The volunteer is answering questions, following, trying to look good onstage. In the midst of all this, and in a blur that no one in the audience notices, the illusionist flashes a card. This is the sleight of hand. The critical point is that the volunteer must unconsciously notice the card without the observation registering in his conscious mind. He is engaged in the banter of the illusionist, and then suddenly has a seed planted in his mind. When asked to envision a card, that choice has already been made for him.
