There's a museum about [[Recap/DoctorWhoS5E3TheIceWarriors Ice Warriors]] on Deimos, one of Mars' moons. The Eighth Doctor and Tamsin sneak into a guided tour, which quickly goes wrong when the actual Ice Warriors are resurrected by an unknown force. The resident professor on the topic helps the Ice Warriors out, fully believing that they'll appreciate his dedication to them. They don't. As the Doctor and Tamsin scramble to rescue all of the tourists, the Ice Warriors come up with a plan to re-colonise Mars, their rightful home planet, and to get rid of all of the humans living there. The Doctor offers to find a new planet for them, but they're a bit cross at him, seeing as he's the one who defeated them last time and enabled human colonisation and all.
Just as the Doctor manages to get 600 people into a 500-person escape ship and plans to defeat the Ice Warriors once again, he gets a message... from Lucie Miller, who's stranded in the middle of the battle. The Doctor has to make a choice: defeat the Ice Warriors or save Lucie.
* ContinuityNod: Many to the classic series, and quite a few to the nearby "hippie holiday resort" of [[Recap/BigFinishDoctorWhoNEDAS1E5Phobos Phobos]]. Izdaal and his backstory were established in the Fifth Doctor audio ''[[Recap/BigFinishDoctorWho008RedDawn Red Dawn]]''.
* DiscontinuityNod: Professor Schooner is under the impression the Ice Warriors were an honourable and noble race. He's completely wrong. It's hard not to see this as a bit of a dig at the "Ice Warriors as Samurai" concept in the Literature/DoctorWhoNewAdventures.
* HeroicBystander: Harold, who is prepared to risk his life to save the moonbase ... but not his wife's.
* HeroicSacrifice Grenville.
* ThePasswordIsAlwaysSwordfish: Tamsin gets through a security door to the moonbase's power distribution centre by entering the password "PASSWORD".
-->'''Tamsin''': Ha! 23rd century and nothing's changed!