Four aces are removed from the deck and placed on the the table.  Three cards are then freely selected, and signed on the face.  The three cards are then placed onto three different parts of the deck.  The cards are picked up off the table spread to show only four aces.  They are then squared on t the deck, you snap your fingers spread the top portion of the each and in between the four face up aces are three face down cards, which just happen to be three three signed selections!