The pentagram room is a location in Problem Sleuth. It is notable for being the first of two rooms in the game displayed in an isometric view, the second being the Gutterpipe Projects.
The easiest way to get to the Bust Room is to complete a Quest of Spirit for one of the four kingdoms. After your spiritual journey is complete, you will wake up here.
The pentagram room has a sigil on the floor and a door leading in each of four directions. Each door is blocked by a large Bust portraying one of the four kingdoms: Elves, Weasels, Clowns or Hogs. By completing a Quest of Spirit and receiving a boon from one of the kingdoms, you can eliminate the bust that corresponds with the kingdom which granted the boon.
Once the last of the busts is eliminated in this way, the curse is lifted and anyone may travel freely through the room in any direction.