When entering The Hall of Lost Doors, there are 4 ladders, and when you go up one, you will not be able to go back down. Each ladder leads to a small passage, with some creatures. At the end of the tunnel, you can go down a hole, and come down somewhere near the Hall of Lost Doors. Click Here to Show/Hide Spoiler Information Spoiler warning: Quest and/or game spoiling details follow. (Settings: hidden content) You need Key 4037 to enter the hall. The ladders do not take you to the place directly above them, instead: Spoiler ends here.