The magician displays four transparent bags and places one of them on the table. A spectator then selects a card from the pack and commits it to memory. Their selection is replaced in the pack and suddenly the magician throws all the cards at the bag on the table. The cards all scatter, except for one that's stuck on the bag...it's the chosen card.

When the spectator tries to remove the card he realizes that it's inside the bag! Immediately the magician clearly removes the card from the inside of the bag.