The Mystery Key is a key in Dark Souls.
- The purpose of this key is unknown. Resembles a basic prison cell key.
In the area of Undead Parish with the sword wielding Hollows. It is down the stairs behind the Armored Tusk. The key is on a corpse near a ladder at the end of the room.
Opens the cell in Undead Parish that Knight Lautrec of Carim is trapped in.