Procedure:

1. Use any ordinary deck of cards and its case. Get a member of the audience to shuffle the cards any way they want to.
2. Tell him/her to keep one of the cards, memorize it and return the rest of the deck to you. Place the deck back in the card case, but leave the flap open.
3. Next, ask the member of the audience to put the card back into the deck any where he/she wants. While the card is being inserted into the deck, tighten the grip on the case, so the card would not be completely placed into the deck. Do not grip it too hard or the card would not be able to go in at all and they will realise the theory behind the trick.
4. Although he/she will think that the card is now completely hidden in the deck, it is actually sticking out very slightly from the rest of the deck.
5. You can now take that card out and reveal it to impress your audience.