A trusting young woman puts her hands in a box with a transparent top. She is participating in an experiment, but this one has the aura of a magic show. The investigators ask her to hold her hands steady between vertical blue lines. She does so, watching her hands carefully. They do not appear to move, nor does she feel as if they are moving.
The investigators flick a switch, and the box darkens on one side, obscuring her right hand. They ask her to reach across with her left hand to touch her now invisible right. She complies, but her eyes suddenly widen with alarm. All she feels with her left hand is empty space.