En route to a new colony Jupiter 2 crash-lands in an alien wilderness, leaving the Robinson family fighting for survival. After Judy becomes trapped under the ice, John and young Will go in search of a way to free her -- and find far more than they could have imagined.
After John and Maureen take Will and the Robot into the valley to search for other Jupiter survivors, Penny must put her life on the line to rescue them from an approaching storm. Meanwhile Dr. Smith crash-lands with Don West, who helps her to survive in a barren wasteland.
As Dr. Smith continues to work her way into the Robinson's good graces, a new crisis emerges when the ship begins to lose the fuel needed to escape the ice -- and an alien creature is discovered on board.
When Maureen, John, and Judy go in search of other survivors the others establish a base camp. But after Judy learns of the Robot's likely involvement in what happened to the Resolute, Will goes to great lengths to protect his friend.
The survivors pool their resources in an attempt to signal the Resolute, while Maureen enacts a plan of her own. While Will struggles to tell his father the truth, Dr. Smith must maneuver herself out of Don's crosshairs.
While John tries to convince the others to allow the Robot to stay, Dr. Smith manipulates a survivor to lash out. Penny looks to get closer to Vijay, as Don and Judy join an expedition to retrieve desperately needed fuel from a crashed Jupiter ship.
An accident leaves Maureen and John trapped in a sinking vehicle, while elsewhere Judy and the others must cross a deadly field of geysers in order to deliver the recovered fuel supply. Back at the Jupiter Penny tries to cheer up Will, and Dr. Smith plots her next move.
Desperately low on fuel, Maureen leads the survivors in a plan to launch a Jupiter stripped down to only the most essential components. As the noose tightens around Dr. Smith and her secrets, John is forced to put his life on the line to save his family.
Judy attempts to locate Dr. Smith, who has taken Maureen to the alien spacecraft in a bid to escape the planet. Meanwhile Will and Penny join the others in an effort to recover a potential new fuel source from a dangerous cave.
With Smith in control of the Robot the Robinsons prepare to break orbit -- but Maureen's plan to rescue John and Don may prevent them from a rendezvous with the Resolute.
