Show a large envelope with a prediction inside.
A spectator selects a card. Let's say the nine of hearts.
Proclaim that your prediction is correct! Open the envelope and remove a framed piece of transparent plastic, showing the entire deck of cards, faces on one side and backs on the other! Of course, the prediction is correct - all the cards are there! Not very impressive.
Offer to take it a step further. Ask the spectator to hold her hand above the frame and concentrate on her card.
When she removes her hand, one of the face-up cards has turned face-down! Turn the frame over, one card is face-up! The nine of hearts!! Her selected card!
And, you can hand the board out for immediate examination. They will find nothing!
Self contained. Mechanical. Nothing added or taken away. The gimmick is so clever.