Thirty-nine-year-old Johnny C. Hubbel is about to make the greatest discovery in human history: that of a new planet in the Solar System. His spacecraft is approaching the vast cloud of gas that conceals—if all the calculations are correct—Planet #9. Then suddenly, it is struck by a magnetic storm and bursts into flames. Johnny watches in horror as his capsule burns uncontrollably… and finds himself at the wheel of his car, aged 19, on a narrow country road, with his girlfriend Astrid beside him and a truck heading straight toward them. He is about to relive the accident that had cost her life 20 years earlier. But this time, Johnny manages to swerve out of the path of the truck. He has saved her and changed their destiny.

Hardly able to believe it, Johnny realizes that he is about to relive those 20 years and that, in doing so, he might be able to save other people. Could he even go further back in time and save his father, an astronaut like himself, who had died when his rocket exploded?