Space Ranger Buzz Lightyear embarks on an intergalactic adventure after he and his commander and crew become marooned on a hostile planet 4.2 million light-years from Earth. Determined to find a way back home, Buzz attempts a series of bold test flights to achieve hyperspace travel, but each attempt results in time dilation, causing significant jumps into the future when returning to the base. He struggles with the consequences of his time jumps, which alter the lives of his peers, especially his best friend and commanding officer, Alisha Hawthorne.

As he grapples with his situation, Buzz encounters a group of determined recruits led by Alisha's granddaughter, Izzy. Alongside his robotic companion cat, Sox, Buzz must confront a new form of threat posed by the enigmatic Zurg. Unaware of the looming danger, Buzz prepares his team for an epic battle while seeking a way to rectify past voyages and return to Earth, dealing with themes of time, loss, and the resolve to persevere against daunting odds.