewers under the Temple Quarter you will find a dead body of an Order knight. On his body there is a letter addressed to "Knight Eric", describing the location of a secret base of operations for the Lionhead Spider, and a key which will unlock the gate to the Lionhead Spider Cultists' lair.
The cultists' crypt is fairly well populated by fanatical Lionhead Spider cultists, jealously guarding their stashes of alchemical ingredients, jewellery and money. The crypt is also moderately rich in sewant mushrooms. There are several Aard-able stone walls in the crypt that you must break through in order to assault the cultists and claim their valuables as your own, as well as two Circle of Elements: the Circle of Lifeless Air and the Circle of Inner Fire.
- This is not an official quest, as it is not added to your journal.
- The Letter for Knight Eric is not a quest item, although the Lionhead Spider key is.
- While there is are no XP awarded for doing this quest, obviously clearing out the place does add to your total XP.