The effect is classic. The four aces are removed from the pack and set on the table. Twelve indifferent cards are also removed, three of them placed on top of each Ace. A spectator selects one of the four-card packets, and holds on to it for safekeeping.
Then the magic happens. One by one, the other three Aces visually vanish. As if bearing witness to trick photography, your spectators will swear that the Aces are melting away before their eyes!
Of course, when the spectator examines the card in his possession, he discover that they are none other than the four Aces!