It started with a splash. Jimmy, a homeless veteran grappling with PTSD, did his best to pretend he hadn't heard it - the sound of something heavy falling into the Tyne at the height of an argument between two men on the riverbank. Not his fight. Then he sees the headline: Girl in Missing Dad Plea. The girl, Carrie, reminds him of someone he lost, and this makes his mind up: it's time to stop hiding from his past. But telling Carrie what he heard - or thought he heard - turns out to be just the beginning of the story.

'Jesus Christ. I found one.' These words are blurted over the phone to Constable Snowy Lane, who is preoccupied with no more than a ham sandwich and getting a game with the East Fremantle league side on Saturday. They signal the beginning of a series of events that are to shake Perth to its foundations. It is 1979, and Perth is jumping with pub bands and overnight millionaires. 'Mr Gruesome' has just taken another victim. Snowy's life and career are to be forever changed by the grim deeds of a serial killer and the dark bloom spreading across the City of Light.

Starting a new life in Snowdonia was always DI Ruth Hunter's dream. Until a twisted killer turned it into her worst nightmare. Detective Inspector Ruth Hunter lives with the pain of her partner’s mysterious and unsolved disappearance. About to hit 50, the veteran police officer trades in the crime-ridden streets of London for a more peaceful life in rural North Wales. But Ruth has barely settled into her new position in North Wales Police, when the body of a brutally murdered woman is discovered...with strange symbols carved into her skin.

Three years ago, DCI Laura Hart was the top hostage and crisis negotiator for the Greater Manchester Police. Then her husband was kidnapped. Despite her best efforts to reason with the criminals, he was brutally murdered. Now living on the Isle of Anglesey in Wales, Laura is slowly healing. Then she gets a call: armed drug dealers have seized a tourist boat—and her 10-year-old son Jake is on board. There’s no other negotiator available, and the police need her to step up.

Ruby Winter is surprised when her reclusive father invites a strange solider into their house. Intrigued, she tries to eavesdrop on their conversation, but is alarmed when she hears a fight break out. She dashes into the kitchen to save her dad, but he's not the one in trouble. The soldier has been stabbed and is bleeding out on the floor. Refusing her pleas to call an ambulance, her dad urges her to pack a bag—they have to run. As they try to escape her dad is shot and Ruby is chased by one of the soldier's comrades but is hidden by Lucas, a boy she has ignored up till now.