A dying century. A killing presence. Present day: Nathan Jacob's life is coming apart. His adoptive father has passed away, leaving him grief-stricken. His only companion is his best friend, for whom he is falling more deeply every day. But Nathan is grappling with other demons: things half-formed and dark. Things that link him, somehow, to a series of horrific murders from the pages of history. 1890: Sergeant George Frohmell of the Dublin Metropolitan Police is running out of time. His city has become the hunting ground of a monster who preys on prostitutes and leaves them butchered in back alleys. As the bodies mount and the politics of Victorian Ireland come to the fore, Sergeant Frohmell must find his man – or lose everything.