Mind In Focus (by Trevor Duffy)

The Effect:

• The performer hands an envelope to a spectator to look after.
• He spreads cards face up, showing that they are shuffled, squares them up and turns them face down.
• These cards are unique, they have been numbered from 1 to 52.
• The spectator thinks of a number between 1 and 52, then names it aloud.
• A card is located according to the number given by the spectator.
• Finally, the envelope is opened, an exact replica of the card located by the number is found!