Visibly, it was as if a snake of fire had wriggled out from the hooded orifice of the machine. Swift beyond sight, it had run down the thin and unswerving cylinder that marked the path of the x-ray bullet. The man's head -- the brain Charles Dograr watched -- jerked backward, as if the snake had struck...it trembled a little...then fell slowly sidewise out of the disk of Charles' vision. The old gentleman, unconcernedly, began to reverse the focus. "I'm tired of practicing on flies," he remarked. Charles Dograr's breast deflated on his terror as on a ball of iron. One by one, the objects through which their gaze had passed reappeared for a moment (as the x-ray eye of the machine retrieved its path) then vanished irretrievably in the night.
Robert M. Coates
The Eater of Darkness