A spectator is given the combination to a lock which they are asked to open.
After the spectator opens the lock you now get into your restraint device (box, mailbag or chained hands behind you).
The spectator locks your restraints with your hands behind your back.
You can not see the lock but your fingers can just reach the dial.
They watch as your fingers rotate the dial back & forth attempting to dial the combination!
To their amazement you dial the correct combination and escape without even seeing the lock!
