Philip K. Dick 
The Variable Man 

In The Variable Man, Earth (The Terran System) is in a cold war with the older, corrupt Centaurian System, suppresses Terra from exploring space and expandig its borders. When a devastating new weapon called Icarus is developed by Terra, everyone expects the odds to tip in Terra’s favor. But the computers calculating these odds find an unknown variable that throws off the odds. A time traveler from 1913, known as Thomas Cole has arrived. Can this variable man from the past rescue mankind from a catastrophic future?

About the author

Philip K. Dick (1928-1982) – was a prolific novelist, essayist and short story writer – having published approximately 44 novels and 121 short stories. His works have been turned into numerous popular films, including Total Recall, Minority Report, and The Adjustment Bureau. He won a Hugo Award in 1963 for his novel The Man in the High Castle and has been named as one of the hundred greatest English-language writers by Time magazine.