The Jupiter 2 receives a radio transmission from the Zenian Galaxy. It’s a call for help asking if there is a doctor available. Dr Smith responds, using the ship’s spacepod vehicle to travel down to the planet.
Smith introduces himself to the aliens on the planet as “Dr Zachery Smith” and the robot as his male nurse. The aliens explain their leader requires brain surgery. Dr Smith explains he is not a medical doctor but rather a doctor of ‘Intergalactic Environmental Psychology”.
The aliens insist he goes ahead and operates anyway, warning that if their leader dies, Smith’s “time will also be ended”. When Dr Smith protests, saying he faints at the sight of blood, he is ordered simply to “Scrub up”.
The Robinsons land the Jupiter 2 on the planet in order to retrieve Smith. They are immediately attacked and captured. When told that Dr Smith is about to operate on their leader, Don remarks – “Smith couldn’t cut an overgrown toe-nail let alone operate on anyone”.
When Smith is shown the patient he must operate on, it turns out it is a machine. The aliens claim it is not a machine but “the greatest brain in the Universe”. When the time comes, Smith runs away, saying “I can’t do it”. He is placed in the same prison cell as Don, John, Will and the robot.
It soon comes to light that the robot has the skill and knowledge to proceed with the operation on the alien’s leader. He refuses to operate however, claiming he knows the machine’s brain will be used by the aliens for evil.
The aliens force the robot’s hand by threatening the life of Will. The robot reluctantly agrees to operate. Before he does he receives a pledge from the evil brain that it will ‘mend its ways if repaired’.
Prior to the operation, Smith tampers with a device the aliens use to control time. He is reverted back to being 9 years old again. Following the successful operation, the newly restored mechanical leader of the aliens uses it’s power to restore Dr Smith back to his old self.
Actor Grant Sullivan (1924 – 2011) played the role of the head alien, identified only by the number on his silver uniform, #764. Sullivan was a meteorologist in the United States Navy during WW2. He appeared on Broadway in AUNTIE MAME in 1956 before moving to television roles.
Grant Sullivan’s big break came when he was cast in the starring role as investigator Brett Clark in the television series PONY EXPRESS (35 episodes/ 1959 – 1960). For the role he trained to ride horses. Sullivan left acting in the early 1970s and worked in real estate until retirement.