***Purity Point!***

This secret passageway connects the topmost tower room with the one drectly beneath it. One year, the two rooms were inhabited by Risleyites named Adam and Eve. (Adam was on top).

The only problem with this secret door is that it only opens from the outside, meaning that if the person in the other room doesn't wish to let you in, you're faced with only a smooth metal wall and eventual starvation.