After a year of living alone, Jim is lonely and figures out how to wake other passengers. He deliberates his choice, but finally gives in and wakes Aurora Lane (Jennifer Lawrence), who he has already fallen in love with.
After trying everything she can, she too resolves to accept her fate - but things start to get worse on the ship. Soon, on her birthday and as Jim is about to propose, Arthur the android bartender tells her that Jim woke her up. She is furious, and they don't talk for several weeks.
Meanwhile, another pod opens - this time waking up Gus a Deck Crew Chief. He helps them access all areas of the ship, where they discover a number of major malfunctions. However, Gus is terminally ill due to the way he was brought out of hibernation. He gives them his access band, before he dies.
Jim and Aurora hurry to engineering, where they discover carnage from the earlier asteroid collision. They need to replace many parts, but the main problem is the fusion reactor which is overheating. A vent door is broken, so Jim needs to go outside in a spacesuit and close it manually.
While outside, they only way to do it is to keep the door held open. Aurora begs him not to do it, but Jim is brave and stands against the heat until he is knocked out of the ship. His suit is damaged and he is starting to lose oxygen.
Aurora hurries and puts on the other suit to come to his rescue. She pulls him inside, and to the Auto-Doc machine in the Infirmary. Using Gus's code she commands the machine to perform a full medical 'reset' on him, and Jim pulls through alive.
Soon, Jim realises he can use the Auto-Doc to put Aurora back into hibernation, but she decides to stay with him.
90 years later (well, 88 but who's counting), the crew awake and come out of hibernation. Led by Andy Garcia, they walk out to the main concourse to find a huge tree, grass, flowers, animals, and a giant tree house. (And probably an acute lack of any food, water, and 90 years of backed up poo!).