Reverse The Card
Start by putting one card face up on the bottom of a face down deck. Spread the cards like a fan, and have a card chosen and memorized by a spectator. Make sure they don't see the face up card at the bottom.
While they are looking at their card, turn the entire deck over. This will show a face down card on top of a face up deck, which will look as if the cards are all face down. Square up the deck and have the spectator put their card, face down, anywhere in the middle of the deck. Be careful not to move the top card and expose the face up cards underneath. Put the cards behind your back and turn the top card back over. Bring the deck out again. Show the spectator that their card has magically turned face up in the center of a face down deck.
If you practice, you can find other ways of turning the card over, besides putting the deck behind your back. One way is to start the trick standing up. After the card has been put back into the deck, drop your left hand (with the deck in it) to the side of your body. With your thumb, push the top upside-down card to the right as if you were going to deal it. Brush the deck downward against your leg. The top card will hit your leg and flip over. Practice this until you can do it quickly. You will need to do some mis-direction to take attention away from this move. (Have someone spill a drink, sneeze, etc.) Or you may prefer to do the behind the back move. Either way the trick is very confusing to the spectator.
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