(lexington, kentucky USA)
you have your viewer pick four RANDOM cards and you say just four regular cards and you spread them out face down and you put them together again then you show them the top card and say here is the top card and make them hold it.Now you take the second card put over the card they are holding and you put the other two face down below their card and you bring both cards that are below up and you pull the cards away after a magic slap and you tell them to reveal the card.
the secret is when you pull up the top card you do a double lift and bring up the second card on top and you give them the top card be sure not to give them two cards or else it will reveal the trick!!!If you do it right then the card they're holding is the changling! and when you pull the cards away after the magic slap and the double lift card should be on the bottom.