he performer shows 10 marbled blocks of wood. The pieces "when solved" form a rectangle, around which a wooden frame fits exactly. As the magi try’s to solve the puzzle, he explains how he was sold the puzzle plus some expensive magic elixir, which he was told was necessary for solving the puzzle. As he continues to talk, he actually solves the puzzle fairly quickly without the elixir! However a few seconds later the magician discovers a missing piece that he forgot about! So it’s back to the challenge again.