Grease Lightning

A visual transposition of the four aces and the four kings that goes like this: A spectator is asked which would they prefer, "Aces or Kings?" Whatever their choice, these four cards, let's say Kings, are cleanly inserted into separate parts of the deck and left protruding. The Aces are placed face up on top. With just a snap, the Aces visually change into Kings. The protruding cards are removed and shown to be the Aces.

In addition, Dorian tips an alternate method that will fool even magicians.