A super android pursues the Robinsons' friend, Verda. The terrain of the monster abounds in its chief dietary need, rubies. Dr. Smith is determined to obtain the gems despite John Robinson's rules to the contrary. When Smith, Will and the Robot encounter Idak, he is weak because he has lost his power-pack. Remembering that the rubies belong to anyone powerful enough to conquer the monster, Smith orders the Robot to restore Idak to full power. Judy and Penny meet their old friend, the lovely android Verda, who says a destruction android equipped with a homing device is after her.