The deck is shuffled by a spectator and then handed back to the magician, who spreads through it and takes out a card, the identity of which is kept secret from the spectators. The magician then proceeds to fold the card into quarters, with the back outermost and places it into the grip of a bulldog clip. He explains that the card is a prediction.
Now the deck is spread facedown and a spectator is asked to remove a card and sign it on the card's face. The card is returned to the deck and shuffled. The magician now draws attention to the card trapped in the bulldog clip. He places the deck to one side, picks up the clip, which has been in full view the whole time and removes the folded card from it, immediately handing it to the spectator. It is unfolded and seen to be the signed card!