The Variable Man is a novella written by Philip K. Dick and published in 1953.

The Terran system is continually expanding, but and old alien Empire will not let humans grow any more. War ensues, and the humans are searching a way to break free from the alien's power.

The war seems to be neverending, when a man named Thomas Cole, also known as the Variable Man, enters the picture.

What is he capable of ? What are his powers, and what are his real origins ? Will he be able to change the course of the Terran's destiny ?