Synopsis: The TARDIS arrives in a spaceport on Denossus, but for some reason its engines continue functioning even after it has materialized. As the Doctor, Jamie and Zoe explore their surroundings, a young woman named Anna attempts to destroy the shield generator in the centre of the spaceport, but only manages to attract the attention of the Vortexians who now rule Denossus. The Doctor tries to intervene on her behalf, but the Vortexians politely arrest him and sentence him to five seconds in the speculum -- an ordeal which normally destroys the victim's mind. Anna's father-in-law, Max, explains to Jamie and Zoe that the Vortexians sealed off the planet from the rest of the Universe twenty years ago, and have ruled it ever since; his son, Anna's husband Luther, was recently placed in the speculum for attempting to destroy the shield generator. The Doctor, however, survives the speculum, and recognizes the force within as the Time Vortex -- which leads him to realize where they really are.
Upon being released by the Vortexians, the Doctor and his friends set up a trap for them, and catch them in mid-transit when Anna lures them by trying to destroy the shield generator again. While the Vortexians are trapped, the Doctor switches off the shield generator's holographic sky- projection to reveal that the spaceport has in fact been removed from real space-time altogether and suspended in the Time Vortex. The Vortexians intend to unite all races in harmony under their rule and had transplanted Denossus into the Vortex as a test of their abilities. They break free of the Doctor's trap and attempt to arrest Anna, but Max deliberately shouts a racial epithet at them, causing them to administer a shock to his nervous system as punishment. But his aging heart can't stand the shock and he dies, telling the Doctor he knew what he was doing. The Doctor points out that the Vortexians have broken their own moral code by killing Max, and the Vortexians punish themselves by restoring Denossus to its place in the Universe and departing.
Notes: This is the only Second Doctor original story to appear in the regular run of DWM (although he also appears in the Summer 93 special). It's also one of only two known Second Doctor stories originally created and published after 1970.
The monsters, the Vortexians, were created by Paul Fisher, winner of Doctor Who Magazine's Design-A-Monster competition.