As the Sixth Doctor takes Charley on a journey, presumably home, Charley is stuck with a man who she can't tell the whole truth to, and the Doctor with someone who he doesn't seem to be able to fully trust.
The TARDIS lands, and the Doctor and Charley discover a body and the Doctor is promptly accused for murder.
But the victim isn't an ordinary one...
Tropes:
- Alien Among Us: Turns out loads of aliens are on Earth disguised as humans. Once someone knows the signs they are easy to spot.
- Apologetic Attacker: When Charley wrestles Maxine to the floor, she keeps apologizing.
- Arbitrary Scepticism: Despite seeing a normal man's corpse transform into an alien's corpse, Menzies' boss only seems to take the thing as a bad joke.
- Back-Alley Doctor: Dr. Aldrich is one for various alien species who hide out on Earth.
- Bigger on the Inside: Played With. The Doctor comments on Charley's lack of surprise towards to the TARDIS, noticing that her somewhat nonplussed reaction is a refreshing change from everyone commenting on how it is bigger on the inside. Charley, who was used to the Eighth Doctor's considerably larger and grandiose TARDIS control room, makes an off-hand comment on how the control room is actually much smaller than what she is used to.
- Call-Back: The Doctor mentions the aspirin being poisonous to Time-Lords.
- Cassandra Truth: Charley in particular spends several hours being held prisoner by people who want to question her about her role in a death even though she keeps telling them that the victim was already dead when she arrived (to be fair to them, she arrived in the TARDIS in a flat that was locked from the inside, which others would find hard to accept even if she felt willing to share).
- Cat Scare: Behind a closed door Charley encounters a cat.
- Dead All Along: Sam has been dead from the start. (See also Genius Loci)
- Everyone Knows Morse: Averted; though Charley has managed to send out SOS signals for a good while, it takes a while for even the Doctor to respond to them. He also mentions that (relative to the place and time) the method is antiquated.
- Friend on the Force: Menzies slowly develops into one for the Doctor, in this story.
- Genius Loci: Sam has been absorbed into the building, and can affect it. Slater plans to invade Earth this way, using his allies to take control of other buildings to provoke the natives into a disorganised state.
- Have We Met Yet?: Charley is from the Doctor's future, and tries not to tell him too much. The Doctor on the other hand, has already met Detective Menzies in the future (as established later in "The Crimes of Thomas Brewster"), but keeps this info from her.
- Ironic Echo:I'm afraid I don't remember.
- Kindhearted Cat Lover: Charley and the Doctor discover a stray cat, and he immediately takes to it (And vice versa); this is a departure from his previous incarnation. The dead mister Bailey also counts, given he was taking care of said stray.
- The Masquerade: The person killed was an alien, disguised as a human by a DNA patch.
- Broken Masquerade: Out of necessity, the Doctor brings Menzies up to speed on the aliens in plain sight. She handles it remarkably well.
- Mistaken for Murderer: The Doctor.
- Mr. Smith: Charley claims to be called Charlotte Smith when she first meets the Doctor. Later he calls himself Doctor John Smith in the station. After hearing she called herself Charlotte Pollard in a call he works out Smith isn't her real name and lampshades this by saying "Smith does sound a little fake."
- Only in It for the Money: Both Maxine and Antonia.
- Tap on the Head: How Charley gets taken out.
