Most times all we see is the outside of a thing. The casing in which it is presented, and within which we can only imagine magic occurring. On rare occasions we get a look underneath the surface. We get to see where the magic is made:
Piston heads from a V6 Ford Bronco which was rolled down a hill long ago. Somebody apparently wanted the head for themselves, and so the pistons sit with nothing against which to compress and combust. They lay now forever motionless.