Unbroken by Tenyo Magic

After taking a framed mirror out of its carrying case, you cover the surface of the mirror and break it with a metal nut. You clearly show the broken mirror to the audience. There is no doubt that it is shattered into several pieces. With a magical gesture of your hand, the cracks in the mirror gradually disappear until the mirror is completely restored, with not a single crack remaining.

The spectators will have the sensation of watching a movie played in reverse as they see the cracks vanish before their eyes.