The Killer Prediction

Lift the envelope with the card underneath it and rest it on the pile of cards. Don’t show the bottom of the envelope or you’ll give away the secret. This places the card, the ten of clubs, on top of the pile that’s on the table.

The spectator will think that the top card was a result of him mixing and dealing the cards. But you have just placed a new card, the card written on the paper in the envelope, on top of the pile.