Alien races appear in 25 out of 30 episodes in season two of Lost in Space, a higher proportion of episodes than in either seasons one or three. If one includes non-organic aliens such as androids and robots (I don’t; I am an organo-chauvinist), then the total would be 28 episodes. In fact, “Trip Through the Robot” and “The Astral Traveller” are the only two episodes in the second season that do not include some form of alien life (I am not counting the ghost in “The Astral Traveller” nor his uncle as aliens, for the obvious reason—they were both born on Earth). In two episodes only, “Curse of Cousin Smith” and “Cave of the Wizards,” the alien presence is either only heard (“Curse”) or implied (“Cave”).