Synopsis by Hal Erickson
In the last of the "serialized" first-season episodes (future installments will be more or less self-contained), the space travelers continue to seek a means of escaping the planet before it freezes over. Nor is this the only peril awaiting the Robinson family and their pilot Don West (Mark Goddard), as witness a treacherous voyage across an inland ocean, a rogue missile, and an earthquake which threatens to entomb the Robinson children Judy (Marta Kristen), Will (Billy Mumy) and Penny (Angela Cartwright). Meanwhile, villainous "stowaway" Dr. Smith (Jonathan Harris) continues his efforts to sabotage the mission with the assistance of his booby-trapped robot. Much of the footage in this episode is lifted from the original Lost in Space pilot film, in which neither Smith nor the robot appear (in fact, both characters were initially slated to have been killed off this week, only to be "reprieved" when CBS realized their popularity potential).