Abigail Rook arrives in New Fiddleham from England, seeking employment and adventure on her own terms.

Jackaby hires Abigail as his investigative assistant after she proves her observational skills at a crime scene.

Jackaby and Abigail examine journalist Arthur Bragg's murder scene and discover that much of the victim's blood is mysteriously missing.

Jackaby loans a supernatural tuning fork to neighbor Mr. Henderson, whose apartment is close to the murder scene.

Jackaby identifies the silently screaming Mrs. Morrigan as a banshee predicting the imminent death of Henderson.

Jackaby secretly re-enters Bragg's apartment and steals a map marked with multiple locations across surrounding areas.

Hatun tells Jackaby she witnessed the killer climbing out of the murder building while wearing metal shoes.

Jackaby receives telegrams confirming that the stolen map tracked a string of murders in nearby cities.

Charlie Cane arrives to report that Henderson has been found dead despite being guarded through the night.

Inspector Marlowe arrests Jackaby and Abigail and brings them in for separate police questioning.

Mrs. Morrigan is found murdered while Jackaby and Abigail are locked in prison, proving they could not be the killers.

Marlowe agrees to help, and Jackaby asks him to assemble every police officer in the town square.

In the town square, Jackaby publicly announces to the assembled officers that he believes the killer is one of them.

Abigail discovers Commissioner Swift crouching over a dead policeman in the woods and recognizes him as the murderer.

Jackaby throws Swift's blood-soaked hat into a fire, causing both the hat and Swift to burn to ash.

Abigail Rook arrives in New Fiddleham and is hired by paranormal investigator Jackaby to help solve the murder of journalist Arthur Bragg. They discover the killer drains victims of blood and has been committing murders across multiple cities. When Henderson is killed despite police protection, Jackaby and Abigail are arrested as suspects, only to be cleared when Mrs. Morrigan is murdered while they are locked in their cells. Jackaby deduces the killer is within the police force and stages a public confrontation in the town square. Abigail ultimately uncovers Commissioner Swift as the killer hiding behind his authority. Jackaby defeats Swift by burning his blood-soaked hat, and the case is closed.

The core murder investigation from first victim to final resolution.

Abigail encounters a strange man at an inn who deduces her entire travel route from Europe just by examining her.

Abigail pretends to faint to distract a police officer, allowing Jackaby to slip unnoticed into the crime scene building.

Jackaby notes deep claw marks in the apartment floors near Bragg's body, suggesting the killer was not fully human.

Abigail meets young officer Charlie Cane at the crime scene and is immediately drawn to him.

Inspector Marlowe warns Abigail that Jackaby is dangerous and advises her not to work for him.

Abigail returns to Jackaby's house alone and feels an unseen presence watching her as she explores the rooms.

A ghost suddenly appears and startles Abigail during tea, and Jackaby calmly introduces her as Jenny Cavanaugh.

Jenny arranges the guest room for Abigail and lends her clothes from her own old wardrobe.

Charlie recounts hearing a mysterious clinking sound in the hallway just before breaking in and discovering Henderson's body.

Jackaby and Abigail realize from their separate prison cells that everyone around them can hear the banshee's wail.

Jackaby places two coins on Mrs. Morrigan's closed eyes and recites a Latin prayer over her body.

Abigail snatches a lead sinker from Hatun's fishing gear as she runs through the woods in pursuit of Charlie.

Charlie in dog form attacks Swift to save Abigail but is stabbed by a sword concealed in Swift's cane.

Jackaby arrives in the woods and shoots Commissioner Swift multiple times while reciting a Latin incantation.

Jackaby presents Abigail with a custom leather detective's notebook, officially welcoming her as his partner.

Behind the main investigation, smaller but crucial moments reveal the world of New Fiddleham and its characters. Abigail uses her wits to gain access to crime scenes and proves herself a capable partner from the very first day. Jackaby's eccentric household comes to life as Abigail meets Jenny the ghost, discovers that Douglas the duck was once a man, and is given a room to call her own. Physical clues like claw marks and a mysterious clinking sound gradually point toward a monstrous killer hiding in plain sight. The climax brings desperate improvisation, as Abigail's thrown lead sinker distracts Swift long enough for Jackaby to arrive and finish the fight. The case closes with Jackaby gifting Abigail a detective's notebook, marking the true beginning of their partnership.

The hidden details and quieter moments that shaped the investigation.

Abigail abandons her planned return voyage to England and chooses instead to continue onward to America.

Jackaby explains to Abigail that his gift of second sight allows him to perceive the hidden supernatural world.

Mona O'Conner punches Jackaby in the face after he dismissively refers to her as simply a woman.

Commissioner Swift arrives to pressure Marlowe about the case, and Abigail notices his pompous manner and metal leg braces.

Hatun explains that her knitted shawl makes her unnoticeable to anyone who has a permanent home.

Jenny reveals that the duck living in the upstairs pond is Douglas, Jackaby's previous assistant transformed by a spell.

Jackaby deduces from Hatun's invisibility that the killer must have a stable home, significantly narrowing the suspects.

Jackaby warns Abigail that they may be in danger because they are investigating the killer exactly as Bragg had.

Jackaby tells Abigail privately from his prison cell that he believes the killer is a member of the police force.

Charlie arrives at the prison looking visibly ill, and Jackaby hints that he already knows Charlie's supernatural secret.

Charlie spasms and transforms into a large dog in front of the entire assembled crowd in the town square.

Abigail recognizes the clinking of Swift's metal leg braces as the same sound heard near both murder scenes.

Marlowe arrives at the fire and points a gun at Jackaby, convinced that Charlie, not Swift, is the monster.

Jackaby explains that Charlie comes from a nomadic shapeshifting family and details why each murder victim was specifically targeted.

Jackaby places Swift's iron leg braces on the commissioner's memorial coffin in a silent act of private defiance.

The story turns on a series of revelations and decisions that shift the investigation and the characters' understanding of the world. Abigail's choice to travel to America rather than return home sets everything in motion, and Jackaby's explanation of his second sight opens her eyes to the hidden reality around her. Each new discovery — a banshee's true purpose, a magical shawl, a transformed assistant, and a killer hiding behind civic authority — forces both characters to question their assumptions. The arrest becomes a pivot point when Jackaby privately names the police force as suspects, setting up the public confrontation to come. Charlie's involuntary transformation and Swift's unmasking bring the truth fully into the open, though not without terrible cost to Charlie. The novel closes with quiet gestures of defiance and solidarity that signal a lasting partnership between Jackaby and Abigail.

The key decisions, discoveries, and revelations that transformed the investigation.