Pressurized
Directed by Tim Southam
Judy and Don are with the team bringing the recovered fuel back to the colonists. Don shares his discovery about Dr. Smith's identity, to Judy's disbelief and dismay. She calls home to warn her mom, but Smith picks up the call and detects Judy's suspicion. Maureen and John are analyzing Angela's gun to figure out where it came from, and discover that their own printer made it. Will confesses that the Robot gave him the gun. To throw off the trail, Smith spins another story directing suspicion towards Victor.
Maureen and John leave to confront Victor, asking Penny to look after Will and not sneak off. On their way to the Jupiter 4, Maureen and John see a seismic rift tearing up the ground in front of them. They desperately reverse off the path, crashing into a tar pit, with their communications damaged.
Judy's team has also run into a problem. Their path is blocked, forcing them to resort to a desperate crossing of the volcanic geyser field. They carefully time the trip to the intervals between eruptions, but along the way the tanker's coupling is damaged. Evan climbs out to repair it, and succeeds, but they are just barely too late. An explosion strikes the tanker, knocking it over and crushing Evan. Worse, the tanker is punctured and can't be lifted without spilling the fuel. Judy is forced into a terrible choice: she saves Evan, over Victor's objections.
Dr. Smith tries to repair the robot, reasoning that if she can do so, it will obey her, just as it obeyed Will when he rescued it, but is unsuccessful. Meanwhile, Penny is trying to cheer up Will, even passing up an opportunity to "sneak out" with Vijay. She gives him a ride on the Jupiter's armature and helps him build a toy model of the Robot.
John tries to rig a makeshift grappling hook to pull the Chariot out of the tar, but before that plan can bear fruit, it sinks beneath the surface. They're now truly trapped, and if Maureen can't rig a makeshift radio, only one of them can escape, using the single spacesuit. John confesses to Maureen that he regrets most of all not being there for his kids — and her, and the two tearfully reconcile as they prepare for him to sacrifice himself so she can survive. At the last second, Maureen realizes that they can use the high-altitude balloon (from "Transmission") as an escape tunnel, by pressurizing it with helium. This desperate plan works, and they share a relieved embrace, amplified by their helium-pitched voices.
Judy's team is returning in somber silence. Evan remains in critical condition and the fuel is almost gone; there's barely enough to launch a single ship. Then Evan dies, Judy's first experience of losing a patient. When they reach the Jupiter 4, Vijay loses his composure and breaks Penny's confidence, revealing their true predicament on the planet. Victor decides to save his own family first and prepares to launch, abandoning everyone else. Meanwhile, Smith has discovered a crucial clue: the robot seems to respond to the sound generated by its own ship, recorded on Will's computer.
