Alan Jackson gets a job in the United States and Maria must prepare to leave her friends on Bannerman Road behind. This episode marks Yasmin Paige's last appearance as a regular.
Kaagh, the lone surviving Sontaran from "The Sontaran Stratagem"
plots revenge against the Earth by dropping satellites onto nuclear reactors.
- Chekhov's Classroom: Chrissie walks in right when Mr. Smith is telling Alan how to defeat a Sontaran. See below for how that turns out.
- Combat Stilettos: Chrissie jams a high-heeled shoe into Kaagh's probic vent.
- Continuity Nod: To The Sontaran Strategem in the main Doctor Who series.
- Several when Maria goes to take one last look in the attic. We see Bubble Shock and the box from Whatever Happened to Sarah Jane? among others.
- Kaagh's motivation is being able to avenge his fleets defeat from the Poison Sky.
- Not to mention all the way back to Classic Who stories The Time Warrior and The Sontaran Experiment.
- Famed in Story: Part of Kaagh's motivation since he's been disgraced by being the lone survivor of a failed campaign.
- I Don't Like the Sound of That Place: The village with the observatory is called "Goblin's Copse."
- Laser-Guided Amnesia: Subverted. Chrissie is knocked unconscious after hitting Kaagh in his probic vent and the gang just assumes she'll wake up with no memory of what happened. At the end of the episode, Chrissie reveals that she remembers everything.
- Look Behind You: "Look, UNIT!"
- Put on a Bus: Maria and Alan.