A person chooses a card out of ten card with a hole at the top of them. the magician puts the card back into the middle of the ten without looking at it. he then puts a string into the hole of the card thus conecting them and with a jerk of the string all the cards are pulled away exept the chosen card!
The trick is very simple. when you put the card back into the deck you do it from the bottom and you dont put it in all the way you actually hide the bottom of the card with your hand and when the person pulls the string it stays behind.