On the way to a space colony, a crisis sends the Robinsons hurtling toward an unfamiliar planet, where they struggle to survive a harrowing night.

The Robinsons start to adjust to life on a new planet following their crash landing, but unbeknownst to them, they're not the only colonists to have survived. A terrifying storm threatens everyone's safety.

Flashbacks reveal clues to Dr. Smith's past. The Robinsons contend with a new threat as the ship's fuel supply starts dropping - fast.

John and Maureen make a surprising discovery, explaining why they haven't been able to make contact with the Resolute. Judy learns the truth about the Robot's mysterious past and forces Will to make a difficult decision. Meanwhile, Dr. Smith is ready to launch a plan of her own.

The survivors work together to build a massive light tower to send a signal to the Resolute, but the Robot is noticeably absent from the group. Dr. Smith's plan takes shape as she feels her time on the lost planet is running out. Maureen makes a daring discovery.

Not wanting to panic the others, John and Maureen quietly grapple with her discovery, but Penny overhears their conversation and is anxious to share her secret. Will learns a valuable lesson as he takes responsibility for the Robot's actions, and Judy accompanies Don on a critical search for fuel that turns treacherous. Dr. Smith manipulates a vulnerable situation into one that could prove deadly.

Judy, and Don race home across the desert with their precious cargo, but an accident pressures them into making a life-changing decision. John and Maureen are dealt a heavy blow when their vehicle gets stuck in a tar pit and they're forced to confront their past transgressions. Penny does her best to comfort Will.

Just as Maureen and John start to rebuild their relationship, the Robinsons are pulled apart again when John volunteers to undertake a risky mission. Tensions run high as family members do their best to prepare him - everything comes down to this moment, their only chance at survival. But Dr. Smith has another plan that tests even her manipulation skills.

The Robinson children are forced to come to terms with the fates of their father and Don. Will and Penny seek out an unconventional energy alternative that could power the remaining Jupiters to launch into space, and Judy sets out to find Maureen who has been taken captive by Smith. But Smith won't let her go easily.

As the clock ticks down toward the Resolute's departure, the Robinsons scramble to get off the planet - and out from under Dr. Smith's thumb.