From a borrowed, shuffled deck of cards one spectator is asked to think of a card while another spectator is asked to name a number. Could it be that the selection is now at that position in the deck? Yes it can! In as fair as can be the magician deals down to that number to reveal the chosen card.
The actual performance has been omitted from the preview as to us magicians the method might be perceptible. A layman, however, will be fooled over and over again.