Paterson and Clocks are faced with a horrific crime scene. A mother lies brutally murdered in her ransacked home. Beside her are the bloodstained bodies of the two police officers who were first on the scene. In the bedroom are the victim’s two children, a six-year-old boy and a baby, slaughtered as they slept.

And then comes the sound of breaking glass from the next room.

The killer is still there . . .

Paterson sets off in hot pursuit across the rooftops. But after a desperate chase, the killer escapes.

The following day, another woman is found dead in her flat, her decapitated body carefully posed in her living room, her wrists pierced by crucifixes.

Why were these women targeted?

Paterson and Clocks have never had to deal with a killer like this. A killer who shows no mercy. A killer who can’t be reasoned with. A killer who leaves no trace.

The bodies are piling up. To stop the carnage, the two detectives must break every rule in the book.

At the same time, married life is not turning out as Clocks had hoped, and his father has just given him some very bad news . . .