An intergalactic empire, the Dominators, has sent two scouts, Rago and Toba, to investigate the planet Dulkis. Their ship stops on what is locally known as the “Island of Death”, aptly named because the entire place is bathed in radiation, and absorbs the radiation for power. In a case of very bad timing, Cully, the rebellious son of the planet’s most powerful leader, Senex, shows up with his friends for seeking adventure. Going to a radiation-infested island doesn’t seem like it would be much fun, but who knows, maybe risking cancer is to Dulkians what sky diving is to humans. Anyway, the impulsive and bloodthirsty Toba has the young explorers blasted by their robots, the inappropriately adorable-sounding Quarks – except Cully, who manages to hide. Elsewhere on the island, the TARDIS lands and the Doctor happily explains they’ve landed on Dulkis, a planet whose inhabitants are pacifists, so they can take the opportunity to enjoy the beach. The Doctor realizes something is off when they discover the ruins of a house that he deduces was used for testing weapons. They’re “rescued” from the radiation by Balan and his two students. Balan explains that the island was the site of a nuclear bomb test nearly two centuries ago, before the Dulkians managed to achieve world peace. Thereafter the Island of Death was used as a site for students to learn about radiation and the cost of war. But Balan is shocked to find evidence that all traces of radiation are gone. Cully rushes into the house and tries to warn Balan, but he is skeptical. The Doctor and Jamie volunteer to investigate, and true to many of the Doctor’s investigations they wind up promptly captured.
Thinking that the Doctor and Jamie are beings native to the planet, Rago wants to test their suitability for slave labor, while Tabo just wants to kill them all. Rago wins out and tests the Doctor and Jamie’s intelligence, but they play dumb until an exasperated Rago simply releases them. Cully and Zoe go to the mainland to warn Cully’s father, but Senex is also skeptical, even with Zoe’s testimony that she and her companions are aliens, forcing Cully and Zoe to return to the island again to discover . Balan and his students find the Dominators’ craft and are captured and enslaved once Ragon becomes convinced they are “clever ones.” The slaves are set to work clearing rubble near the testing site in order to help clear the way for the Dominators to drill into the planet to harvest more energy.
Zoe and Cully manage to escape and fight back against their Quark guards. Tabo imposes his “kill him all” philosophy by destroying the test site in order to kill Cully and Zoe. This causes a power struggle between Tabo and Rago, which Tabo violently wins. Learning more about the planet, Rago goes to the mainland and terrorizes the planet’s ruling council, informing them that, because the Dominators are fighting a difficult war, the Dulkians will be used for slave labor so that the Quarks can be freed up to fight. Back on the island, Jamie manages to destroy one of the Quarks with a boulder, but they are all recaptured. Tabo kills Balan in order to try to frighten the others into giving up the name of the one who destroyed the Quark, but to no avail.
The Doctor realizes that the Dominators need to launch an atomic seed device into the core of the planet, which would trigger a chain reaction that would cover the planet with radioactive magma that could be used by the Dominators for fuel. Even though Cully and the others fail to distract the Dominators, the Doctor is still able to snatch up the atomic seed when the Dominators try to plant it. Although the volcano beneath the Island of Death is activated, the Doctor manages to put the seed device on the Dominators’ ship, destroying it when it leaves the planet. The Doctor revels in his victory outside the TARDIS, until Jamie reminds him that lava from the volcano is headed straight to the TARDIS.
The Doctor had visited Dulkis before, apparently on one of his rare uneventful jaunts.
Usually Second Doctor-era adventures have some kind of moral behind them. Here, though, it’s more than a little muddled. The Dulkians are slow to take action against the Dominators because…they’re pacifists? Cully is like the boy who cried wolf…even though he’s just adventurous in a docile society, and not ever shown to be deceptive? I get that they were trying to depict how a society that had managed to successfully adopt a pacifist ideology might react to its first hostile alien encounter, but, really, pacifism does not mean that people would blindly approach a strange spacecraft, especially after they had heard claims that there were robots out there who had killed three people.
The Dominators themselves seem to have been another attempt to replace the Daleks, especially because the Daleks could easily be copied and pasted into this story. But they’re pretty generic alien conquerors, even with the disagreements over tactics between them, and it doesn’t help that their pet robots sound a lot and look a little (head spikes aside) like adorable cartoon characters for preschoolers.
Oh well…at least it’s not just another “base under siege by monsters” story.