Adults Are Useless: Played with. Armitage at first seems like he could be helpful when the main characters try to tell him about the dragon Ram saw, but he's killed by another dragon before he can assist.
Animated Tattoo: The dragon burned onto Coach Dawson's skin is this.
Arbitrary Skepticism: Until she sees the dragon for herself, Quill thinks that the kids are punking her, even after it takes Mr Armitage.
Broken Pedestal: Ram discovers that the football coach who he respected and wanted to win the approval of is holding an alien as prisoner to make himself stronger and is happy for people to be killed to feed it.
Curse Cut Short: Quill tells the Inspector "Whoever you are, I am going to string you up on that wall by your b..." When Armitage is reading the incident back to her in a meeting, he confesses to not even knowing what the swear words she used were.
Damsel in Distress: The female dragon could technically count as this, as she is trapped on Dawson's skin and she'll die if the image isn't kept intact.
A Death in the Limelight: Mr Armitage. After a very minor, but recurring, role in series eight of Doctor Who, and a sizeable role last episode, he's a likable comic relief foil to Miss Quill until his sudden death in this episode.
Eagleland Osmosis: The depiction of Coach Dawson's role at the school is much closer to that of an American high school football coach than the usual situation in Britain, where school sports are much less Serious Business. In the scene where Ram and Tanya encounter Dawson while investigating the scene of the cleaner's murder at night, it's explicitly said that he isn't a teacher. In Britain, hardly any school would employ someone just to coach a school team, and the role is almost always taken by one or more of the PE teachers, occasionally helped by someone who teaches a different subject that enjoys the sport. At any rate, Dawson almost certainly should be a teacher.
Enemy Within: The dragon on Coach Dawson, which he claims he can control. It turns out the people are being killed by its mate.
Evil Teacher: Coach Dawson, who is having people killed so he can feed the blood to the dragon on his skin.
Fantastic Drug: The effects of Coach Dawson's link with the alien dragons are a very unsubtle metaphor for steroid abuse. The assistant coach even accuses him of suffering from "'roid rage" before being killed.
Flaying Alive: What the Dragons do to their victims and the eventual fate of Coach Dawson, so the dragon can get its mate back and not be commanded by Dawson.
Go Through Me: Mr Armitage nobly sets himself between the students and the dragon that has suddenly materialised in his office. It doesn't end well for him.
Heroic BSoD: Ram has been hit hard by the death of Rachel last episode, as well as losing his leg, and it's making his life difficult.
Human Shield: Miss Quill uses an inspector as one when the dragon attacks, but it turns out he was a robot all along.
I Have Your Wife: When the mate of the dragon trapped on Coach Dawson comes through, Coach Dawson tries forcing it to get blood for him to drink by threatening to harm the dragon on him.
I Never Said It Was Poison: Mr Armitage is suspicious of April, Charlie and Tanya when they mention that the cleaner who is missing was female.
The Men in Black: The inspector's smart but sinister appearance, and some of the details mentioned by Miss Quill when she explains why she's suspicious of him, refer to stereotypical attributes of Men In Black in fiction and in real-world UFO mythology.
Monster Is A Mummy: It turns out the dragon is killing people on the orders of Coach Dawson, so the blood can feed his mate trapped on Dawson's skin. When Ram points out that he can just skin Dawson, the dragon grabs Dawson and leaves Earth.
No Body Left Behind: Due to this occurring in the last episode, Rachel is considered missing by everyone not in the know. Ram's declarations that she's dead is taken as an outburst from a worried boyfriend.
Pardon My Klingon: Implied. Mr Armitage remarks to Quill that he doesn't even understand some of the swearwords she used on the Inspector.
Parental Obliviousness: Averted. After an entire episode of failing in football due to his new prosthetic leg, Ram's father sees him practising and asks if his inability to play well is due to a physical condition. After everyone not present at prom night assuming Ram was distraught over his girlfriend's "disappearance", Ram finally recounts the full story to his father, who takes it rather well, and helps him train with his new disability.
Sealed Evil in a Can: The female dragon is trapped on Dawson's skin, though Dawson claims he can control her. However it turns out it's her mate who is performing the murders.
Sealed Inside a Person-Shaped Can: The female dragon is trapped on Coach Dawson's skin. However, he apparently doesn't need to be alive for this...
Sherlock Scan: Ms. Quill does one to the Inspector, leading her to eventually figure out that he isn't a normal Ofsted inspector. She's still surprised to find that he was a robot after the dragon attacks them, though.
There Are No Therapists: Averted. While there are no actual therapists, Tanya and Ram take the time to talk about their trauma. Tanya tells Ram how she deals with it to help him, and he later opens up to his father.
Thou Shalt Not Kill: Discussed. April seems to be the only one bothered by their indirect killing of the coach who was feeding people to a dragon-like alien.
Unusually Uninteresting Sight: Miss Quill is baffled by the students' lack of surprise when she tells them that the school inspector was a robot, though in their defence, they were facing down a skin-peeling dragon when she told them, so they might not have even heard her.
The Voiceless: The Inspector, who never speaks, and when Quill asks him what he writes, he writes in the notebook some more rather then answering her.
Weirdness Censor: Discussed. Charlie is surprised that everyone at school is acting like nothing happened at the prom and Tanya mentions that Coal Hill has a body count way above average.
