A bill is secured in a plexi glass frame and a padlock is snapped shut through the frame. 3 keys are shown to the spectators. The magician demonstrates that one of the keys can open the padlock and he mixes it with all the other keys. Two volunteers are given a free choice of key leaving one key to the magician. They are told that if their key will open the lock they will win a prize. Before each volunteer opens the lock, he gets an option to change his key with the magician's key. Each one of the volunteers tries his key to open the lock but only the last key that is left to the magician opens the lock, leaving the prize with the magician!