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Recap / Doctor Who S30 E7 "The Unicorn and the Wasp"

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Quick! Someone call the exterminators! Roll out the Daleks! We need massive pest control!

Agatha: Agatha Christie.
Donna: What about her?
Agatha: ...That's me.
Donna: No.

Original air date: May 17, 2008

The One With… Agatha Christie, David Tennant's dad and a giant, blasphemous wasp. In the mansion, with a Big Damn Kiss.

Not necessarily all in that order.

Written by Gareth Roberts.

The Doctor and Donna materialize the TARDIS outside a country estate. Smelling the air, the Doctor deduces that they've landed in the 1920s. Donna retorts that the Doctor's just trying to show off and has figured out the date from the vintage car coming up the driveway.

The car's driver, Professor Peach, parks outside the estate's front entrance, having come to attend a party thrown by the home's owner, Lady Clemency Eddison and her husband Colonel Hugh Curbishley. He is promptly greeted by the butler, Greeves, just as the village reverend, Arnold Golightly, arrives on his bicycle. As the servants take their luggage, they exchange pleasantries. Peach decides to go to the library to do some research on his own before the party begins, while Golightly jokes that all this work will be the death of him.

Watching from the side of the house, Donna and the Doctor are enthused to be attending a party in the 1920s. The trouble is that they haven't been invited... but the Doctor points out that they have the psychic paper. They head back to the TARDIS so Donna can change into proper Twenties attire.

In the library, Professor Peach looks at one document and realises that he was right about something kept secret all these years. Suddenly, a shadowy person comes in, and Peach quickly hides his papers, telling the person that he was just doing some mundane research. He then asks the mysterious person what he is doing with a lead pipe. The mysterious person's eyesight becomes purple as Peach mumbles, "That's impossible!" The mysterious person, revealed to be a giant wasp, suddenly swings the piece of pipe at Peach's head as the Professor screams...

The Doctor and Donna make their way to the front lawn, Donna having changed into a flapper dress. They arrive as the guests come out and are announced by Greeves. First is Lady Eddison, who wonders who the newcomers are. The Doctor uses the psychic paper to fake an invite and comes up with a story about meeting her at an ambassador's reception. Lady Eddison excuses herself as she is being cautious because the Unicorn is about. The Doctor, at first, is thrilled about the possibility of meeting an actual unicorn... until Lady Eddison clears up the confusion by explaining that "the Unicorn" is a notorious jewel thief who is on the loose and has just struck again. Next up is Lady Eddison's wheelchair-bound husband, Colonel Hugh Curbishley, and their son Roger, who starts to hit on Donna; the Colonel has been confined to his wheelchair since 1918 due to a terrible illness. Donna is confused why Lady Eddison has a different surname from her husband and son, and the Doctor explains that the Eddison title descends through Lady Eddison, not the Colonel; so one day Roger will be a "Lord Curbishley". Roger secretly flirts with Davenport, the male servant; Donna and the Doctor easily pick up on the homosexual relationship between them and whisper quips to each other.

Next to arrive is Reverend Golightly, whom Lady Eddison congratulates on the apprehension of two thieves who tried robbing his church last Thursday night. Following him is the socialite Robina Redmond. Last to come is the guest of honour, who needs no introduction at all, British mystery writer Agatha Christie. The Doctor is ecstatic about meeting her, as she is another of his favourite authors (and he once mentioned to Martha that he was dying to meet her). He admits that he was only surprised once by her books, but "It was a good once!" Still a young writer at this point, she has recently published her sixth novel, The Murder of Roger Ackroyd. The Doctor and Donna are both impressed when she calmly notices that they're not married, as Donna has no wedding ring. Agatha is, however, unwilling to talk about her husband, who will not be joining them. Seeing that they are a person short, Lady Eddison tells Miss Chandrakala to go into the house and find Professor Peach.

The Doctor acquires a newspaper from Colonel Hugh's chair and reads it. He immediately pales as he realises that something is wrong: it's December 8, 1926, the day Agatha Christie disappeared. He explains to Donna that Agatha has just discovered that her husband is having an affair with another woman. Being British, these people would normally just carry on (with stiff upper lips), but this time, that won't happen. Tomorrow morning, her car will be found abandoned by the side of a lake; ten days later, Agatha will turn up in a hotel in Harrogate with no memory of what happened. She'll never speak about what happened until the day she dies.note  Whatever will happen, it's about to happen here today. And just what caused her disappearance becomes clear when Miss Chandrakala comes running back, yelling frantically that the Professor has been murdered in the library.

The Doctor and Donna race to the library to look at the Professor's body, followed by Agatha. The Doctor determines that blunt force trauma was the cause of death, and notes that the watch broke as the victim fell, pinpointing the exact time of death to 4:15. Agatha discreetly takes a piece of paper from the fireplace, but the Doctor notices her reflection in the bookcase. Donna thinks it strange that the professor's murder is like the board game Cluedo (The Body in the Library, with a lead pipe). The other guests arrive on the scene and decide to call the police. However, the Doctor uses his psychic paper to talk them out of it.

Agatha: Someone should call the police.
The Doctor: We don't have to! Chief Inspector Smith from Scotland Yard. Known as "The Doctor". Miss Noble is the plucky young girl that helps me out.

Donna takes issue with the Doctor calling her a "plucky young girl"note , but the Doctor defensively explains that there are no policewomen in 1926. While Agatha keeps the others in the sitting room until he's ready to question them, Donna asks the Doctor why they aren't calling the real police. The answer is quite simple: he's found morphic residue, a byproduct of shapeshifting, on the floor, meaning that one of the guests is an alien in human form. Donna is weirded out by the idea of Agatha Christie being literally surrounded by murder, comparing it to Charles Dickens being surrounded by ghosts at Christmas (not realizing that the Doctor has actually experienced just that), or finding Enid Blyton having tea with Noddy.

While the Doctor tastes the residue to determine what left it, they walk past the sitting room, whilst Donna speculates that the murder is like Murder on the Orient Express, where everyone did it. Agatha overhears this and finds the idea brilliant, Donna tries to tell her it's one of her best books, but the Doctor has to shush her that it hasn't actually been written yet, so Donna tries to take advantage of this to get it copyrighted in her name. The Doctor directs Donna to search the rooms upstairs for clues (and, he whispers, more residue), handing her a large magnifying glass, while he and Agatha talk to the suspects. The Doctor expresses joy at being able to solve a murder mystery with Agatha. She reluctantly agrees to work with him, unhappy at the Doctor's casual attitude toward the murder.

Each of the guests recount their stories of what they were doing at 4:15. Each is revealed to be hiding something, except for Reverend Golightly, who claims to have been unpacking in his room.

  • Lady Eddison claims to have been taking tea, however, she was really surreptitiously drinking alcohol from a flask.
  • Robina Redmond claims to have been using the toilet, whilst really she was in the bathroom loading a tiny pistol.
  • Roger Curbishley claims to have been walking alone, when he was actually having a tryst with his lover Davenport, one of the footmen.
  • Colonel Hugh claims he was reading military memoirs in the study to cover that he was actually viewing pornography and fantasising about can-can dancers, which causes him to slip into a second flashback. The Doctor manages to snap him out of it, much to Hugh's embarrassment.

Agatha points out that they have nothing to go on, suggesting they use "ze little grey cells". The Doctor can't help but muse about his fondness for Poirot, which then causes him to reminisce (with a funny flashback) about how he was once in Belgium long ago rescuing Charlemagne from an insane computer. Agatha thinks the Doctor is making things up since Charlemagne lived centuries ago, and chastises the Doctor for overlooking an important clue. The Doctor then sarcastically asks if it's the bit of paper he caught her nicking from the fireplace. Agatha is surprised by the Doctor having noticed this, calling him a "crafty man", much to his amusement. Agatha produces the paper she removed earlier; it obviously spells "maiden", although the "m" is missing, although neither she nor the Doctor is able to divine its significance. They hope Donna will be able to bring them more clues.

Donna has come upon a locked door during her sweep of the rooms. She encounters Greeves, who informs her that Lady Eddison has kept the room shut for the last 40 years, after spending six months in it recovering from malaria following her return from India. With Donna pulling rank on him as an investigator from Scotland Yard, Greeves has no choice but to open the door for her before leaving. Inside the room, it is barren and dusty except for a solitary child's teddy, making Donna wonder even more why it has been sealed. She then hears a buzzing from the window, commenting that the 1920s, unlike her own time, still has bees… When she pulls back the curtain, instead of a trapped and harmless bee, there is a giant (as in human-sized) wasp outside the window. The wasp breaks in and tries attacking her, as Donna backs up to the window. Donna begins yelling for the Doctor, who would know what to do against this thing. Using the magnifying glass, Donna burns the wasp with sunlight, allowing her to run outside just as the wasp impales its stinger in the door.

The Doctor and Agatha arrive, drawn up by the noise. Agatha dismisses the idea, thinking she was scared away by a normal, tiny insect, despite the giant stinger still embedded in the door. The wasp has fled by the time the Doctor makes his way into the room. He takes out a vial and pencil to collect a sample. He is suspicious, as while there are plenty of alien insects, none should be in this galactic vector. (Agatha understands some of the Doctor's words, but now thinks he's insane.) While Earth wasps are harmless without their stingers, this one is large enough that it will be able to regrow a new one. Agatha points out that there is no such thing as giant wasps. The Doctor agrees, so why is this one here?

In the kitchen, the servants speculate about the murder while cooking dinner, wondering who would want to kill Professor Peach. Mrs. Hart speculates that it's what happens when a party is thrown by the rich and famous. Miss Chandrakala dismisses the idea, telling them to get back to work. However, she then has an epiphany, realising exactly what Professor Peach had discovered in the library when he was murdered. She tells the staff that she must speak to Lady Eddison and rushes outside to find her. However, the wasp watches from above and knocks over a stone gargoyle from the ledge. It lands on Miss Chandrakala, crushing her to death. Hearing the thud and Miss Chandrakala's cry, the Doctor, Agatha, and Donna rush outside to find her slipping away. As she dies, Miss Chandrkala leaves them with a cryptic message: "The poor little child..." Seeing the wasp hovering over the ledge, the Doctor, Donna and Agatha give chase.

Donna notes how the roles are reversed this time as they're chasing the monster now. Agatha is still in denial about the wasp being real, thinking it's some kind of illusion done with mirrors. They find it breaking in through a skylight. The Doctor tries reasoning with it before they barely dodge an attack. Donna gets the wasp's attention and holds up the magnifying glass to threaten it with another shot of focused sunlight. It flies into the next hall as the Doctor yells for them to hurry, and not let it return to human form. Unfortunately, it manages to make it back to the guests rooms' and revert to human form, so when the Doctor shouts, "There's nowhere to run. Show yourself!" he is frustrated to only be greeted by confused reactions from all of the guests. He grumbles, "That's just cheating!"

Everyone gathers in the sitting room, where they pressure Agatha to solve the murders. However, she tells them that she is only a writer; the Doctor is their best chance at solving the case now. She retreats to the garden. Donna follows her to try to restore her confidence. Donna empathizes with the breakdown of Agatha's marriage, likening it to when Lance betrayed her to the Empress of the Racnoss. She also tries to lighten Agatha's spirits by positing her books will be turned into talking films, before realising her gaffe. Agatha, however, thinks that her books will fade out of interest over time, and she will be forgotten. Agatha then notices a case nearby that was tossed out one of the windows and has crushed one of the flowerbeds. Donna points out that nobody else would have noticed that.

They take it to the Doctor, in the sitting room. The case contains a thief's tools, and they suspect that the Unicorn is one of the guests. Greeves arrives with their drinks. Donna asks the Doctor what he found out about the venom from the stinger. Taking out the vial, the Doctor reveals that the venom comes from a Vespiform, a race of aliens who have hives in the Silfrax Galaxy. However, the question remains as to why it's on Earth and acting like a character out of one of Agatha's books. Donna then tries to invoke an idea by musing "what would Miss Marple do", pointing out the character's M.O., before again realising that she has given yet another idea to Agatha (for this, she decides to have Agatha copyright Miss Marple to both of them).

Suddenly, the Doctor begins convulsing in pain; someone has poisoned his drink. Agatha smells the drink, deducing from the telltale scent of bitter almonds that the poison is cyanide. The Doctor rushes to the kitchen, frantically asking for ginger beer (earning an irritated look from Davenport, the gay footman). Upon finding a bottle, he drinks some and then pours the rest on himself. Agatha insists that as an expert in poisons, cyanide is fatal, but the Doctor counters that as a Time Lord, he can stimulate the inhibited enzymes into reversal, thus curing himself. He next asks for protein and is given walnuts. Then he mimes a need for salt; when Donna tries to give him a bag of salt, he says pure salt is "too salty", so Agatha gives him a bottle of anchovies. Finally, he says he needs a big shock, in the form of a kiss from Donna. Cured, the Doctor exhales the poison in a cloud of smoke, saying he should detoxify more often. Agatha is flabbergasted, exclaiming, "Doctor, you are impossible! Who are you?"

By nightfall, a storm has brewed. As they are all seated in the dining room, the Doctor points out that they are still having dinner even though two people have died. Lady Eddison asks what he would want them to do; being British, they carry on. The Doctor then tells the guests that one of them failed to poison him. Any one of them could have put cyanide in his drink, so he's decided to test something by lacing everyone's soup with pepper. Colonel Hugh finds the extra spice delightful, but the Doctor explains that the active ingredient in pepper is piperine, traditionally used as an insecticide, with which he hopes to draw out the Vespiform.

At that moment, there is a flash of lightning and a thunderclap. A sudden gust of wind blows open the windows, and the candles go out. The Doctor asks the startled group to listen, and sure enough, the wasp's buzzing becomes audible again. Lady Eddison exclaims, "No... it can't be!" Agatha, meanwhile, stands up and calls "Show yourself, demon!" It does, above a painting, and the guests flee the dining room with Greeves pulling Donna to safety. The Doctor, Greeves, Donna and Agatha end up in the same room, just outside the dining room. The Doctor takes a sword from a nearby coat of arms and draws it. Donna half-jokes with Greeves beside her, "Well, we know the butler didn't do it." The Doctor asks in response, "Then who did?"

The Doctor rushes back in with the sword in hand and the others in tow, just as the lights come back on. The wasp is nowhere to be found. Lady Eddison, who was in her seat the whole time, then notices that her necklace, "the Firestone", has been stolen. Worse, the Vespiform has stabbed Roger in the back, and he has slumped face-forward into his soup. Lady Eddison goes over to her son, crying over his death.

Later, in the sitting room, the storm continues. Agatha is trying her best to cope with what's happened, with the Doctor at her side. Donna enters, feeling sorry for Davenport; he can't mourn Roger, because of the social mores of the 1920s. Agatha then asks Donna if she inquired about the Firestone. All Donna knows is that it's a priceless jewel that Lady Eddison brought back from India 40 years ago. The Doctor then begins wondering why the Vespiform hasn't used its abilities to kill them all already; instead, it's been playing this game. Agatha tells the Doctor to stop as she knows the murderer is as human as them. The Doctor then realises that Agatha is right, he's been so caught up in figuring out this giant wasp that he's forgotten that she's the expert. Agatha again refuses to believe her work is any good, dismissing herself as "just a purveyor of nonsense". The Doctor counters that the reason her books are so good is because she knows the human mind well. If anyone can solve the case, she is the one.

With her confidence restored, Agatha, the Doctor and Donna call the remaining four suspects together in the sitting room. The Doctor introduces Agatha, inviting her to begin. He takes a seat beside Donna. Between the two of them — the Doctor with his head rested on his hand and Donna munching a tray of grapes — they both look ready for something big to unfold. Agatha starts with Robina and quickly exposes her as an impostor, pointing out the thief's toolbox was found below her bathroom window. Agatha concludes Robina must have thrown them out when she heard Donna was searching the rooms. "Robina" is the Unicorn. Dropping her fake posh accent for an East-End one, the Unicorn confesses she stole and still has the Firestone, handing it over to the Doctor. She tells them that although she may be a thief, she's no killer. Agatha then turns her attention to Colonel Hugh. He confesses that he does not actually need his wheelchair. He's faked his disability in order to keep Lady Eddison at his side, fearing she would fall in love with another man, to which she is quite touched. When asked how Agatha figured out the truth, she tells him that she didn't. Much to his embarrassment, she was simply going to say he was innocent.

Agatha picks up the Firestone and says that it has quite the history... and is far more than the Unicorn's prize. She turns to Lady Eddison, who quickly pleads her innocence. Agatha asks Lady Eddison to tell them the story of bringing the jewel back from India, then suffering from malaria and keeping herself confined in her room for six months. Then, ignoring her pleas to stop, Agatha concludes that Lady Eddison actually came back from India pregnant. She concealed it with the aid of Miss Chandrakala, her Indian maid and confidante who would eventually become her housekeeper. Colonel Hugh asks his wife if it's true; she confesses it is, explaining she had no choice but to hide her pregnancy because of the scandal and shame it would bring to the family name to have a pregnancy out of wedlock. After all, "I'm British... I carry on."

The Doctor then takes control from Agatha momentarily, as they are now in his territory; he concludes that it was no ordinary pregnancy Lady Eddison experienced. The one thing about the dining room murder that has left him puzzled is her exclaiming "It can't be" at the sound of the Vespiform's buzzing, meaning she's encountered the Vespiform before and knows who it is. Lady Eddison tells the Doctor that he would never believe her if she told him. However, Agatha encourages Lady Eddison by explaining that the Doctor has opened her own mind into believing in the many possibilities the universe can hold.

Lady Eddison explains. In 1885, she was alone one night in Delhi when she saw a purple shooting star in the sky. The next day, she met a young man named Christopher, with whom she quickly fell in love and had an affair. Christopher revealed that he was a Vespiform who took human form to study Earth, but Lady Eddison loved him so much, she didn't care. Soon after, during the great monsoon when the Jamuna River broke its banks, he drowned. However, he left her both the Firestone and pregnant. Out of shame of the scandal that her out-of-wedlock baby would bring, Lady Eddison sadly gave up the child for adoption. Only Miss Chandrakala was trusted with the truth.

It is now that Donna realises that "maiden" on the paper meant "maiden name", which Agatha verifies as the reason Professor Peach was killed. He had found out who the child was and who the parents were, by discovering the birth certificate. Agatha then tells Lady Eddison that Miss Chandrakala had (correctly) feared that Professor Peach had found out the truth. She was coming to warn her. Just as Lady Eddison is about to break down, Agatha says that she is innocent of murder. She turns it back over to the Doctor.

He pops up as Agatha sits back down and starts, "Thank you! At this point, when we consider the lies and the secrets that are key to these events..." Firstly, the Doctor points at a confused Donna... to give her credit for her realization that everything in this case has been acted out like a murder mystery from one of Agatha's books. The Doctor dismisses the idea of Agatha being the killer, saying that she simply wrote those brilliant, clever books. The Doctor then points at Lady Eddison, who is an admirer of Agatha's works, and asks what she was doing the previous Thursday night. It turns out that Lady Eddison was reading her favourite Agatha Christie book, The Murder of Roger Ackroyd. She asks how it is relevant. The Doctor then points out that something else happened on Thursday night: Reverend Golightly subdued two thieves who broke into his church.

It is unlikely, the Doctor observes, that a meek man like Golightly could defeat two strong, younger men all by himself. It has also been forty years since Lady Eddison gave birth... and Golightly is 40 years old. Not only that, but he recalls Golightly's earlier statement in the afternoon where he said he was taught by the Christian Fathers, meaning that he was raised in an orphanage. Golightly is Lady Eddison's bastard son, and the night of the burglary, Golightly became deeply angry for the first time in his life. The genetic lock keeping him in human form was broken, and his alien biology was awakened. He transformed, frightening the thieves into submission. It also activated the Firestone, which is actually a Vespiform telepathic recorder, and part of Golightly's brain. When Golightly transformed for the first time, the Firestone also activated and beamed his full identity directly into his mind. Because Lady Eddison was both wearing the Firestone and reading Agatha's book at the time, her books' template for how the world should work was distorted into him.

Slightly miffed, Golightly says the evening has been entertaining and asks Lady Eddison if she believes what she's heard — but buzzes on saying her name. He does it again when the Doctor asks him to repeat himself, before warning the Doctor not to make him angry. Golightly sneers at the others, saying that humans worship tribal "sky gods" while he is so much more. After the upload of information from the Firestone, he wants to take what was his, inheriting the Eddison title. Blinded by rage, Golightly focuses on Agatha, asking why he shouldn't just kill everyone, as a pink light surrounds him. Eventually, he snaps and transforms into his wasp form. A frantic Lady Eddison reaches out as if to hug him, but is held back by the others as they retreat into a corner. At this, Agatha snatches the Firestone, screaming, "No! No more murder! If my imagination made you kill, then my imagination will find a way to stop you, foul creature!"

As she runs out of the room with Lady Eddison still screaming hysterically, Golightly pursues her and the Firestone, with the Doctor and Donna following them. Agatha takes a car and drives off, calling for Golightly to chase her, which he does. The Doctor and Donna follow the two of them in the late Professor Peach's car. The Doctor ominously warns that "time is in flux": History may change, and it may be that tonight could be the night that Agatha Christie loses her life instead. Agatha leads the creature to the Silent Pool lake. Stopping, she gets out and calls Golightly to her. As they arrive and hurry to her side, Donna realises that Agatha is controlling Golightly with the Firestone. The Doctor notes that Agatha is linked to his mind because his mind is based on her thought processes; if Agatha dies, then Golightly might die with her. The Doctor tries to persuade Golightly that he was not meant to be a killer, and has the wrong template in his mind.

Donna seizes the opportunity to snatch the Firestone from Agatha's grasp and hurl it into the water. Golightly shoots over their heads, splashes into the lake and drowns, just as his father did forty years before. A purplish light emanates from the spot where the Firestone and Golightly sank. Agatha gives a poetic speech as the purple light fades in the water. "Death Comes as the End, and justice is served." The Doctor decides to call this adventure Murder at the Vicar's Rage; at a look from Donna, he admits that the title needs some work.note  Agatha tells the Doctor there is just one more mystery left: his identity. However, she then cries out in pain and collapses. As the Doctor catches her, he realises that Golightly and Agatha are still linked. If Golightly dies, so does Agatha...

However, at the last second, before he passes into the next world, Golightly cuts the link. Agatha is bathed in the purple light for a few moments before she merely exhales deeply and faints. The Doctor remarks that it let her go... in the end, it chose to save her life. Donna then wonders what will happen now as the Doctor finally figures out how Agatha lost her memory: the psychic trauma of the link between her and Golightly being severed so violently. Donna is sad that this means she'll forget meeting them. The Doctor comments that they've solved their mystery and can now let — or help — history take its course. Keeping with the established timeline, the Doctor leaves Agatha's car by the lakeside, takes Agatha in the TARDIS and drops her off at the Harrogate Hotel ten days later.

As they watch a confused Agatha wander over to the hotel, Donna wonders about Lady Eddison, the Colonel and the servants, asking if they would tell anyone about what happened. The Doctor reminds her that they are far too British to tell such a shameful story and that the Unicorn will have escaped back to London. Donna then wonders what will become of Agatha; the Doctor explains that she will get married again (to Max Mallowan, with whom she'll stay with until her death), see the world and keep writing. Donna is sad to find that Agatha in the 1920s never thought her work was any good as they board the TARDIS...

...or maybe not. Back in the TARDIS, the Doctor speculates that Agatha never quite forgot what happened as he pulls open a hatch below the TARDIS floor. He pulls out a chest, where he stores souvenirs under the letter "C". Amongst the various knick-knacks he tosses out of it (including the globe imprisoning the Carrionites and a Cybus Cyberman chest emblem), is a copy of Death in the Clouds, an Agatha Christie novel from 1935 which features a gigantic wasp on the cover. Donna is shocked. The Doctor points out that as she had such a great mind, some of the details bled through — stuff her imagination could use, such as Donna's suggestions for Miss Marple and the basic plot for Murder on the Orient Express. However, the Doctor then has Donna look at the copyright page in front, which shows that the book is a reprint from the year five billion. Agatha Christie is quite literally the most popular writer of all time.

Donna then reminds the Doctor that Agatha never thought her work was good, but the Doctor responds, "Well, no one knows how they're going to be remembered. All we can do is hope for the best. Maybe that's what kept her writing. Same thing keeps me travelling. Onwards?"


  • Accent Relapse: After she's revealed a fraud The Unicorn drops her RP accent for a lower-class, vaguely Cockney one.
  • Actor Allusion:
    • David Tennant is from Scotland, and the national animal of Scotland is the unicorn.
    • Felicity Kendal (Lady Eddison) is best known for her role on Rosemary & Thyme, which is about two garden designers who solve crimes & mysteries at the same time, much like the story of this episode. And just like Lady Eddison, Kendal also spent some time in India, where she was brought up. As a result of this, she is fluent in Hindi.
    • Fenella Woolgar and David Tennant also acted together in BBC miniseries He Knew He Was Right.
  • Adaptation Dye-Job: Agatha Christie was actually a redhead in her younger days, not a blonde.
  • The Alcoholic: Lady Eddison spends a very good fraction of her screen time holding something alcoholic. Including that time she said it was tea.
  • The Alibi: As a homage to the tropes of Agatha Christie murder mysteries, the suspects in the murder of Professor Peach all have alibis. But when the Doctor questions each one of them, they only are being half-truthful about what they were actually doing at a quarter past four, and the one alibi flashback that matches up with the speaker's account is that of the actual perpetrator, Reverend Golightly.
  • All the Good Men Are Gay: After a somewhat overdone bit of Roger trying to flirt with Donna, only to then see some genuine flirting between him and Davenport.
    Donna: Typical. All the decent men are on the other bus.
    The Doctor: Or Time Lords.
  • Author Appeal: Gareth Roberts is a huge Agatha Christie fan and it shows.
  • Big Bad: Reverend Golighty.
  • Big Creepy-Crawlies: "When I say giant, I don't mean big, I mean FLIPPING ENORMOUS!"
  • Big Damn Kiss: The Doctor needs a shock. Donna's got a proper one for him. Notably, it's the only bit of intimacy that the two ever share, and it serves to prove that they really are just best mates.
  • Big Secret: Lots of them. Lady Eddison's Mysterious Past, Colonel Hugh's able-bodiedness, Robina Redmond's real identity, and Roger's relationship with the footman.
  • Bizarre Alien Biology:
    • The Doctor's ability to reverse cyanide poisoning using various substances. Whie some of the Technobabble he spouts is vaguely plausible, expelling the poison from his mouth as a gas rather stretches credibility.
    • Lady Eddison had a baby with an alien wasp.
  • Bitter Almonds: Dropped word-for-word by Agatha herself, followed by a Sparkling Cyanide reference.
  • Blatant Lies: Nearly all the suspects' statements about what they were doing when the murder took place are this, as flashbacks show they were actually having a gay tryst, looking at period porn, etc.
  • Brainwashed and Crazy: Poor Reverend Golightly. The Firestone his birth mother wears is meant to transmit information to him when he breaks the genetic lock of his human form and turns into a Vespiform for the first time in his life, to help him understand what's happening; unfortunately, she's reading an Agatha Christie novel when that happens, beaming murder-mysteries into his mind as the mental template instead and causing him to begin murdering people. (The famous plot twist of the novel in question probably did not help.) When the Doctor reveals this and tries to talk down Golightly, the man-Vespiform doesn't listen.
  • Bury Your Gays: Roger. Which, per the trope, would have almost made his sexuality usable in the story in the real 1920s since he was killed, appropriately enough by the Vicar.
  • The Butler Did It: Lampshaded but averted; "At least we know the butler didn't do it."
  • Cain and Abel: Lady Eddison's bastard son with a Vespiform, Reverend Golightly, kills his human younger half-brother as the final victim of the episode. Unlike Professor Peach and Miss Chandrakala, Roger had no idea of his brother's existence and wasn't threatening his secret, making it unclear if the reverend killed him out of jealousy, homophobia, or if Roger saw him change.
  • Call-Back: When Donna tries to blend in with socialite talk and by saying "topping day, what?", the Doctor tells her, "No-no-no-no, don't do that", like he did to Rose when telling her not to try doing a Scottish accent, and to Martha when telling her to stop using Ye Olde Butcherede Englishe. The very Edwardian Third Doctor greeted people with "topping day, what?" on occasion.
  • The Cameo: The Very Rev. Sandy McDonald, David Tennant's father, plays the footman at the beginning: he's the one in the foreground when Donna orders a sidecar. (A different footman from the one with whom Roger is in a relationship, by the way.)
  • Casting Gag: Fenella Woolgar, who plays Agatha Christie, also appeared in two of the TV adaptations of Agatha Christie's Hercule Poirot mysteries.
  • Changed My Jumper: Donna dresses in a period appropriate "flapper" outfit. The Doctor, as usual, just turns up in his brown suit.
  • Chekhov's Gun: The big, dorky magnifying glass is a pretty short-term one; after the Doctor gives it to Donna, she ends up using it about ten minutes later to hold off the giant wasp.
  • Classy Cat-Burglar: The Unicorn is capable of mostly-effortlessly posing as a posh woman, although she gets a lot less classy when she's exposed.
  • Cliché Storm: Donna Noble notices that the plot is being played out like a murder mystery story. It turns out the villain absorbed the works of Agatha Christie, which inspired him to kill the guests in the fashion of her books. invoked
  • Commonality Connection: During a scene where Agatha is mourning her failed marriage, Donna commiserates with her and mentions how her husband wasn't great either. After all, they were both betrayed by men that didn't see them as partners worth respecting.
  • Continuity Nod:
  • Conveniently Empty Roads: Justified. Agatha Christie starts a high-speed chase with a giant wasp pursuing her, and the Doctor and Donna following in another car. Since the chase happens along a rural country road, in the 1920s, at night, it's no surprise at all that they're the only ones in sight.
  • Daydream Believer: Donna really wanted to meet Noddy...
  • Death by Looking Up: Miss Chandrakala, in the courtyard, with the gargoyle.
  • Deliberate Values Dissonance: Donna calls attention to this by sympathizing with Davenport, who has just lost his boyfriend yet cannot even openly mourn because their relationship was illegal in that era.
  • Dramatic Irony: Donna finds the idea of Agatha Christie being involved in a real murder mystery as ridiculous as the idea of finding Charles Dickens surrounded by ghosts at Christmas. The Doctor looks embarrassed, given his personal experience.
  • Dying as Yourself: Hinted at for the reverend.
  • Earn Your Happy Ending: The Doctor assures Donna that, thanks to them leaving an amnesiac Agatha Christie at the hotel where she was found in the original timeline, she will recover from her trauma, marry a much better man, and become a successful author.
  • Elephant in the Living Room: Agatha's just learned of her husband's affair but doesn't want to admit to it (see Stiff Upper Lip). The Doctor reminds Donna of exactly why this was the case.
  • Exposition Beam: Lady Eddison's Firestone pendant triggered an invisible one that set off the real killer — her son.
  • Fake Food: The anchovies the Doctor eats were actually mushrooms.
  • Flashback... Back... Back...: The interrogated suspects have flashbacks (complete with wavy line dissolve) while establishing their alibis, revealing that all of them are lying. Then played with when Colonel Curbishley has a flashback within his first flashback. Then the Doctor has a flashback of his own when he recalls hunting in Belgium for Charlemagne, who'd been kidnapped by an insane computer...
  • Foreshadowing:
    • Golightly's interrogation flashback is the only one that matches up with his words, a clue in hindsight that he's the murderer.
    • Donna is upset that Agatha Christie would never know of the impact her writing would have for years to come, to which the Doctor replies "Well, no one knows how they're gonna be remembered. All we can do is hope for the best." Later on, Agatha gets Wistful Amnesia of the episode's events. Both of these become relevant to Donna's story in the season finale.
  • Genre Blindness:
    Professor Peach: I say... what are you doing with that lead piping?
  • Genre Savvy: The Doctor mentions that Donna was the first one to realize that the murders were playing out like those from Agatha's mysteries. Thus, he convinces Agatha to lend her mind to finding the real killer.
  • Genteel Interbellum Setting: A nice tea party in the Christie Time with Christie herself where being gay was illegal.
  • Giant Flyer: For once Donna, occasionally known to over-exaggerate, is not doing it. The wasp is ENORMOUS! It's an alien wasp after all.
  • Green Rocks: Well, purple — the alien jewel, the Firestone, that Christopher gave Lady Eddison is a Vespiform telepathic recorder. It beamed the Vicar's full identity into his brain when it was activated, and also beamed in the basic structure of an Agatha Christie novel, making him think the world actually worked that way, leading to the events of the episode.
  • Half-Human Hybrid: Half human and half giant space wasp.
  • Historical Domain Character: Agatha Christie.
  • Historical In-Joke: Christie's historic disappearance was due to a mystery-adventure with a giant space wasp. Who knew?
  • Impersonating an Officer: The Doctor passes himself off as an inspector from Scotland Yard so that no one will call the real police, especially because he's just noticed some morphic residue...
  • Improbable Antidote: Apparently, the Doctor can be cured of cyanide poisoning by drinking ginger beer, eating walnuts and anchovies and being kissed by a Fiery Redhead. (Technically, he asked for a shock, but Rule of Funny.)
  • Improvised Weapon: Donna uses a magnifying glass to burn the wasp.
  • Inflationary Dialogue: The Doctor gushing to Christie.
    "Oh, I love your stuff. What a mind! You fool me every time. Well, almost every time. Well, once or twice. Well, once. But it was a good once."
  • Inspiration Nod: The references to Cluedo (Clue for Americans) are clear. They make sure to work in Reverend Golightly (Reverend Green), Colonel Curbishly (Colonel Mustard) and Professor Peach (Plum). Similarly, Robina Redmond, Lady Eddison and Miss Chandrakala the housekeeper fit the typical characteristics of Miss Scarlet, Mrs. Peacock, and Mrs. White pretty well. They really hammer it home with the "Professor Peach in the Library with the Lead Piping" line, because that's how you might say it when you declare that you want to make an accusation.
  • Interrogation Montage: When the Doctor is questioning all the dinner guests about the murder of Professor Peach, he gathers them all together and then talks about the investigation.
  • Interspecies Romance: Lady Eddison and Christopher the Vespiform.
  • In the Past, Everyone Will Be Famous: Agatha Christie solving a murder mystery with the Doctor involving a giant alien wasp.
  • It's Always Spring: This episode is supposed to take place in December — which explains the lovely springlike weather present for the entire episode.
  • It Will Never Catch On: Agatha doubts Donna’s insistence that her work will have any staying power with the public, since they’re not “great literature” and will be forgotten.note 
  • I Want Grandkids: The Colonel comments that he and his wife are unlikely to have grandchildren, implying that he knows about Roger's sexual orientation.
  • I Will Show You X!: Donna will pluck you in a minute.
  • Karma Houdini: The Unicorn takes the opportunity to escape when the Vespiform attacks.
  • Kicking Ass in All Her Finery: Donna Noble fends off a giant wasp with her magnifying glass and helps chase down a killer, all while wearing her glittery "flapper" outfit.
  • Lame Pun Reaction: Donna gives the Doctor a disapproving look when he says "Murder at the vicar's rage."
  • Long-Lost Relative: Reverend Golightly turns out to be Lady Eddison's secret first son. She had given him up to avoid the scandal of her not being married to his father when she became pregnant.
  • Magic Pants: Apparently Vespiform can transform their clothes when they take on human form.
  • Meaningful Name:
    • Professor Peach, and possibly Miss Redmond, is a Cluedo (Clue for our American readers) reference. In fact, the Cluedo-ness of the situation is lampshaded by Donna.
      Donna: I mean... Professor Peach, in the library, with the lead piping?
    • The shapeshifting alien wasp is called a Vespiform. Which is Latin for guess what: wasp-shaped.
  • Mistaken Confession: As Agatha and the Doctor expose the house's secrets, the Colonel cracks and admits he doesn't need his wheelchair... much to their surprise.
    Agatha: Actually, I was going to say you're completely innocent. Sorry.
  • Mistaken for Romance: Agatha Christie briefly mistakes the Doctor and Donna for married before pointing out that neither is wearing a wedding ring.
  • Never One Murder: The story starts off with Professor Peach's murder, but then the killer strikes again before the mystery is solved.
  • Newspaper Dating: Played with. The Doctor uses sensory clues like Professor Peach's vintage car and the smells around him to determine that they are in the 1920s, then uses a newspaper to determine that they have landed on December 8, 1926. Subverted in that they are at a garden party on a sunny, warm, day with lush greenery all around. In England. In December.
  • Noodle Incident: The Doctor has been hunting in Belgium for Charlemagne, who'd been kidnapped by an insane computer.
  • NOT!: The Unicorn, in the more antiquated version.
    The Unicorn: Ever so nice to meet you, I don't fink.
  • The Noun and the Noun: The Unicorn and the Wasp.
  • Obfuscating Disability: A sympathetic take on it. Colonel Hugh pretends to be crippled, because he believes it's the only way a guy like him could keep his beautiful wife from leaving him for a more handsome man.
  • Oblivious Mockery: Donna's joke about meeting Charles Dickens "and he's surrounded by ghosts — at Christmas." The Doctor wisely doesn't admit he's done just that.
  • Oh, Crap!: The Doctor's reaction upon looking at a newspaper and realizing that today is the day Agatha Christie will disappear.
  • Ooh, Me Accent's Slipping: After the Mistaken Confession, Agatha, completely taken aback, slips from RP into Fenella Woolgar's Estuary English.
  • Overly-Long Gag: The far too long and extensive protestations of Roger's that he was alone.
  • Parlour Games: Charades, after the Doctor gets poisoned (and Donna is terrible at it — "How is Harvey Wallbanger one word?!").
  • Pass the Popcorn: Donna is doing this during the drawing-room reveal, with green grapes.
  • Plucky Girl: The Doctor invokes this with Donna by calling her "the plucky young girl who helps me out" to explain why she's going to investigate with him as policewomen didn't exist in the 1920s. Donna is offended.
  • Porn Stash: What the Colonel was really up to when the murder took place: looking at period porn.
  • Recycled IN SPACE!: An Agatha Christie mystery WITH AGATHA CHRISTIE! AND ALIENS!
  • Rewatch Bonus: When the Doctor is first questioning the suspects, the Reverend is shown to be the only one who is 100% telling the truth, when in fact he's the only one who is completely lying.
  • The Roaring '20s: The episode is set in 1926.
  • Rummage Fail: At the very end, the Doctor digs through some of his junk in the TARDIS (of the starts-with-a-C variety); before he finds his copy of Death in the Clouds, he pulls out the C logo off a Cyberman's chestplate, the head of a statue (Julius Caesar?), a crystal ball full of Carrionites (still screaming) and a big jumble of cables.
  • Running Gag: The one about the Doctor and Donna not being married and the one where the companion attempts an accent, and the Doctor tells her not to. Hilariously enough, the protestations turn out to be unnecessary; Christie noticed Donna didn't have a wedding ring.
    • This one is as much to draw attention to Christie's powers of observation as anything else. The 1920's Flapper was distinct from earlier generations of women in that she dated, and otherwise socialized with men absent of a chaperone. Unlike other historical periods where the Doctor has taken female companions, this was one where it was not Values Dissonance for him to be going around with a woman to whom he was not married.invoked
  • Samus Is a Girl: The mysterious jewel thief known as the Unicorn is referred to with male pronouns before Agatha correctly identifies The Flapper as her.
  • Shaped Like Itself:
    The Doctor: What do you mean, "a giant wasp"?
    Donna: I mean a wasp, that's GIANT!
  • Sherlock Scan: Agatha Christie works out that the Doctor and Donna aren't married before they tell her as neither of them are wearing wedding rings.
  • Shout-Out:
    • Rusty and Gareth Roberts had a bit of fun with the script. Gareth would pop a reference in, send the draft to Rusty, and it'd come back with another one, and so forth. All told, there are about 19 titles of Agatha Christie novels directly referenced in dialogue. Such as...
      • And Then There Were None
      • N or M?note 
      • Crooked Housenote 
      • Taken at the Floodnote 
      • Endless Nightnote 
      • Cat Among the Pigeonsnote 
      • Cards on the Tablenote 
      • Death Comes as the Endnote 
      • The Murder at the Vicaragenote 
      • They Do It with Mirrorsnote 
      • Murder on the Orient Expressnote 
      • Why Didn't They Ask Evans?note 
      • Nemesisnote 
      • Dead Man's Follynote 
      • Sparkling Cyanidenote 
      • Appointment with Deathnote 
      • The Secret Adversary
      • The Moving Fingernote 
      • They also have The Man in the Brown Suit (explicitly referred to as such in one of the bonus scenes on the series 4 DVD) solving the mystery of The Body in the Library. The reveal scene has the Doctor doing The Moving Finger.
      • The Doctor also has a copy of Death in the Clouds published in the year 5 billion and then some, no less.
      • The plot accidentally gets kicked off because Lady Eddison was reading The Murder of Roger Ackroyd.
      • When the identity of the Unicorn is revealed, the Unicorn's accent slips from upper class back to working class, which also happens when the jewel thief is exposed in the Poirot short story "The Veiled Lady".
    • And in a non-Christie Shout-Out, Colonel Curbishley's getting up from his wheelchair is from The Real Inspector Hound.
    • I'd like to make an accusation: it was Professor Peach in the library with the lead pipe. Lampshaded by Donna, even. (See Meaningful Name.)
  • Shown Their Work: Agatha Christie is depicted as owning a 1919-1926 Morris Cowley Bullnose. This was the very model car driven by the real Agatha Christie around the time of her disappearance in 1926.
  • Solar-Powered Magnifying Glass: Donna scares off the wasp the first time with a magnifying glass and sunlight.
  • Sssssnaketalk: In this case, "Wazzzzptalk". "Put thozzzzzze thingzzzzz back where you found them! It's-zzzzzzzzzZZZZZ!"
  • Stealth Pun:
    • At the end of the episode the Doctor pulls things filed under "C" from (what else?) a sea-chest.
    • The wasp is a WASP.
  • Stiff Upper Lip:
    • The Doctor on Agatha's Stepford Smiler habits while mingling with the party guests.
      Donna Noble: You'd never think to look at her. Smiling away.
      The Doctor: Well, she's British and moneyed. That's what they do; they [posh accent] carry on. Except for this one time.
    • The Doctor, later, as the party guests sit down to dinner:
      The Doctor: A terrible day for all of us. The professor struck down, Miss Chandrakala cruelly taken from us. And yet we still take dinner.
      Lady Eddison: We are British, Doctor. What else must we do?
  • Stigmatic Pregnancy Euphemism: In this case, she had "malaria" because "pregnant with a half-wasp-alien child" just isn't proper.
  • Summation Gathering: With Donna enjoying the show and repeatedly accusing the wrong people.
  • Super Drowning Skills: Vespiform are helpless against the might of a calm and peaceful lake.
  • Suspiciously Specific Denial: "Oh, yes, all alone. Totally alone. Absolutely alone. Completely. All of the time. I wandered, lonely as the proverbial cloud. There was no-one else with me; not at all! Not ever!" (flashback shows him flirting and holding hands with his footman)
  • That Came Out Wrong: After the Doctor gets snogged by Donna and subsequently "detoxes"...
    The Doctor: Detox! Mwa! Oh, I must do that more often!
    Donna: ...
    The Doctor: I mean, the... the detox.
  • The Theme Park Version: The writer deliberately went for the popular perception of a Christie novel as opposed to what they're actually like.
  • Title Drop:
    Agatha Christie: The Unicorn. He's here!
    The Doctor: The Unicorn and the Wasp...
  • Troperrific: The Doctor clearly knows and is loving every moment of it.
  • Unreliable Voiceover: Most of the "Where were you at a quarter past four?" flashbacks when the Doctor is asking the suspects do not come close to what the character says they were doing, with funny actual stories:
    • Reverend Golightly says he was unpacking in his room. His is the only one where the narration and the flashback match up. Which is a clue that he's the actual culprit.
    • Roger says he was going out for a stroll by himself behind the house. He was out for a stroll, yes, but he was actually meeting for a little tryst with Davenport.
    • Robina Redmond says she went to the toilet. This one is partially true: what she isn't mentioning in the narration is that the flashback shows her checking a tiny pistol.
    • Colonel Hugh says he was in the study remembering memoirs. What he was actually looking at were erotic photos, which causes him to slip into a second flashback with some can-can dancers. The Doctor has to snap him out of each layer of flashback separately.
    • Lady Eddison says she was drinking her afternoon tea. She was actually drinking some spirits from a flask.
  • Unstoppable Rage: Murder at the Vicar's Rage (*ahem*) ensues when the boys are stealing things from the church.
  • Vertigo Effect: On Lady Eddison, when she realizes that the reverend is the child she gave up forty years ago.
  • The Vicar: Turns out he is the murderer.
  • Victoria's Secret Compartment: The Unicorn, upon being exposed as both being present and having stolen the Firestone earlier, pulls the gemstone in question out of her décolletage.
  • Villain's Dying Grace: When he and Agatha are telepathically linked as he is drowning, Reverend Golightly ultimately spares Agatha's life as his final act by releasing her from the link before she can also die. Especially noteworthy as the Doctor was not even present to talk him into it.
  • What the Hell, Hero?:
    • Agatha makes it clear she doesn't approve of the Doctor having fun during the investigation.
    • The Doctor isn't too pleased when Donna drowns the Vespiform by tossing the Firestone into the lake.
      The Doctor: Donna, that thing couldn't help itself.
      Donna: And neither could I!
  • Who Are You?/What the Hell Are You?: Agatha's understandable reaction to the Doctor exhaling deadly poison as a cloud of black smoke.
  • Whole-Plot Reference: Gareth Roberts based the episode on his favourite Christie works: Crooked House, which focuses on secrets within an aristocratic society, and the 1982 film adaptation of Evil Under the Sun.
  • Why Don't You Just Shoot Him?: Defied by Donna; she knows that the Vespiform is beyond reasoning and will kill Agatha if she and the Doctor try to talk Golightly down. She grabs the Firestone and tosses it in the lake, to draw the line of fire from Agatha and drown the wasp.
  • Wicked Wasps: The Monster of the Week is a Vespiform: a giant, blasphemous wasp driven to commit murder.

Alternative Title(s): Doctor Who NSS 4 E 7 The Unicorn And The Wasp