The key to this trick is understanding it all revolves around one of your spectators being "in" on the workings. The gimmick spectator is really going to do all of the work.
Start by placing a coin into your hand and covering it with a cloth/hanky. Instruct the three spectators (with the fake one being last) to reach under the cloth and make sure the coin is still there.
In reality, the third spectator is actually going to take the coin from you, but because the cloth is so tightly wound around the coin, it leaves an imprint, creating the illusion it is still there.
Strip away the cloth to show the coin is missing.
Repeat the process, but this time the third spectator will place the coin back in your hand.
Again reveal the cloth and show that the quarter has returned. To an unsuspecting audience it will literally look like three random people, who ensured the coin was and was not there, just witnessed a coin disappear and reappear out of thin air.