Bastille Key is a key item in Dark Souls 2
- Unlocks doors on either side of the entrance to The Lost Sinner.
- Unlocks the door in Sinners' Rise past the water giants, on the top left path before the gate. Fire seed x1.
- Unlocks the locked door at Blacksmith McDuff
- Unlocks the cell door next to Straid of Olaphis' cell. Petrified Dragon Bone and 3x firebombs on a corpse inside the cell.
- Treasure from a body near the Upper Ramparts Bonfire in Belfry Luna (After Belfry Gargoyles). Near where Vorgel the Sinner and the dogs.
- Scholar Of The First Sin: Servant's Quarter bonfire, go to the group of boxes at the edge of the broken bridge (Where the Rupturing Hollow used to be) it has taken the place of the human effigy that was there in the regular game.