An Eric Lewis effect from “The Crowning Miracles”.
You show a serving tray with a deck of cards on it. Two spectators each select a card and replace them into the deck. The cards are now face down on your tray. You place a blindfold over your eyes and brandish a dagger. With much pomp you stab the dagger into the cork lining of the tray, acting as though you were absolutely sure, you would stab one of the selected cards, but you fail, the audience is laughing at you.
You try again – and – you got the first card right ! Now you have their attention! You try again – and – oh, no, it is the wrong card again, still you are full of confidence, you take your blindfold off, take bows, until you finally realize – it is the wrong card on the end of the blade… !
BUT, you show, that the blade actually has TWO cards on it. You remove the first to show that the second is, indeed, the CORRECT card!