After a fortnight of Sontarans and battlefields, Series 4 puts its feet up and does something entirely frivolous — and gets away with it completely. “The Unicorn and the Wasp” is a full-blooded Agatha Christie pastiche with a giant alien wasp in it, and it commits to both halves of that sentence with total sincerity. It is silly, it is beautifully dressed, and it is very funny indeed. Not a classic, but an absolute pleasure.
A Body in the Library
The TARDIS lands at Eddison Hall in Surrey in December 1926, in the middle of a garden party, and the show immediately starts ticking off the checklist. There’s a grand country house. There’s a crumbling aristocratic family with a secret. There’s a colonel in a wheelchair, a vicar, a lady’s maid who knows too much, a flapper with a suspiciously fluid accent, and a footman with something to hide. Within twenty minutes somebody is dead in the library with a length of lead piping, and everybody in the room has both a motive and an alibi.
The house is stuffed with exactly the right sort of people. Lady Eddison presides over proceedings with the brittle graciousness of a woman guarding something enormous; her husband is a colonel confined to a wheelchair with rather more mobility than he chooses to advertise; her son is conducting an affair he cannot possibly acknowledge; the lady’s maid knows every secret in the building and voices precisely none of them. Everyone present is lying about something, and — in proper Christie fashion — most of the lies turn out to have nothing whatever to do with the murder.
The pleasure of it is how straight it’s played. Gareth Roberts — who did much the same trick with Elizabethan London in The Shakespeare Code — clearly loves this stuff, and the episode is packed with the specific furniture of the genre: the drawing-room gathering, the accusations flying, the flashbacks with unreliable narration, the moment where everyone’s secret comes out at once. It even does the bit where the detective assembles the suspects and walks them through it.
There’s a lovely running gag in which the Doctor and Donna keep accidentally saying Christie novel titles at each other in ordinary conversation — “murder at the vicarage,” “why didn’t they ask” — and Agatha, standing right there, keeps half-noticing. It should be unbearably smug and it somehow isn’t, mostly because the cast play it completely deadpan.
Agatha Christie, Detective
The episode’s best idea is what it does with Christie herself. Fenella Woolgar plays her not as a national treasure but as a woman having the worst week of her life: her marriage has just collapsed, she’s convinced her books are disposable rubbish, and she has no interest whatsoever in being clever for anybody. She solves the murder because she can’t help it, and she takes no joy in it at all.
That gives the froth a spine. When the Doctor tries to reassure her that her work will last, she doesn’t believe him — and the episode is smart enough to leave that hanging until the final scene rather than resolving it with a speech.
And it hangs the whole thing on a real mystery: in December 1926, Agatha Christie genuinely did vanish for ten days and was found in a hotel in Harrogate with no memory of how she got there, and never explained it. Using an unsolved biographical gap as the shape of a Doctor Who plot is a genuinely elegant move. The show fills the hole and then puts it back exactly as it found it.
The Wasp
The alien is where things get gloriously daft. The Vespiform is a giant shapeshifting wasp, and the reason it’s committing murders in the style of an Agatha Christie novel is one of the most enjoyably convoluted explanations the series has produced: a telepathic gem, a love affair in India forty years ago, a hidden child, and a psychic link that accidentally imprinted a stack of detective fiction onto an alien’s developing mind at the moment it woke up.
It makes not a great deal of sense and it doesn’t matter even slightly. The reveal — a respectable country vicar as the monster, undone by his own borrowed genre conventions — is exactly the right ending for this episode. And the resolution is neat: the gem goes into the lake, the wasp follows it, and Donna is the one who throws it. Agatha is horrified that she’s caused a death; the Doctor tells her, gently, that she didn’t.
It’s worth noting how much lighter the show’s touch is here than it was a fortnight ago. The Doctor’s Daughter closed on a dead soldier and a father who’d been quietly lied to by the universe; this one closes on a vicar turning into an insect and falling in a pond. Series 4 has been unusually willing to swing between registers from one week to the next, and it largely gets away with it because the central pairing stays absolutely constant throughout.
Detoxing With Ginger Beer
The set piece everyone will remember is the poisoning. The Doctor, dosed with cyanide, has to flush it out of his system by miming his requirements at Donna while barely able to speak — protein, salt, shock — resulting in her sprinting round a kitchen assembling walnuts and anchovies and finally snogging him full on the mouth to deliver the necessary jolt, after which he expels the poison in a cloud of gas and announces he needs to detox. It’s pure farce, brilliantly timed, and Tate and Tennant are having such an obviously good time that it’s infectious.
It also underlines what’s working so well about this pairing. There’s no romantic tension to navigate — the kiss is a first-aid procedure and both of them treat it as one, with Donna immediately complaining about it — so the show can just let them be funny together. After two seasons of unspoken yearning, the sheer relief of a Doctor and companion who bicker like siblings cannot be overstated.
It’s a very long way from the shouting bride who wanted nothing to do with any of this at the end of The Runaway Bride. Donna spends this episode thoroughly enjoying herself — swanning about in borrowed twenties evening wear, interrogating suspects with a great deal more enthusiasm than tact, and walking off with most of the best lines in the script. After the moral weight of Pompeii and the Ood Sphere, letting her simply have a lovely time at a party is a smart bit of pacing, and Tate is visibly relishing every second of it.
What The Unicorn and the Wasp Leaves Us With
Frothy, funny, and beautifully turned out. Here’s what it plants:
- Genre pastiche, done with love. Every Christie convention is present and correct, played straight, and the episode is confident enough to let the jokes come from precision rather than mockery.
- A real mystery, filled in. Using Christie’s genuine ten-day disappearance as the shape of the story is the cleverest thing here.
- Agatha as a person. Not a monument but a miserable, brilliant woman who thinks her work is worthless. It gives the comedy something to push against.
- Donna and the Doctor, unencumbered. The poisoning sequence works because there’s nothing at stake between them romantically. Best comic double act the show has had.
- A last-scene grace note. Showing her a copy of her novel still in print in the year five billion is unashamedly sentimental and completely lands.
Rating: 3.5/5 — Lightweight and entirely disposable, with a plot that collapses if you prod it, but hugely enjoyable and gorgeous to look at. Sometimes an episode just needs to be fun, and this is very fun.
A giant wasp in a vicarage, a jewel thief in a cloche hat, and a woman who didn’t know she was going to be immortal. Utter nonsense, and I loved every minute.