On the HSS Matilda, a Generation Ship carrying the remnants of humanity to The Promised Land, technology has disintegrated almost to pre-industrial levels. The decks are arranged according to a strict caste system similar to Antebellum America. Inhabitants of the higher decks live on lavish estates, while on the lower decks, known as the Tarlands, dark-skinned workers suffer horrible abuse and privation.
Aster Grey is a doctor from Deck Q. Her expertise and skill, as well as her friendship with the ship's Surgeon General Theophilus Smith, give her far more freedom and social status than most of her fellow Tarlanders. When the Sovereign is poisoned, Aster tries to find out how, in the process unraveling a mystery involving the ship's life-threatening blackouts and the journals of her mother Lune Grey, who cut her own throat the day Aster was born.
An Unkindness of Ghosts contains examples of:
- Abandoned Area: Aster has turned a mess hall on Deck X, which was abandoned after a massive flood, into her own illicit botanarium to grow medicinal plants, store her secret research notes, and get some privacy.
- Air-Vent Passageway: Aster and Giselle run into the boiler room, climb up the pipes, and flee into the air duct to escape guards.
- Ambiguous Gender Identity: Theo's gender identity is ambiguous even to him, since his rigid, dogmatic society doesn't acknowledge transgender identities. However, he deliberately avoids some elements of masculine gender expression, secretly takes testosterone blockers, and outright tells Aster that he's not a man.
- Apocalypse How: Class 3, cause unknown. There are no humans left on Earth, but plant life and at least some animal life has survived.
- Bastard Angst: Theo is the product of an affair with a black woman, and the resulting scandal forced his father's resignation as sovereign. His father deeply resented him as a result.
- Bittersweet Ending: Bordering on a Downer Ending. Aster makes it alive to Earth, where plant and animal life have fully returned. But the only people she brings with her are two dead bodies, so she has no chance of rebuilding humanity. Back on Matilda, a Slave Revolt kills hundreds, and we never find out if life actually improved for the Tarlanders or not, nor if Theo, Melusine, or the other protagonists survived.
- Blanket Fort: Aster and Giselle hide inside one while they work on decrypting Lune Grey's notes.
- Bungled Suicide: Giselle attempts suicide by burning down Aster's arboretum with herself inside. She is rescued by Theo, who thought she was Aster. If he'd known who she was, he would have let her die quickly, knowing she was scheduled for a Public Execution.
- Character Tics: Aster bangs against things as she moves to synchronize herself with the ship's rhythms, which calms her.
- Child Prodigy: At age twelve, Theo reinvented the polio vaccine, becoming ill himself and losing part of his leg. At age thirteen, he invented a better artificial heart than the one that already existed, saving Sovereign Nicolaeus's life.
- Condescending Compassion: Lieutenant pities the lower-deckers for their "ugliness" and supposed moral inferiority, saying, "We try to tame you, but there is no taming vermin."
- Dead Person Impersonation: After Cassidy Ludnecki died, his brother Seamus offered his identity to a white-passing lowerdeck man who wanted to attend medical school.
- Death by Childbirth: Giselle was raised by Melusine because her mother died giving birth to her younger sibling, Emile.
- Devil Complex: Giselle publicly declares herself to be the Devil at her execution. Given her mental state, it's unclear how literally she means it, but she's immediately taken up as an Icon of Rebellion against the Sovereign's despotic regime.
- Due to the Dead: After Giselle's death, bystanders gather around and cover her with jackets. They carry her away on a stretcher to the Shuttle Bay, from which Aster takes her to Earth and gives her a proper burial.
- Dystopia Justifies the Means: Lieutenant is an Egocentrically Religious ruler whose increasingly brutal and arbitrary persecution of the lowdeckers is revealed to be motivated by racial hatred against them.
- Expecting Someone Taller: Theo shows his ID card to a man at Lieutenant's coronation. The man says, "You-you're the Surgeon? I imagined you to be - grander," and looks Theo up and down.
- Eye Scream: Theo shoots a tranquilizer dart right into Lieutenant's eye, killing him.
- Finally Found the Body: Everyone assumed Lune Grey crawled into some hiding spot where no one would find her and killed herself. In fact, she was poisoned by siluminium while repairing a dent in the hull, a task she knew would be fatal, so that others would have a chance of reaching Earth. Aster finds her skeleton in the shuttle twenty-five years later.
- Forced to Watch: Lowdeckers are gathered from all around to watch Giselle's public execution in the Maple Wood, their place of worship, in order to Make an Example of Them.
- The Illegible: Aster's notes look like they were written by a two-year-old. Giselle is the only person who can read them, including Aster herself.Theo: What language are you writing in?
Aster: Q.note
Theo: You invented a personal alphabet then?
Aster: It's the standard alphabet. - Intersex Tribulations: Thanks to a variety of hormonal disurbances, Tarlanders are very likely to have intersex conditions, hence Aster's hairiness and muscular build despite her lack of external testicles. One theory among people from the higher decks is that the Tarlanders are descended from the World of Chaos, and when the Heavens overruled their world, their demonic bodies could not conform to the Holy Order. This is used as an excuse to dehumanize the Tarlanders even more.
- Kick Them While They Are Down: Aint Melusine always taught Aster that this is the best time to attack someone. When a middecker tells her she's not supposed to do that, she's surprised, as she's never heard of such a rule.
- Literal-Minded: Aster. When Theo asks, "What have I done but keep you safe?" she says, bewildered, "Do the meals you take keep me safe? Your baths? The books you read? I'm sorry, I'm afraid I don't understand."
- Mammy: Upperdecker women hire Melusine to nanny and tutor their children in preference to a "proper" tutor, solely because she fits the stereotype. She puts on a convincing façade but dislikes the work, even though it's less physically demanding than her main job.For some reason, people think I'm a motherly type. Because I'm brown and dowdy.
- Meaningful Rename: Theo's birth name is Sedvar, meaning merciless in battle, after his father. At age eight, he informed his father that from now on he would only answer to Theo. His stated reason is that Theo Thackeray was the protagonist of stories his nanny Melusine would tell him, but Aster suspects his real reason is to express his obsessive devotion to God.
- Nice Job Breaking It, Hero: In the first chapter, Aster amputates part of the foot of a child who developed frostbite and then gangrene as a result of the blackouts imposed by the government. Aster keeps the foot, and later leaves it as a present for the new Sovereign to show him that the blackouts have consequences. The child is publicly executed for Aster's crime.
- Parental Substitute: Aster's Aint Melusine, who raised her from age three after her birth mother's suicide, along with Giselle Nwaku. Melusine privately considers herself Maternally Challenged, but they love each other like a family all the same.
- Perma-Stubble: Nearly every upper-deck man who doesn't have a full beard keeps his face stubbled. Theo's clean-shavenness makes him a rare violator of the norm.
- Playing House: One of Aster and Giselle's childhood pastimes. Aster would play the domineering husband, repeating lines she'd heard while working on the upperdecks, and Giselle would play the angry wife.Aster: Wife, I require supper. I am hungry, as the mental effort required to digest politics is quite taxing. You would not understand.
Giselle: Cook your own goddamn supper, fool, if you're so hungry. Why don't you ask that slut secretary of yours to make you supper? Huh? Huh? You saw her again, didn't you? - Posthumous Character: Aster spends much time poring over the notes left by Lune Grey, especially after Giselle realizes they're in code.
- Pre-Climax Climax: Aster and Theo.
- Prefers Proper Names: Theo has called people by their proper names all his life, even addressing his father by his rank and surname. It's a sign of both his sense of propriety and a deeply isolated and emotionally abusive childhood. He keeps the habit with the few people he does care about, which Melusine privately admits causes her a bit of a pang.
- Punishment Box: Aster is put in the brigbox, a cell too tiny to stand up or lie down, just sit with her knees curled to her chest.
- Rape as Drama: Rape of Tarlanders by guards is so rampant that Aster smears a numbing, lubricating cream in her genitals every morning, just in case.
- Reverse Arm-Fold: Aster does this when she talks to people who have authority over her, in order to stop herself from fidgeting or doing anything that might be seen as disrespectful.
- Robbing the Dead: Aster steals the clothes of a guard she kills in self-defense.
- Secret Underground Passage: Sovereign Nicolaeus has a secret trapdoor under a chest in his chambers that leads to a Secret Room that contains one of the very few windows in the entire ship.
- Self-Harm:
- Giselle is obsessed with fire and doesn't mind burning herself. The way she sees it, everything will be destroyed eventually, including her body, so she might as well burn her hands now when she can control it.
- Theo self-flagellates and sleeps in a salt bath to rid himself of his impure thoughts about Aster.
- Single Phlebotinum Limit: The knowledge has been lost, but the Generation Ship relies on siluminium to distort space and travel at relativistic speeds. The metal is liquid at room temperature and somehow lighter than water, and its anomalous properties are responsible for both a mysterious poisoning incident and several blackouts when the ship is secretly rerouted.
- Sleepy Depressive: Giselle spends some time not wanting to do anything but lie in bed. Aster does this too for a few days after Flick's execution.
- Snake Oil Salesman: Jane, the "queen of snake oil," sells all manner of sketchy serums that rarely do what they're supposed to and often have horrifying side effects.Haneefa: That greedy cow would sell a ball of lint and call it a cure for cancer. For all you know, you swallowed a vial of arsenic.
- Spark of the Rebellion: Aster runs to Giselle's body after her death and is brutally beaten for it by a guard. Theo orders the guard to stop, in defiance of Lieutenant's orders, then shoots him with a fatal overdose of the poison he planned to use to fake Giselle's death. When Lieutenant tries to have Theo taken away, Aster charges a guard, and Theo shoots Lieutenant. This kicks off a riot, which turns into a shipwide mutiny that kills hundreds.
- Sweet Polly Oliver: Theo disguises Aster as a boy named Aston to sneak her into Lieutenant's coronation.
- Success Through Insanity: Giselle sees the world in a vastly different way to most, and thus is the first to notice that Lune's seemingly mundane notes were actually code for a world-changing secret.
- A Taste of the Lash: A common punishment for Tarlanders who commit any transgresions.
- Time Dilation: While 325 years passed on Matilda, more than a thousand have passed on Earth, which Aster hopes is now able to support human life again. When she arrives on Earth, all evidence of the unnamed ecological catastrophe has indeed disappeared.
- Toxic Friend Influence: Lieutenant, Theo's uncle, tells him that his friendship with Aster is bad for him, and he shouldn't pay attention to "her ilk." Theo is pretty sure Lieutenant just wants as much control over him as possible.
- Trauma-Induced Amnesia: Theo can't remember most of his childhood, which Aster thinks is due to his father's abuse.
- Unspecified Apocalypse: We never learn how humanity went extinct on Earth.
- Use Your Head: Before she can be hanged, Giselle turns and headbutts her guard in the nose, startling him into dropping her. This allows time for Aster to toss her a knife, which she uses to kill herself.
- We Need a Distraction: Aster first met Theo when she was fifteen, when he performed an illicit abortion on Giselle. On the way home, she heard guards coming and smashed a temperature gauge to allow Giselle and Melusine to escape. Theo protected her from harsh punishment and took her on as his assistant, as she had displayed some impressive medical aptitude during the abortion.
- Why Couldn't You Be Different?: As if his scandalous birth wasn't bad enough, Theo was a sickly and girlish child, not the strapping lad his father hoped for. His father would violently beat him for anything remotely feminine.
