As the Resolute prepares to depart the system, Smith orders Maureen to leave the planet... even though John and Don are stranded somewhere in space.

While Judy sets out to find her missing mother, Will tries to contact John, insisting that his father isn't dead. Meanwhile, the colonists find a fuel source, and Smith tries to reassemble the Robot.

The colonists realize that they only have enough fuel to launch one Jupiter... if Maureen can find a way to lighten the load enough. Meanwhile, Smith continues to prey on the Robinson's minds even though they've locked her up.

While Smith tries to reassemble the Robot, Penny helps Will with a model, John and Maureen go after the Chariots, and Judy deals with losing her first patient.

Don tells Victor that he knows where they can find fuel to escape the planet. Meanwhile, Maureen debates the ethics of telling the colonists about the planet's impending destruction, Smith continues sowing dissent against the Robot, and Penny takes Vijay for a swim.

Under Victor's direction, the colonists build a light tower to signal the Resolute visually. Meanwhile, John learns what Will did with the Robot, and Maureen discovers that the planet is in danger.

The Robinsons contact another stranded family, the Watanabes. While they explore a piece of wreckage with Don's help, the Robinson children set out to hide the Robot when they discover more colonists are on the planet.

While trying to blend in with the Robinsons aboard Jupiter 2, "Dr. Smith" remembers what led her to join the colony mission to Alpha Centauri. Meanwhile, the family deals with an infestation of fuel-eating eels.

Don and "Smith" land on the planet and find another survivor. Meanwhile, John, Maureen, Will and the Robot go to investigate the Robot's ship, and Will learns more of the Robot's origins.

The Robinson family find themselves crashing on an ice-covered planet after their colony ship, the Resolute, is destroyed. Now the family must survive with the help of an unforeseen ally.