The episode opens with Penny Robinson daydreaming. She fantasizes about having a special, magical past, where she was really a Princess instead of just an ordinary girl. Suddenly, a pair of sparkling slippers appears on a rock in front of her. A disembodied voice urges Penny to try them on and a long red carpet unrolls at her feet. Startled, Penny shrieks and runs away. Hearing her scream, Will dashes over to see what the matter is. He stumbles and falls onto the red carpet which rolls itself up with him inside, and then vanishes along with the sparkling slippers.
Will is transported to a spaceship where he is greeted by Captain Kraspo, and his first mate, Fedor. The Captain is upset on seeing Will, and explains that he was hoping to catch a teenaged girl. The Captain and his crew have been searching many years for “Princess Alpha,” the true heir to the planet Beta, and the only person with the power to subdue the rebellious computers that threaten to take over that world. As a baby the princess had been secreted away and hidden on Earth until such time as she could be found and brought back to rule the planet Beta. Now that Kraspo has found an Earth boy he concludes the princess must be nearby.
Kraspo asks Will if there are any thirteen-year-old Earth girls on the planet below, and Will is eventually forced to reveal that Penny fits that description. Kraspo leaves Will with Fedor and goes down to the planet to find Penny.
Meanwhile, Penny brings Dr. Smith and the Robot to where the slippers and carpet appeared to her, only to find that the objects are not there anymore. Since Will seems to have disappeared as well, they start to look for him. Smith runs into Kraspo, who asks about the Princess. Of course, Smith does not know any princesses, so Captain Kraspo decides to search for her with his telescope.
Oddly enough, the telescope leads Kraspo to the Robot. This frustrates the Captain and he starts to cry. Penny hears him, and being the sweet girl that she is, comes over to see if there is anything she can do to help. The Captain is delighted when he sees Penny and transports all three with him back up to his spaceship.
Once on the ship, Penny is taken away to a separate room. When Will tries to get Smith and the Robot to help him escape, Kraspo immobilizes the Robot and transforms the doctor into a long piece of computer tape. Naturally, this confuses Will. Fedor explains that people can easily be turned into tape, because it makes transportation easier. Will begs Fedor to change Smith back into himself again, but Fedor seems to be too scared.
Captain Kraspo visits Penny in her room. He tells her that he and his crew have long been searching for Princess Alpha, and that when they find her, they will be given a large reward. Kraspo is tired of looking and eager for his money, so he informs Penny that she must pretend that she is the Princess. When Penny refuses to play along, Kraspo changes Don and Judy into tape, and threatens to destroy them. Frightened for her friends, Penny agrees to comply and take on the role.
Since Princess Alpha’s Aunt Gamma will soon be arriving to look Penny over, Penny must be taught how to act like a princess. Apparently, the best person to teach her is Dr. Smith, so Kraspo restores him to human form again to act as an advisor. When Gamma arrives, Penny is dressed in a beautiful gown and acting very much as a princess should.
Aunt Gamma proves to be a rather nice woman. After briefly questioning Penny, she decides that Penny really is Princess Alpha and is very happy. Gamma throws Captain Kraspo in the brig for his base motives, and makes first mate Fedor the new captain. Penny is so addled by the whole experience that she herself begins to wonder if she really is not Princess Alpha after all.
Worried about his sister, Will tries to see if he can convince Fedor to stop the coronation. Much to Will’s horror, Fedor proves to be an evil computer in disguise as a human who plans to take over all of planet Beta. Will releases Captain Kraspo from the brig so he can help fight Fedor and his army of computers. During Penny’s coronation, Fedor and his gang attack. Penny tries to scare them away with her scepter, but it does not work. Luckily, Will deduces that a secret code given to the Betans when the princess was secreted away to Earth will return the real princess. Will gives the code to the Robot, who enters it into the ship's computer. Suddenly a beautiful blond girl appears who is dressed like a princess. This girl proves to be the real Princess Alpha.
Princess Alpha uses the magic scepter to chase away the computers, and to change the evil Fedor into a computer card. Happy to be reunited again, Captain Kraspo, Aunt Gamma and Princess Alpha return to their own world. Will, Penny, the Robot, Don, Judy and Dr. Smith return safely to the planet below, and all is well again.
Background information[]
- Who played Princess Alpha?
- Penny's age is given as 13 years old. In reality, Angela Cartwright was 15 years old when this episode was filmed.
- Aunt Gamma was played by Irwin's wife, Sheila Allen.
- Why were Doctor Smith and the Robot sent to “count insects?” What the heck kind of purpose would that serve?
- Why did John and Maureen go star-gazing in broad daylight?
- Why would a spaceship have a gangplank?
- How did Smith fall into that tube?
- Is it my imagination, or did captain Kraspo say "bastard" twice in this episode?? That would've pushed the boundaries on television back in the '60s.
- Why was the brig so tiny?
- Who knew you could bust a padlock open with a shoe? And bust a door lock open with a telescope??