What they find, in its twisting underground corridors, is something the most cynical conspiracy theorist could never have imagined: a highly-evolved society of questing, intelligent creatures, living right under humanity’s nose for decades.
But there’s no way out of the tunnels – as the Doctor, Nyssa, Tegan and Turlough are about to discover when the TARDIS brings them, too, into the complex. It’s a rat trap – and they’ve all been caught!
Rat Trap contains examples of:
- Almost Out of Oxygen: When the complex has its bomb proof doors shut, the Doctor and the people on his side of the door slowly start running out.
- And Some Other Stuff: About the subject of dynamite:Kevin: I made it myself! A bit of nitroglycerine... Gunpowder...
- As the Good Book Says...:Wallace: The lord giveth.. and the lord TAKETH AWAY!
- Big Brother Is Watching You: As Kevin, Caitlin and Matthew enter the complex, the Rat King is observing them.
- Brick Joke:Caitlin: Who is this woman, tied up on the floor?Tegan: Turlouuugh!?Turlough: Oh. Her.
- Brought Down to Normal: The rats have a "Punishment Vaccine" that de-evolves the psychic rats back into regular ones.
- Call-Back: Nyssa is still working on a cure for Richter's Syndrome and laments needing to go home. She also mentions the events of Kiss of Death and that Turlough hasn't mentioned the events since then.
- When the Doctor is planning a trip to medieval Europe, Nyssa mentions the knights she met in Stockbridge.
- Turlough gets asked what kind of school he went to. He replies with Brendon.
- Scientist 27 asks Nyssa about the concept of revenge, and whether or not The Master who stole her father's body and killed her stepmother deserves the same.
- The Rat King says Tegan is different from normal humans, because she has the mind of a snake.
- Turlough says (and is later proven right) that the TARDIS doesn't allow weaponry because of the Temporal Grace. Guess it must break soon after.
- The Doctor says he'll call friends of his at UNIT to contact Kevin, because they're always looking for open-minded people.
- Turlough employs a charge wire from Purity Bay.
- Call-Forward: The Doctor says he adjusted a machine with Jiggery pokery.
- Chekhov's Boomerang: The spark wire from "The Whispering Forest" comes in very handy once again, though it is disposed of for good during the climax.
- Complaining About Rescues They Don't Like:Nyssa: You gave Andrews an electric shock while he was standing in water!Tegan: Don't you know how dangerous that is?Turlough: Well, don't all thank me at once.
- Crazy-Prepared: Nyssa spotted an unknown chemical compound the rats didn't want her to know about, and they refused to explain its use. She made time to synthesize it from memory just in case it might end up being useful later. Naturally, it saves the day.
- Death by Irony: The more revenge-driven rats love to apply this to human beings, including forcing them to run on treadmills like mice in cages, electrocuting them if they slow down or stop
- False Reassurance:Caitlin: You mean you turned all of the people down here into them!?Rat: No, some we killed.
- Four Lines, All Waiting: Each member of the TARDIS crew gets something different to do before coming together at the end, and they are each paired up with their own "companion" character; The Doctor with Caitlin, Turlough with Sally, Tegan with Kevin (and later Wallace) and Nyssa with Scientist 27.
- Freudian Excuse: Sally's reasons for aligning herself with the rats.Sally: No matter WHAT job, women always get looked at as if they're secretaries.
- Government Conspiracy: Matthew and Kevin are part of a group like this. Caitlin is a journalist that did a piece on them.
- Heroic Sacrifice / Taking You with Me: Dr. Wallace takes a Punishment solution into the Hive Mind of the Rat King. He fuses the lock behind him so that the Doctor can't come and rescue him.
- Hoist by His Own Petard: Sally tries to use a weapon in the TARDIS. The Temporal Grace kicks in.
- Insult Backfire: Kevin is forced to run on a treadmill and if he doesn't go fast enough, he'll get an electric shock. If he stops all together, the shocks keep coming till he dies.Tegan: That's inhuman!Rat King: Thank you.
- Lampshade Hanging:Tegan: Well, this is great, Tegan. Another cell! How do you do it?
- Long-Lost Relative: Caitlin and Doctor Wallace.
- Loophole Abuse: Turlough exploits the TARDIS' temporal grace so that he can still attack the rats; he doesn't intend to kill them with the weapon, only drive them off. If it happens to kill them anyway, well, that's just too bad.
- MacGyvering:The Doctor: I made this in 10 minutes with technology over 50 years old. Imagine if I really put my mind to it.
- Mix-and-Match Critters: Humans with rat grafts.
- The Mole: Several of the humans in the story are actually servants for the rats.
- My Brain Is Big: The rats have unusually big skulls to accommodate their giant brains and psychic powers.
- My Species Doth Protest Too Much: Scientist 27 doesn't hate humans, and doesn't wish them dead. And wishes to help Nyssa to cure Richter's plague. Only because he can.
- Non-Answer:Matthew: Doctor of what?
The Doctor: Oh, you know, this and that. Things ending in "ology", that sort of thing.
- Playing Sick: Tegan and Dr. Wallace. Dr. Wallace being old, fakes a heart attack.
- Psychic Powers: The rats can read minds, except for the Doctor's, because he's a low-level psychic himself, and delving too deep into Tegan's memories ends up being something they live to regret.
- Revenge: The rats' motivation. Just revenge.
- Revenge Before Reason: The Doctor offers the rats a chance to get out of the bunker and live peacefully on their own planet somewhere, but they are too obsessed with getting revenge on humans to even consider it.
- Rodents of Unusual Size: We don't get an exact size but when the rats are first encountered, everybody remarks on how big they are.
- The Scream: When Kevin, Caitlin and Matthew find a dead body, Kevin lets out a scream that alerts the TARDIS crew to their location.Tegan: Who screamed? Was it you?noteCaitlin: No it was him!
- Shout-Out: The Rat King is formed just like the Rat King is in The Nutcracker.
- The Doctor's plans get summarized as the plot of "The Pied Piper". Wallace's experiments on the rats were also originally called "Project Piper".
- Suspiciously Specific Denial: The rats make a big point of bringing up Tegan's memories of "the snake", and she wonders if it's because they're afraid of it. They vehemently deny it, but Tegan is no fool, and exploits their fear as part of her escape plan.
- Too Spicy for Yog-Sothoth: The rats delight in exploiting their Psychic Powers to torment humans with their own thoughts and fears, but when Tegan conjures up her memories of the Mara, it drives them half-mad with terror.
- Tunnel Network: Underneath a London castle. It's also a Cold War bomb shelter.
- You Are Number 6: The rats are designated a function and a number, e.g. Scientist 27.
- Weaksauce Weakness: The Doctornote can undo the Rat's psychic field with a dog whistle.
