With a stylus, you write a prediction on a small piece of paper, fold it together and put it down on the table with the stylus, in full view. Then you ask a spectator to hold a deck of cards behind his back, face down. He can shuffle the cards as many times as he wants and then, utilising the same stylus you just used put an X on the back side of the top card. Nobody knows on which card he draws this X, even less when he shuffles the deck afterwards and thus loses the card inside the deck. He returns the cards from behind his back, and fans them open on the table. The marked card is slid from between the others and turns out to be identical to the one written on your prediction!

An incredibly strong trick, which requires no form of manipulation at all.

No changes, no forcing!

A diabolical principle! Very ingenious!