Step 12: Show the only cards as being Ace through Four of Spades
Address to the spectator their thoughts about how many cards you have, then swear "I only use four"
At this point CAREFULLY set the Ace of spades down on the table, being careful not to spread it so they can see two cards .. THIS TAKES MORE PRACTICE!! You don't want to hold it so firmly that it looks like you are holding a manhole cover, yet if you grip it too lightly you will lose control of the double and it will separate, KILLING your WHOLE TRICK!
Luckily, the heat won't be on this double much longer, as you are about to drop the big on on them.
As you count "2, 3, and 4" you are going to turn over the 2, 3, and 4 of spades and set them on top of the ace, forming a nice little fan of cards on the table. Done properly, it looks great and if anyone reaches for the cards to look at them it is a good idea to chop off their hand with the meat cleaver in your pocket. You do carry a meat cleaver with you when you perform magic, don't you? I do. Keeps the fingers off my cards...
And there you have it! The sequel to the World's Best Card Trick!