OK OK I have wanted to know this for half a year now... it is getting on my nerves so badly...

What is the trick called on episode 1 series 1 of Derren Brown mind control, where he asks Stephen Fry to think of a card and then Derren Ends up smoking it? It is the king of diamonds in the end.
What is this trick called?
OH and one more thing, is it a force that he makes him chose the KD or does he do it another way?
Alright, I'm being truthful here, I am looking for the method. But not for blabber to others, but for performance. I cannot deny that I am at the moment seeking the method, I know it is against rules.
