The Stocks of Zanzibar is a classic effect, now made easy to build with Osborne Illusion plans: It's not a flimsy illusion, but rather a prop that looks the part.
His assistant steps in front of the stocks holding a cloth up and, within a matter of seconds, the cloth is dropped and the exchange has taken place. The magician is free and the assistant is locked within the stocks! It's an easy-to-build illusion that is impressive to look at, yet breaks down and can be carried in the back seat of your car.
The plans themselves are a work of art and would make a welcome addition to any workbench or library. Three pages plus instructions.