All of Us Murderers

The novel follows Zebedee "Zeb" Wyckham, a chronically disorganized man who fidgets constantly and plays with rosary beads to manage his restless energy. Recently sacked from his job, Zeb accepts an invitation to spend a fortnight at Lackaday House, a remote Gothic mansion on Dartmoor owned by his cousin Wynn Wyckham. The estate is surrounded by a twelve-foot spiked wall with locked iron gates, and Zeb's unease grows when the contemptuous chauffeur deposits him at the front door without a word.

A barefoot young woman in a white nightgown runs past him, sobbing, into the dark gardens. The tall man in the doorway dismisses her distress, and Zeb recognizes him with a shock: Gideon Grey, his ex-lover, now serving as Wynn's confidential secretary. Gideon is coldly formal, explaining that the fleeing woman is Jessamine Wyckham, a cousin Zeb never knew existed. The other guests are equally unwelcome: Zeb's estranged older brother Bram Wyckham, a pompous literary critic; Bram's wife Elise; their dissolute painter cousin Hawley Wyckham; and Colonel Wyckham Dash, a second cousin.

At dinner, Wynn reveals that Jessamine is the granddaughter of Laura, a daughter of their grandfather Walter Wyckham, a popular Gothic novelist and former slave trader. Though technically Wynn's aunt by birth, Laura was raised alongside him as a sister. Laura became pregnant at sixteen and was sent away; her daughter Georgina was later seduced, bore Jessamine, and died by suicide. Wynn has raised Jessamine in seclusion and now announces he will leave his entire fortune to whichever man marries her, overturning Bram's long-held expectation of inheriting and sparking a bitter argument.

Zeb refuses to marry Jessamine and wants to leave. Wynn reveals he is terminally ill, connecting his impending death to a "Wyckham curse": a supposed deal Walter made with the devil that allowed him to live past fifty at the cost of every subsequent family member dying young. Wynn begs Zeb to stay, and Zeb reluctantly agrees, promising to keep the illness secret. Gideon confronts Zeb at the stone circle, one of several Gothic follies Walter built on the grounds. He accuses Zeb of pursuing the inheritance and warns he cannot afford to lose another job, having been unemployed for nearly a year after being sacked from Cubitt's, their former workplace, because of Zeb. Hawley also corners Zeb, threatening to expose him as a homosexual if he does not withdraw.

Strange events intensify. Going to bed, Zeb encounters a grey, cowled figure with a featureless face that vanishes when he gives chase. Jessamine insists the ghost is real and connected to a medieval monastery once on the site; Zeb recognizes it as identical to the ghost in Walter's novel The Monastery. At the stone circle, Zeb reveals to Gideon the true reason he does not want the inheritance: a man named Jerome, a descendant of people Walter enslaved on his plantations, told Zeb the family fortune was built on slavery. Zeb refuses to profit from it. Gideon is moved, admitting he believed Wynn's false claims that Zeb came for the money.

At a catastrophic dinner, Wynn publicly disinherits Bram and pressures Zeb to propose to Jessamine. Zeb refuses. Colonel Dash offers Jessamine his hand instead. That night, Zeb returns to his room to find it infested with hundreds of spiders, a targeted attack on his severe phobia, and the word "Sodomite" scrawled on removable wallpaper. He flees to Gideon, who concludes the terror is an organized campaign orchestrated by Wynn using his staff, since the hauntings predate the family's arrival. During their first reconnection since the breakup, Gideon reveals that Wynn hired him specifically because he knew about their failed relationship, and that Wynn has been systematically lying to everyone and stoking rivalries.

Elise privately tells Zeb she believes Jessamine is a fraud, an actress planted by Wynn. She suspects Wynn may not be dying at all and seems willing to leave with Zeb. That evening, a scream echoes through the hall. Elise lies dead at the bottom of the stone staircase, her neck broken. Gideon saw someone moving from the top of the stairs.

Wynn sends the motor for police, but the chauffeur returns alone, claiming fog forced him back. The gate is locked. While Zeb is occupied with Elise's funeral procession to the family crypt, Gideon's attempt to bribe the chauffeur is caught, and Wynn threatens his career. The next morning, thick mist traps everyone at the estate.

During this enforced confinement, Zeb and Gideon discuss their breakup honestly. Gideon had asked for a lifelong commitment; Zeb, terrified of promises after a lifetime of being punished for breaking them, responded devastatingly: "I dare say I could give you the evening." His fear stems from his upbringing, where his father demanded impossible promises, and then Bram swore at their father's deathbed to care for Zeb only to cut him off financially. Both acknowledge their shared fault. Zeb also reveals he is the bestselling children's author Zinnia Waters, creator of the Faraway Meadow series. They agree to start again through daily renewal rather than grand pledges.

Zeb makes alarming discoveries. Dash has vanished, his evening clothes missing. The altar stone is drenched in fresh blood. In the tower, Zeb finds a locked room with every surface covered in desperate writing: "LET ME OUT," repeated endlessly. This was where Wynn's father imprisoned Laura's mother for seven years until she died by suicide. In the library, Zeb finds a paper in Wynn's handwriting listing every Wyckham relative's age at death, calculating how many years Walter "gained" from each premature death. On the reverse, Wynn has listed the current guests and concluded he could live to sixty-one if they all died now. Zeb realizes Wynn intends to replicate Walter's supposed satanic bargain, and that the entire visit has been staged as a recreation of Walter's Gothic novels.

Gideon is beaten and captured by Wynn's staff. Rachel, the housemaid, helps Zeb free him and reveals that every staff member was personally wronged by a Wyckham. Rachel herself was raped by Hawley; the chauffeur's daughter was Bram's pregnant mistress, who died from a botched abortion after being abandoned. Colonel Dash, Rachel reveals, was the man who impregnated the teenage Georgina, making him Jessamine's father. When Zeb asks what happened to Dash, Rachel refuses to answer. She agrees to signal when the grocer's cart arrives so they can escape and shows them a secret passage leading outside.

When Rachel's signal sounds, Zeb is trying to warn Bram, who is in a dissociated state from Wynn's drugged cigarettes and confesses to pushing Elise down the stairs. Wynn arrives with Jessamine and, accusing Zeb of plotting to murder Bram, locks him in the library. Gideon, who refused to leave without Zeb, navigates the secret passages and opens a hidden panel from the other side. They escape through cobweb-filled corridors and emerge outside.

They spot the grocer's cart heading for the gate. Despite Gideon's injured ribs and Zeb's exhaustion, they sprint after it, catch it, and persuade the driver to take them to town. Lying flat in the cart, they pass through the iron gates as they screech shut. Gideon whispers, "Still us," and Zeb squeezes his hand.

In the epilogue, the coroner's inquest accepts Wynn's account: Bram killed Elise, Hawley shot Bram, and Hawley jumped from the roof. Zeb's testimony is dismissed. Months later, on the eve of Wynn's fiftieth birthday, the house's gas plant explodes and Lackaday House burns. Wynn dies in the fire, and a decayed body identified as Dash is found in a disused well. The body of the woman who posed as Jessamine Wyckham, revealed as one Jessamine Evans, is never recovered; a woman matching her description boards a transatlantic steamer carrying nearly fifteen thousand pounds and disappears. Zeb inherits the remaining fortune and places it into a trust for repatriation to the islands where Walter's plantations operated, administered by Gideon, his live-in partner. Zeb goes on to a forty-year career as a beloved children's author.