Abstract: The mechanical puzzle of the present invention includes concentrically arrangeable cylinders in which a pin projects from a first cylinder to engage with a groove which forms a maze pattern on a concentrically adjacent second cylinder. The puzzle may be solved by rotating and advancing or retracting the cylinders with respect to one another to move the pin from a starting point through a continuous passage and to an ending point. The puzzle may have multiple cylinders with multiple pin/groove pairs, may have different pin/maze arrangements, may be constructed of plastic, wood, or other material, may include secret compartments, may vary in diameter and skill level to suit users of differing mental and physical abilities, and may have interchangeable components to minimize obsolescence from user fluency.