This trick is genius. From the Lake Tahoe book –
A card is thought of by the spectator. The performer proceeds to memorize the entire deck of cards. He proves this by telling the spectator to give him a number. He tells the spectator what card is at that number. The performer then asks the spectator the identity of his thought of card. The spectator does so and the performer tells the spectator a number. The spectator counts down to this number and his thought of card is found reversed at that point! This is the first time the thought of card is ever mentioned, and the deck is in the spectators hands.
Although the description of the effect is a little colourful – the trick pretty much appears as outlined above. When it says the spectator thinks of a card what really happens is that they spread through and remember a card and the position of that card from the face of the pack. You then shuffle and “memorize” the cards and ask for the number their card was at (say 12). You then name a card (say 7C), count down to the twelfth card from the top, and find the 7C at that position. At this point the pack is given to the spectator as you ask them the name of their card. You then name a number (say 40) and spectator deals down and finds their card face up at the position you named!
Very easy to do – the only real sleights needed are Roy Walton’s “Royverse” and a good false shuffle.
Found on page 55 of “Lake Tahoe Card Magic”. Look it up!