Detective Mary Hume stares at the crime scene in confusion. She's in an empty flat. Peeling wallpaper. A bloodstained chair in the middle of the room. But no body.

Her sergeant hands her a burner phone. On it is a video clip. It shows a woman. Tied to the chair in the flat, a carving knife pressed to her throat. Placed in the woman's lap is a piece of cardboard. Written on it in blood-red is one word: DEADTOWN.

The phone was handed in to Charing Cross police station the day before. The woman in the video is Melissa Clarke. A true crime blogger famous for exposing London's most notorious cold cases.

Just what did Melissa dig up that got her killed?

To find the answers, Mary calls on maverick ex-police officer Raine. She can reach people—and places—that Mary can't. When a second body is discovered, the two detectives realize that someone is playing twisted mind games with them.

Can they pull the pieces of the puzzle together before more people die?