A spectator selects any card from the deck. They initial the face of their card, on BOTH ends.The rest of the deck is returned to the card box. The selected card is slid into the card box, so it protrudes for about half its length.

No switch of ANY KIND, this REALLY is THEIR INITIALED CARD.

You now write your initials on the card box. In the blink of an eye, your initials jump from the BOX, onto their INITIALED CARD.