"" Do you know how we learn, kids?" One of the harlequin puppets had asked us in a shrill mock-voice. "We learn by hiding in the shadows. But don't try this trick at home!"
We all watched as the harlequin's face split open. I shrieked. My schoolmates shrieked. Yet there was no blood or splintered bone. What came pouring out from the crack in the puppet's wooden skull was not gore, but a tiny set of stairs. I can safely guess that at that moment the feelings of all the children present was a blend of terror and awe, which is, of course, the pinnacle of the human emotion. When the harlequin's legs began to climb the stairs, many of the children gasped. Some even giggled, perhaps because of the way the clown was whistling joyfully as it coiled up tighter and tighter inside its own head. Then, through a masterful use of slight-of-hand, the clown vanished altogether."
--The Physics of Unseen Puppeteers by Richard Gavin