Three Card Monte

The magician displays three cards. A spectator is asked to try and keep track of the middle card after the group is flipped over and mixed. No matter how hard they try, the spectators never can find the middle card - because it vanishes from the group as soon as the cards are mixed! In its place is found another card! This is a trick that works itself. There is no sleight of hand involved. Can be performed moments after opening the package!