Eight, Fitz and Anji find themselves in the sleepy English village of Marpling in 1931, unknowingly interrupting a stealth retrieval mission of [[MacGuffin temporally anomalous material]] by a team of TimeCops from the far future. Unfortunately, the device had already been broken, and in the prologue was set upon by a nest of angry wasps. The weapon (because of course it's a weapon) is now broken and malfunctioning in a host that is ill-suited for its intended purpose, and the wasps are wreaking gruesome havoc on the town. It's up to the Doctor, his companions, and the plucky residents of Marpling as well as the bellicose and reluctant time agents to stop the wasps before the weapon spreads its influence to the rest of the country and beyond, or face the deadly last resort to contain the threat permanently.

!!Tropes present in ''Eater of Wasps'' include:

* BlueAndOrangeMorality: Anji feels that the Doctor is demonstrating this when he seems to show more concern about damaged plums or trampled wasps than the people who have been killed, but learns that she was wrong when she sees the Doctor's refusal to kill Charles Rigby until he's sure there's nothing left of the man to save.
* BodyHorror: Not only does the cover provide ample supplies of it, the descriptions of the wasps attacking various characters are at times almost gleefully disgusting, and that's before thinking about the descriptions of Rigby's mutation.
* TheDandy: Hilary Pink, the errant younger brother of Squire Pink and the Doctor, Fitz and Anji's first friend in Marpling.
* EmpathicWeapon: It seems likely that Fat Boy was meant to be this, but the intention was lost somewhere in the execution.
* EyeScream: See: BodyHorror.
* {{Fingore}}: Ditto.
* IKnowYoureInThereSomewhereFight: The Doctor tries to encourage Charles Rigby to do this more than once, until he's sure that the original Rigby has been consumed by his 'infection'.
* IgnorantOfTheirOwnIgnorance: Kala and Jode appear to have a limited understanding of time travel, believing that there will be no consequences setting off a nuclear bomb in an English village in 1933, albeit justifying it in the name of their mission.
* LivingMacGuffin: Fat Boy is a nuclear bomb. Quite why someone decided to engineer an android nuke that is for all intents and purposes a living autonomous person until activated is never adequately explained.
* SmallNameBigEgo: Comparatively; Kala isn't exactly egotistical, but she spends most of her time believing that she knows more about time travel than the Doctor even after seeing the TARDIS just because she's a member of a professional organisation, even as the Doctor continually warns her that setting off a nuclear bomb in 1930s England will have serious consequences on history.