With their exhibited bodies now vanished, the doctor finds himself taken prisoner by Lobos,head of security for the former Morok empire who has used this planet to construct this museum to display its former glories. He fails in vain to get the doctor to reveal secrets he's learned before taking the time lord away to be embalmed in preparation for his display with his companions Meanwhile Ian has taken up arms against a couple other Morok guards while Barbara and Vicki,split up along with the rest of their companions encounter a group of native Xerons,whose people were destroyed to create this museum and of whom they are the children enslaved by the Moroks for labor there. While Barbara and Zeron Dako are gassed while trying to locate the doctor and Ian, Vicki encourages Xeron leader Tor to take up revolutionary arms against the Morok. By Vicki using her technical skills to unlock a Morok doorway with the secret code, and by Ian's taking hostage of the Morok guards they are able to rescue the doctor from the embalming process,reunite with his companions while Tor destroys the museum-ending the cycle of events and saving the lives of the doctor and his companions before giving them a parting gift of a space time visualizer from the museum.
For a reason I only partially understand,probably due to the low budget effects (typical of a lot classic Doctor Who stories) as well as William Hartnell's growing difficulty with his lines ( a result of his arteriosclerosis induced dementia so its said), this story has been maligned as the weakest of the first doctor era of the program. In terms of plot and direction, my opinion is that its actually among the stronger. Maureen O'Brien shines in particular as Vicki-a plucky young lady who often challenges the doctor with her great knowledge,and shows her bravery by encouraging revolutionary arms by the Xeron's against the Morok. The Morok are the ideal caricatures of the last remnants of a decaying and bloated imperial system-so intent on being egoist about their past glory that they are in no position to defend it effectively. In addition to William Russell's Ian getting a lot of time as the stories main action hero of course,Hartnell gets a chance to show his absurdest humor with some of the earliest indications of the doctor as a "cosmic troll" as it were-baffling Lobos and his mind reading computers with images of old time bicycles and manatees,as well as hiding from them in empty Dalek armor.