Remove the lid and hold the box by the short ends in your right hand. Tap the side of the box hard against the heel of the left hand and the flap will pop open. Note: You may need to rotate the box 180 degrees and try again. Place the lid on the box to keep the flap in the open position. Set the box down on the table with the hinged edge of the flap to the left. This is important in the handling. You will need a deck of cards with red backs and a marker.
Place the box on the table (making sure to place it so the hinge edge is towards the left). Bring out the deck of cards and fan them out, holding the faces out toward the spectator. Turn your head so that you are not looking, and have a spectator freely select a card and sign it. Close the fan and hold the deck out towards the spectator. Have the spectator place their selected card back on the pack. Note: By not telling the spectator how to place the card back on the pack, they will more than likely place it on the bottom since your fingers are curled around the pack. You will know exactly where their card is. Turn your head back to face the spectator, and comment that you will shuffle the deck behind your back to try and lose their card. While the deck is behind your back, take their card and fold it in fourths, placing it in the left hand palm position.
Now, bring your right hand and left hand out at the same time from behind your back, keeping your left hand natural with the folded card palmed, and the deck in your right hand. Comment that you think you may have lost their card. Hand the deck of cards to the spectator. Have the spectator look through the cards to find their signed card. As they look through the cards, their card is not there. Point to the box, picking it up in your right hand and have them remove the lid. Tilt the box forward so they can see the folded card inside, then tilt it upright. As your right hand tilts the box to the left so the opening is facing left, the flap will close. Note: This flap is held magnetically against the side of the box so that the box can be examined without giving away its secret.
Bring your left hand up and turn your palm towards the opening of the box giving the appearance that the folded card came from within the box. Note: You may need to practice this move in front of a mirror to get the timing just right. Have the spectator take the card and open it, revealing their signature.