Toss an "Invisible Deck" and marker pen to a spectator in the audience. Ask him to select an invisible card and mark his selected card with a large 'X' and toss the invisible deck back to you. A real deck appears between your hands. Remove the real deck from its case and fan it to reveal the 'X' marked on the selected card. The mark is an indelible mark. Deck is fanned and none of the other cards in the deck are marked. No forces, stooges or multiple outs.