A deck of cards is shuffled by a member of the audience. You then riffle through the deck and let the spectator say "stop" anywhere they like. They take a look at the card they stopped at and replace it in the deck.

You then bring out the "lethal teeth" stating they will find the selected card.

The cards are dropped from the left hand onto the table and with the right hand you reach in with the teeth and attempt to catch the selected card as it drops by, but to no avail.

Once it's obvious that the teeth have failed to catch the card, the deck is given back to the spectator with the request that they find their own card the hard way.

When the spectator finds their card in the deck, everyone is surprised to see that the lethal teeth have bitten off the corner of the card! When the teeth are opened the matching corner of the selected card is found!