Updated: May 22, 2020
BEHIND THE SCENES (THE CAVE OF THE WIZARDS)
Lost in Space "The Cave of the Wizards" (Season Two January 22, 1967)
Last week, as you recall, we left the Professor and Major West making a final check of the spaceship's control system. After months of repairs, it appears the Jupiter-2 is at last ready to blast off from this forgotten world...
Dr. Smith suffers a blow to the head, making him vulnerable to the control of an alien computer. The computer eventually transforms him into an alien, draining him of human emotion and friendship for Will. Only Will's display of affection for Dr. Smith is sufficient to shake off the effects of the computer's control, but it appears to be too late for Smith and the Robot (who has been transformed into his valet "Golden Boy") to make it back to the Jupiter-2 before the Robinsons lift off.
The props in the cave include a model of the Jupiter-2 that appears to be four feet in diameter.
The Dranconian anthem was the main title from the film, "The Enemy Below," composed by Leigh Harline. It was previously used in the episode "His Majesty Smith."
Though the Robinsons were going to lift off in this episode, the condition of the Jupiter-2's electrical systems is in question. In the second episode produced (and the fourth one aired) after this one, Trip Through the Robot, Don and John have just finished rebuilding the electrical system (probably blown out in Forbidden World) and can, once reactivating it, bring the ship up to full power in preparation for an eventual lift-off. This would seem to imply that the electrical system was not in working order at the time of The Cave of the Wizards.
This was one of Jonathan Harris' two favorite episodes, the other being West of Mars.
John makes a reference to the keys of the Chariot.
At the start when Dr. Smith has amnesia, he refers to the ship as the Jupiter-2. However, the Robot had only previously called it the Jupiter.