"The Variable Man" by Philip K. Dick is a science fiction novella first published in 1953. Humanity is trapped within its solar system by the powerful Centauran Empire, locked in a tense cold war. When Terra develops a faster-than-light weapon that could tip the balance, their predictive machines encounter an unforeseen problem: a repairman from 1913 accidentally pulled into the future. This "variable man" possesses an intuitive genius with machines that confounds all calculations—and may determine the fate of humanity's desperate gamble for freedom.