Penny and Maureen become trapped in a mysterious metal trench, and Don falls prey to a nasty toxin.

The Robinsons' dreams of a happy reunion fade when they realize something's very wrong aboard the Resolute. Smith seizes a chance to clear her name.

While Will searches for clues to the Robot's fate, John and Judy travel to the dusty surface of the nearby planet to help their fellow survivors.

John's predicament goes from bad to worse, sending Judy on a frantic race across the planet. Penny spies on Smith -- with help from an old friend.

The fast-spreading contaminant leaves Penny, Smith and friends stranded in tight quarters. Will and Maureen set out with Adler to find the Robot.

John recruits an unlikely partner to help hunt down a secret audio signal intercepted by the ship. Will begins to suspect Adler is hiding something.

While Maureen leads a mutiny, Hastings visits John to deliver an ultimatum, and Penny tries to convince Will that his Robot has changed.

Will and Penny scramble to hide the robots and figure out their next move. Meanwhile, Hastings amps up his war against the Robinsons.

The mission to save Scarecrow takes an unexpected turn, throwing the Resolute into chaos. Judy hatches a plan to get a ship to Alpha Centauri.