The spectator selects a card, then he gives you a card, then he decides whether he wants to keep the last card or take the card he gave you. When he's finished making all of his decisions, the Prediction Card is read.
It reads: I will have the Apple. You will have the Banana. In the Bag will be the Pear.
As the kicker finish you can say, "And look at that -- there really is a pear in the bag.", then reach into the gag and pull out a PEAR!