The spectator selects any random card. Tear the corner and have them sign their name on it. To keep it safe, you place it inside the card box and close the lid — they can see their signed corner inside the box. Place an envelope on top of the box. When you remove the envelope, the corner has DISAPPEARED from the box! Astoundingly, it travels and REAPPEARS INSIDE the envelope! Remove it and give it to the spectator.