Casually show the cards in your hands. Make this brief. You don’t want the spectator to notice that there are only cards of two suits in your hands. Casually take the two piles of cards and mix them together. As you do this, recount the fairness of the process: the spectator mixed the cards, freely selected a card, placed it into the second pile and then mixed the pile.
You’re now "clean." The secret has been destroyed.
Ask the spectator to name his card and turnover the face down card.
