Display a wooden rod with three silks (eg. 2 Red and 1 Yellow) hanging down. The yellow silk is at one end.
You tell the audience that the yellow silk is acrobatic, it can jump from one place to the other, in which you demonstrate.
Pass the rod behind your back and now the yellow has jumped to the opposite end. Repeat this a couple of times, each time the yellow silk jumping to the opposite end. The audience realize that you are fooling them by simply turning the rod around.
They challenge you to bring the yellow silk to the middle. By hitting the silk with a magic wand, the yellow silk instantly jumps to the middle of the three silks.