Noah's Mix Up by Gene Castillon

Effect

Two packets of jumbo playing cards are shown, each having the same five animals on the faces. One packet has blue-backed cards and the other packet has red-backed cards. Two spectators are asked to each THINK of any one of the five animals. Then, behind the magician's back, they spell the name of the animals by moving cards from top to bottom of each packet. The magician then assembles the packets, mixing them up a few times and the cards are then separated into five-card packets. In one packet you have four red-backed cards with one blue-backed and, in the other, four blue-backed cards with one red-backed. SURPRISE! The two opposite color cards in each packet are the thought-of cards!