Nathaniel's parents announce they are leaving for Singapore, placing the siblings in the care of their lodger Walter, nicknamed The Moth.

Nathaniel and Rachel persuade The Moth to withdraw them from boarding school and allow them to live at home.

The siblings meet Norman Marshall, known as the Pimlico Darter, a former boxer and greyhound smuggler who frequents their home.

Rachel discovers Rose's packed trunk in the basement, revealing their mother never boarded a ship to Singapore.

Nathaniel begins working at the Criterion Restaurant under The Moth's employment, operating the manual lift and washing dishes.

Nathaniel starts joining The Darter on a mussel boat at night to smuggle race dogs along the Thames.

Nathaniel is attacked by two strangers in a subway elevator and escapes by releasing the lift's brakes.

Armed men attack The Moth, Nathaniel, and Rachel, triggering a rescue operation by Arthur McCash and The Darter's team.

The Moth is killed during the armed attack while protecting the children from abduction.

Nathaniel briefly reunites with Rose inside a theater after the attack; she tells him she accepted a mission to keep them safe.

Rachel and Nathaniel are separated and swiftly sent to different boarding schools far from London.

Rose returns from her mission and settles in White Paint, her childhood home in the Saints in Suffolk.

Rose is shot dead through her greenhouse window by an assassin while Nathaniel is away at university.

Nathaniel takes a job censoring wartime records at the Foreign Office archives, secretly intending to research his mother's identity.

Nathaniel visits The Darter and later deduces that Agnes became The Darter's wife and their daughter is likely Nathaniel's own child.

When Nathaniel and Rachel Williams's parents depart for a supposed work assignment, the siblings are placed in the care of their mother's enigmatic colleague Walter, known as The Moth, surrounded by a cast of shadowy figures in postwar London. They slowly adapt to a strange new life while their mother's absence deepens into a disturbing mystery, and a series of dangerous encounters culminates in a violent attack that kills The Moth and briefly reunites the children with Rose before they are sent to separate schools. Years later, Nathaniel learns that Rose led a double life as a wartime intelligence agent and was ultimately assassinated in her greenhouse by someone her work had wronged. As an adult, Nathaniel takes a job in the government archives to uncover his mother's secrets and piece together the truth of his fractured upbringing. The story closes when Nathaniel visits his old guardian The Darter and realizes his own acts of abandonment mirror his mother's, leaving him to confront the unresolved damage of a childhood shaped by war and deception.

Two abandoned siblings and their mother's deadly secret life

The Moth invites a cast of eccentric associates into the siblings' home, including beekeeper Mr. Florence and ethnographer Olive Lawrence.

The Moth reveals Nathaniel's repressed childhood memory of his father killing a pet cat, which Nathaniel had entirely forgotten.

Nathaniel works in the laundry room and operates the Criterion's manual lift, befriending the boisterous storyteller Harry Nkoma.

The Darter calmly helps Rachel recover from an epileptic seizure and teaches Nathaniel how to assist her in the future.

Olive Lawrence takes Nathaniel and Rachel on a nighttime walk and teaches them to identify the subtle sounds of nature.

Nathaniel begins dating a co-worker who calls herself Agnes Street, and the two sneak into vacant real estate listings together.

Nathaniel and Agnes become lovers, spending evenings in empty dark flats and eating food stolen from the restaurant.

Nathaniel and Agnes are followed by a stranger on a bus ride but manage to evade him.

Nathaniel introduces The Darter to Agnes as his father, and Agnes begins joining them on the barge journeys along the Thames.

Arthur McCash questions Nathaniel about the elevator attackers and assures him that his mother is alive and safe.

During university holidays, Nathaniel lives with Rose at White Paint and works for neighbor Sam Malakite in his vegetable fields.

Nathaniel and Rose argue about Rachel's estrangement, and Rose explains that the sound of wartime bombers compelled her to join the war effort.

Sam Malakite finds Rose's body in the greenhouse and calls the emergency number she had prepared for exactly this scenario.

Nathaniel returns to the Saints for Rose's funeral and finds the evidence of her murder has been completely scrubbed away.

Nathaniel moves permanently to the Saints, purchases the Malakites' home, and spends his evenings alone in the walled garden with a pet greyhound.

Amid the uncertainty of his parents' absence, Nathaniel finds unexpected belonging through the eccentric associates The Moth brings into the household, including the worldly ethnographer Olive Lawrence and the warm storyteller Harry Nkoma at the Criterion. His first romance with Agnes Street introduces him to love, class, and the liberating thrill of secret lives, while his nighttime work on The Darter's mussel boat gives him independence and a surrogate family. A series of encounters with Arthur McCash and the growing threat of unknown pursuers gradually transforms Nathaniel's adventure-filled adolescence into something genuinely dangerous. Later, his fragile time with Rose in Suffolk is shaped by arguments, silences, and the steadying friendship of neighbor Sam Malakite, who becomes one of the most reliable figures in Nathaniel's life. Rose's death leaves a chain of unanswered questions that no archive can fully resolve, and Nathaniel's slow investigation through records and rural Suffolk yields only fragments. The story ends with Nathaniel settling into the Malakites' home in an isolated, contemplative life, surrounded by the incomplete stories of those who once surrounded him.

The relationships and quiet moments that shaped Nathaniel's coming-of-age

The Moth confesses he has lost all contact with Rose and cannot tell the siblings where she is.

Nathaniel and Rachel secretly follow their mother through the city and are shocked to see her enter Wormwood Scrubs prison.

Nathaniel burns his school report card to conceal his failing grades and truancy from The Moth.

Nathaniel glimpses what he believes is his mother watching him from across a crowded dance club.

Arthur McCash calls out Rose's pet name for Rachel, Wren, inside the theater to prove he can be trusted.

Rachel refuses to leave The Darter's side after the attack and openly blames Rose for The Moth's death.

As adults, Rachel introduces Nathaniel to her infant son, whom she has named Walter after The Moth.

After Rose's funeral, Nathaniel finds a hand-drawn map hidden inside a Balzac novel on his mother's bookshelf.

Nathaniel recognizes that Marsh Felon, the man who tried to speak to him at the funeral, is the boy from Rose's childhood stories.

Nathaniel breaks into restricted archive cabinets and discovers Rose operated as a high-level agent under the codename Viola.

Archival records reveal that Rose intercepted coded German radio signals from a hotel rooftop and transmitted them to Bletchley Park.

Nathaniel translates an audio recording of a woman interrogating a man later identified as Marsh Felon, who is searching for Viola.

During the recorded interrogation, Felon inadvertently reveals Rose's identifying birthmarks, exposing her location to her pursuers.

Nathaniel discovers that Rose's intelligence work in Italy provided information to Yugoslav Partisans who carried out mass killings in the foibe massacres.

Nathaniel notices framed embroidery about wishing for a large pearl on The Darter's wall and realizes that Sophie, The Darter's wife, is Agnes.

The turning points in Nathaniel's story begin with the slow unraveling of his mother's cover, from The Moth's admission that Rose never reached Singapore to the siblings secretly tailing her to Wormwood Scrubs prison. Small moments of exposure accumulate until the violent attack forces everything into the open, splitting the siblings apart and leaving Rachel permanently estranged from her mother and aligned with The Darter. As an adult working in the archives, Nathaniel methodically uncovers the layers of Rose's identity, learning she was a high-level signals intelligence agent codenamed Viola whose wartime decisions in Italy contributed to mass killings. A translated interrogation recording of Marsh Felon becomes the key that unlocks the chain of events leading to Rose's murder, revealing how her own mentor inadvertently betrayed her by disclosing identifying details. Even after the archival trail goes cold, personal revelations keep arriving — Rachel honoring The Moth through her son's name, and Nathaniel realizing with sudden clarity that Agnes was The Darter's wife all along. Each discovery reframes the past without resolving it, leaving Nathaniel with a fuller but still incomplete picture of the people who shaped and damaged him.