A man finds himself trapped inside a small, white, cube-shaped room. As he desperately searches for a means of escape, various quirky characters enter and leave through vanishing doors, objects appear and disappear, and the very concept of reality gradually dissolves. It’s a simple premise—perfectly suited to the teleplay format. Director Jim Henson makes the most of his hour, bombarding his hero and the viewer alike with mind-bending questions, contradictions, puzzles, and paradoxes (“You can’t even trust me! I’m a liar; I’m lying right now!”)—you, too, just might go insane by the time the end credits roll.