They'll beg to know how you did it!
Mindboggling mentalism effect! It seems like your spectators have free will, but they can NEVER choose the correct key to open the wallet!
And this one can be done in a number of different ways! Use it with the wallet in the routine described below, or use just the padlock and the set of keys, as in the Win Or Lose Lock routine.
This trick is ingenious in the way it works. The effect is very, very strong- your audience will be talking about this for a long time to come!
The Bank Nite Keys routine: Show a zippable leather wallet. Fold up a real bill (the larger the denomination, the stronger the effect!) and place it inside the wallet. Zip the wallet closed, then secure the zipper with a small padlock. Show five keys, and assure your audience that one, but ONLY one, of the keys opens the lock. You will select four audience members, and each will choose one of the five keys, leaving you with the one last key. Announce that if any of the audience members' keys opens the lock, that person can keep the bill inside!
The keys are mixed up, each person FREELY selects and holds one key. You hold the key that was not chosen. One by one, the members try to open the lock. None of their keys work. At last, you come forward with the key that was not chosen, and THAT is the key that opens the lock! Your bill is safe with you!
You are ALWAYS in control of whether the lock opens or not. And by the way- you also choose how many keys you want to use in your routine. Use all of them, or focus on using just two or three keys. It's all up to you!
The Win Or Lose Lock routine: Use just the padlock and a few of the keys. Show three keys, and show that only one will open the lock. You mix the keys up, then let your spectator FREELY CHOOSE any one of the three keys. You can even let him change his mind and select a different one. Then let another spectator choose a key from one of the two remaining. No matter which keys are chosen, YOUR KEY (the key that your spectators did not choose) is the only key that will open the lock. Or you can reverse the effect. Show that only one key opens the lock. Let your spectator mix them up, and hold them in their hand. Without looking, you hold your hand over the keys, mentally picking up "energy", and you select one of the keys. Of course, the key you select will open the lock.