The Robinsons continue their journey south where the encounter a frozen sea and drive across the ice. Back at the Jupiter 2, Dr. Smith deals with the severe cold, but just when he's about to freeze solid the temperature begins to swiftly rise. The robot computes that the planet is in a peculiar orbit around its star and will eventually become superheated. Now at risk of burning up, Smith sends the Robot to find and warn the Robinsons, but when it arrives, Major West shoots it with a laser thinking Smith sent it to harm them. West's hasty decision puts him at odds with the Professor and tempers flair along with the blazing heat wave. Heading back to the ship, the amphibious chariot must cross a now thawed and churning sea.