THIS trick depends on a principle that is very little known even by magicians and should he particularly noted. Hand a one-way pack, properly arranged, of course, to a spectator to shuffle. This done give him the following instructions: 'Fan the cards with their faces towards you, remove any card that you please and put it face down on the table. Close the fanned cards and place them on your left hand. Square the pack and put it on top of your card. Cut the cards and complete the cut. Finally take the pack and shuffle it again, then hand it to me.' If the reader will follow these instructions with the cards in hand he will find that the action reverses the chosen card. The final discovery of the card can be made in any way you please. You may let the spectator deal all the cards in rows and note the position of the reversed card. Cover the cards with a newspaper, observing a headline or paragraph that comes over the chosen card. Then with your eyes bandaged with a folded handkerchief it is a simple matter to stab the chosen card with a penknife. In this case you do not touch the pack from first to last and the feat is a perfect mystery.