When Amos, a rebellious young man in the 1930s, attempts to stop time travelers from kidnapping a girl, he learns the future is overrun by aliens -- and his future grandson will cause the invasion by contacting them. When the time travelers realize who Amos is, they hunt him down with murderous intent in order to save the future. But when their plan fails, the time travelers must offer Amos an uneasy exchange -- knowledge and wealth for his help in creating a secret refuge outside of time for the survivors of the alien attack. Their goal: to change the future before it happens.