As you can see in the video, Blaine walks up to a man and hands him a deck of cards, which are in a closed card box. While the man is holding the deck, Blaine asks the man to visualize a card in the deck, and imagine it turning over in the deck. The man says “ten of diamonds.”
“Check this out,” say Blaine, taking the deck from the man and removing the cards from the box. He fans out the cards. All of them are face up but one: the ten of diamonds. The man is visibly stunned.
“That is unbelievable. That is just terrific. How’d you do that? How’d you do that? It’s so mind boggling I don’t even know what to say about it.”