The crypt in the sewers is (as the name quite obviously suggests) a crypt in the sewers of the Temple Quarter of Vizima, which is behind a locked gate. Geralt is given the key to these gates by the Con artist who hangs out by the sewer entrance every morning between 06:00 and 09:00. Inside is a fairly standard crypt, guarded by graveirs and ghouls, about a half dozen of each. There is also a nicely stocked chest in the deepest, darkest chamber, along with a campfire and a corpse.