A person selects a pack, looks at it, and replaces it in the pack. You pretend to shuffle, but really bring that card to the top. In handing the pack to one of the party for him to throw into the air, you leave in your hand this upper one. On your command the pack is thrown up, when, dashing your hand through the cards in their fall, you seem to catch one, which, of course, is that you held, and which you have worked forward to the end of your fingers.
What did you expect?