It's a flying beastie!The Doctor contrives to land the TARDIS in the middle of a runway at Gatwick Airport, narrowly missing being flattened by an incoming airliner. As the travellers scatter to avoid being arrested, Polly witnesses a murder in a hangar and is then kidnapped by the murderer, a representative of "Chameleon Tours", while Ben vanishes mysteriously. The Doctor and Jamie try unsuccessfully to convince the authorities of foul play, before discovering that a number of young people have disappeared on Chameleon Tours holidays.It turns out an alien race called the Chameleons have lost their own faces and identities due to an accident on their home planet and have been kidnapping the young people to appropriate theirs. The Doctor helps them to find another solution to their problem in exchange for releasing the human hostages.Ben and Polly discover that they have returned to Earth on the very day they disappeared, and decide to stay behind while the Doctor gets ready to depart with Jamie: but hold on - where's the TARDIS?
— Jamie meets his first aeroplane
- All There in the Manual: In the novelisation, the Director states that processed humans die and the transference becomes permanent in four weeks, explaining why the originals of the Chameleon Tours staff are left behind at Gatwick.
- Brandishment Bluff: The Doctor threatens to blow everyone to smithereens with a small rubber ball in Episode 2.
- The Blank
- Bound and Gagged: Samantha in Episode 5.
- Doppelgänger: The Chameleons' entire modus operandi.
- Freeze Ray: The Chameleons use one that looks conveniently like a fancy ballpoint pen.
- Grand Theft Me: What the Chameleons are up to.
- He Knows Too Much: Why Gascoigne was murdered and Crossland captured and subjected to Grand Theft Me.
- Imposter Forgot One Detail: Used to be called Impostor Jamie Has No Accent.
- Landmarking the Hidden Base: The aliens set up shop in Gatwick Airport.
- Meaningful Name
- Names to Run Away from Really Fast: Captain Blade.
- Newspaper-Thin Disguise: The Doctor and Jamie, to avoid pursuit. (Then the Doctor notices a Clue in the newspaper he's hiding behind, and the plot continues.)
- Nice Hat: Samantha.
- Not Quite Dead: The Doctor
- Not What It Looks Like
- Out of Focus: Considering this is their final story, Ben and Polly only appear in half the six episodes and don't feature much. Their final appearance is a pre-filmed insert. Their roles in the story are filled by Jamie and Samantha.
- Overreacting Airport Security: Inverted, since this was well before the days of metal detectors and terror alerts. If anything, the airport police are a bit too lax, since they can't even catch the Doctor and Co. when the TARDIS materializes in the middle of Gatwick's only runway.
- Plucky Girl: Samantha
- Put on a Bus: Ben and Polly are both abducted early in the story, with both Anneke Wills and Michael Craze appearing in full only in the first two episodes of the story. A pre-filmed departure scene allowed them to return for a quick goodbye at the end of the last episode. The contracts for the two actors actually ran through episode two of the following story, but it was decided to go ahead and write them out of the series.
- Anneke Wills has said in interviews that she was told that Michael Craze was being written out, but she was given the option of staying on. She opted to leave when he did.
- Rearrange the Song: The theme music's "spangles" debut in Part 2.
- Reasonable Authority Figure: Gatwick's Commandant thinks the Doctor is nuts at first, but a demonstration by the Doctor featuring one of the Chameleon's freezing pens, and an appeal from Inspector Crossland convince him to cooperate. As the facts bear the Doctor out over the course of the story, the Commandant becomes more and more helpful.