December 1940. With the Luftwaffe pounding the city nightly, Londoners seek refuge in underground stations. Aldwych has been taken out of service to provide shelter for the British Museum's priceless Elgin Marbles, as well as civilians escaping the bombing. When the body of a young man is discovered on the tracks, wearing evening dress but barefoot, Detective Chief Inspector Coburg and Sergeant Lampson are on the case. Before long, more bodies are discovered, and Coburg's wife Rosa becomes a target for the brutal killer.

Hours later, the man’s cold body lies in the city mortuary, alongside the woman he couldn’t save. And his sister, unconventional nurse Gemma Tate, tracks down troubled police inspector Sebastian Bell to unravel the truth. Sebastian has enough pressure to solve the murder of an aristocratic heiress without Gemma meddling in his case. But the cryptic sentences she brings him from her brother’s notebook could be a crucial lead. If only they knew what “milky way” meant.

England, 1925. After years shut away from the world, former detective Lord Edgington of Cranley Hall plans a grand ball to celebrate his seventy-fifth birthday. But when someone starts bumping off members of his scheming family, the old man enlists his teenage grandson to help find the killer, before one of them is next.

May 1915. As zeppelin bombs fall on London and with the sinking of the Lusitania, anti-German hysteria reaches fever pitch and attacks on German immigrants surge. Not even the West End of London is immune. Jacob Stein's bespoke tailoring business comes under brutal attack, leaving his safe ransacked, his daughter, Ruth, raped and Jacob dead.

London, 1851. With the opening of the Great Exhibition at hand, interest in mounting in the engineering triumphs of the railways, but not everyone feels like celebrating. In an audacious attack, the London to Birmingham mail train is robbed and derailed, causing many casualties. Planned with military precision, this crime proves a challenge to Detective Inspector Robert Colbeck who fights to untangle a web of murder, blackmail and destruction.