On a rainy November evening, a young woman hurries through the crowd in London’s historic Russell Square. Out of the darkness, someone jostles her, then brushes past. A moment later, she stumbles, collapsing against a tree. When a young mother finds her body and alerts the police, Detective Superintendent Duncan Kincaid and his sergeant, Doug Cullen, are called to the scene. The victim, Sasha Johnson, is a trainee doctor at a nearby hospital, and she’s been stabbed.

Kincaid immediately calls his detective wife, Gemma James, who has recently been assigned to a task force on knife crime. Along with her partner, detective sergeant Melody Talbot, Gemma joins the investigation. But Sasha Johnson doesn’t fit the profile of the typical knife crime victim. Single, successful, daughter of a black professional family, she has no history of abusive relationships or any connection to gangs. She had her secrets, though, and Kincaid uncovers an awkward connection to his Notting Hill friends Wesley and Betty Howard.

As the detectives unravel Sasha’s tangled relationships, another stabbing puts London in a panic, and Kincaid’s team needs all their resources to find the killer stalking the dark streets of Bloomsbury.