For two years, London Detective Inspector Kieran Shaw has been building evidence against an organized network, the Eardsley Bluds, and Operation Perseus is about to make its arrests. So even when a low-level Bluds member is stabbed to death on Gallowstree Lane, Shaw's priority is to protect his operation. But there's a witness to the murder, 15-year-old Ryan Kennedy, and he has his own ideas about what's important. As loyalties collide, Shaw's old adversary DI Sarah Collins steps in and threatens everyone with a connection to Gallowstree Lane.