The magician gives a blue backed pack of playing cards to a spectator says it holds a prediction. Then he tells them that he has another deck of cards, but it's magical; it's an invisible pack of cards.

One of the audience selects a suit from the invisible deck and then he chooses any value with total free choice, for example the 6 of diamonds. The magician spreads out the blue backed deck and everyone see's that there's only one playing card face up: it's the 6 of diamonds. Then he flips the 6 of daimonds face down, revealing it's the only card that has a red back.

The Climax: magician spreads the whole deck and shows that all the playing cards now have blank faces!