A spectator freely names a card (e.g. 5D) which is cut into the centre of a blue deck. The performer cuts a card of his choice (e.g. AS) into the centre of a red deck. The spectator and performer are now going to attempt to make their chosen cards reverse themselves while the packs are still inside their boxes.
Having mimed the removal and turning over of cards, the performer fans the spectator's blue deck only to discover that there is one card face up, but it's the AS! The magician then fans his red backed deck - and to everyone's surprise, the only face-up card in that pack is the one freely chosen by the spectator - the 5D! This seems all quite impossible but there is more to come.
Sliding the AS out of the spectator's blue deck, the performer slowly turns it over to reveal that it has a red back! That is because this is not the AS from the blue deck, but it is the actual AS that moments before was seen to be in the performer's red deck! And, even more incredibly, when the 5D is slid from the performer's red deck and turned over, it is seen to have a blue back - that's because it is not the 5D from the red deck but the actual one chosen moments ago completely free from the blue deck of cards. That's certainly impossible.
But there's still more ... if the red-backed AS found face up in the blue deck really is the one seen moments before in the performer's red deck, there won't be any AS in the red deck. To prove there isn't, the deck is handed to a spectator who is asked to quickly run through just to check that there is no AS in the red pack any longer. And if the 5D really did come from the blue-backed deck, there won't be another 5D in there either, and that pack is passed to a second spectator to look through just to check.
After a few moments, both spectators confirm that what the performer has just stated is really true, and so the AS really did instantly jump from the boxed red-backed deck to the boxed blue deck held by the spectator, and the freely selected 5D did the same in reverse - now that really is impossible!
1st edition 2010, PDF 5 pages, video 16:37.
word count: 3030 which is equivalent to 12 standard pages of text