Subtitled "Surgical card through window" (because it is only licensed for use by those with a doctorate in prestidigitation), Kaos is the creation of magician Sean Beard (obviously not his real name). Beard achieved local fame in his home town with his previous creation, "Control: Surgical car through window," which pretty much was just him driving a car through a plate-glass window. Kaos is far more subtle and less likely to get tire marks on the carpet.
The magician offers a spectator the opportunity to pick a card from an entire shuffled deck of cards. The spectator thinks the offer over for a minute and then, after being urged into action by a crowd quickly growing board, goes ahead and picks a card. After showing the card to friends and passers by the spectator (hopefully) memorizes it and returns it to the deck. The card is shuffled into the deck and completely lost, with no possible way on God's green earth that it could be located by the magician unless actual, real magic is being used or the whole thing is one of those made-for-TV fakes where the magician dresses cool and everyone else is a stooge.
The magician takes the spectator over to a window that just happens to be nearby. The spectator is given the cards and told to spread them out on the window and hold them in place, as if spreading flower petals across a table and then holding on to them for dear life because the table is vertical and the petals will explode on contact with the ground.
Once the spectator has the cards spread out, the magician walks to the other side of the glass and, after showing empty hands, pulls a card through the window with great effort. With luck, it's the selected card.
Kaos makes use of a unique gimmick -- a piece of transparent plastic film that is completely transparent. The gimmick is stuck to the window before the effect begins (it clings like plastic wrap), and cannot be seen because of its transparency. The magician must take care to memorize the gimmick's exact position or risk never finding it again, forcing a situation in which the magician must end the trick prematurely with some excuse (e.g., "I think I hear my mom calling me").
As the trick begins, the magician offers the spectator a free choice of a card. When the card is returned, the magician pretends to put it back in the deck but really hides the card by means of a "back pass." For those of you not familiar with magic terms, a back pass is a move by which the magician takes a card from a spectator, passes the hand around the body, and hides it behind his back while pretending to shuffle the cards with the other hand. It's very effective. Unless someone is standing behind you. Which they shouldn't be.
The deck of cards is handed back to the spectator as the magician walks to the window. Under pretense of showing the spectator how to spread cards on glass, the magician retrieves the gimmick with the hand that is not hiding the selected card behind his back. The gimmick is also back passed and the magician, now with both hands behind the back, sticks the gimmick to the back of the card, making sure that it is precision-aligned with the card's edges.
While the spectator spreads the cards on the glass, the magician walks to the glass's other side. The card with the gimmick affixed can now be freely held so long as the transparent side is facing spectators (they can't see it because it's transparent). The magician's hands appear to be empty.
The magician now holds the card up behind the spread cards and removes the gimmick. Because of the thinness of the gimmick, the magician will have to work a bit to pull the card off of it (like trying to open one of those grocery-story plastic bags that you put vegetables in when your hands are completely dry) so no acting skills are necessary (which will be a relief, particularly to method magicians who require extensive mental preparation whenever acting is called for). As the card is pulled from the gimmick it stops being transparent and becomes visible. The crowd goes wild!
The gimmick can be slapped on the window to wait for a future performance or forgotten and left behind, necessitating the purchase of another one. (The manufacturer encourages the latter option.)
Kaos is a very flexible effect. The gimmick works perfectly on any window or piece of transparent plastic. You can make a card appear to penetrate a sliding glass door, the conference room's glass desk, a glass shower door while your sister is doing her hair, or the face plate of your brother-in-law's motorcycle helmet (while he's wearing it!) It can even be used to make a card penetrate a solid surface such as a door or wall, but this is a little less effective as spectators just have to trust you when you say you're pulling the card through.
Important tips when performing this effect:
Trivia: Kaos was named for the dreaded International Organization of Evil (active in the 1960s) KAOS.