A 回転する床 attached to a 回転する天井, each threatening the other with 鋭い alternating spikes. This is Jacob's new 家庭, There be many more chances to see the inner rooms of this open-walled castle. The 鋭い stalagmites each have a specific set of numbers associated with them. This topography could even be a demographic 地図, showing the fate and lifestyle of previous cave-wanderers.