A house that one of two dark staircase, the staircase in front in the dark staircase, a spiral, only one side capacity and that in the closet, Buman, difficult to detect.

• 屋里有一明一暗两条楼梯，明梯在前，暗梯在后，呈螺旋状，仅容一人侧身而过，设在壁柜、布幔之后，不易察觉。