Abstract: A puzzle consisting of a ball bearing enclosed in a labyrinthian passageway, section of the passageway being unobscured from view by an opaque screen. A closed loop may be traced through the passageway, a section of the closed loop being obscured by the opaque screen. The object of the puzzle is to maneuver the ball bearing through the visually obscured region of the labyrinth from one end of the unobscured region of the closed loop to the other end. Solution of the puzzle requires the utilization of auditory and tactile information as the ball bearing rolls through the labyrinth and strikes the walls of the passageway. Because visual information is suppressed, negotiation of the labyrinth requires considerable visualization ability and mental dexterity, and allows for the design of challenging labyrinth puzzles with a minimum of bulk.