In a dystopian 2050, pilot Adam Reed steals his time jet and escapes through time on a rescue mission to 2018. However, he accidentally crash-lands in 2022 instead where Adam meets his 12-year-old self who is struggling with the recent death of their father Louis. Adam reluctantly enlists his younger self's help to repair his jet and reveals that he is looking for his wife, Laura, who was supposedly killed in a crash while on a mission to 2018.
Adam is chased to 2022 by Maya Sorian, the leader of the dystopian world and her lieutenant Christos who attempt to apprehend Adam and take him back to 2050. The Adams are rescued by Laura who reveals that she had escaped an assassination attempt on her and was left stranded in the past. Laura had learned that Sorian had traveled back in time and altered the past in order to give herself control of time travel and the future. Laura urges Adam to travel back to 2018 and destroy time travel, which was created by his father Louis, in order to set things right and save the future. Sorian attacks and Laura sacrifices herself so that the two Adams can escape. Chased by Sorian and with only enough power for one time jump, Adam and his younger self jump back to 2018.
In 2018, the two Adams attempt to enlist Louis' help, but he refuses out of concern for the scientific impact on the timestream. The younger Adam confronts his future self about his bitterness and anger and realizes that the source of it is his lingering pain over their father's death. As the two launch an attack to destroy Louis' particle accelerator, Louis changes his mind and joins the mission, having them instead retrieve the hard drive containing the only copy of his algorithm that enables time travel. A battle erupts between the Adams, Louis, Sorian, her younger self, Sorian's soldiers and Christos, resulting in the particle accelerator overloading. Sorian attempts to shoot Louis with an armor-piercing bullet, but the magnetic field of the accelerator instead diverts the bullet, causing it to kill the younger Sorian, erasing Sorian from existence as the Reeds flee.
With time travel destroyed and the future set right, Louis chooses not to learn of his own fate and enjoys a game of catch with both versions of his son before the Adams are returned to their own times. In 2022, Adam lets go of his bitterness and anger and reconciles with his mother whom he has been distant from ever since Louis' death. Years later, an adult and much happier Adam meets Laura in a situation mirroring their first meeting in the original timeline.