Faultlines

Lynne Stott's body is found wrapped in bin bags on a building site. The details nudge Janet towards a horrifying conclusion: this could be another victim of the serial killer who murdered Veronica nearly forty years earlier. The case she has carried since childhood may not be closed after all.

Rachel, meanwhile, bumps into Martine Cooper, an ex-juror, and is shocked to learn the woman had an affair with Nick during a trial in which his client was acquitted. A desperately worried Nick does everything in his power to persuade Rachel to keep the knowledge to herself. For a man who usually talks his way out of things, he is suddenly all pleas and promises. She decides not to use it against him. It is one of her better decisions, and it barely registers, because the other case is about to explode.

Rachel follows up Janet's hunch instead, and the facts she turns up are bad. Janet is in real danger, and there is no time to warn her properly. Janet comes face to face with the killer, who escapes after seriously wounding her with a knife. The knife wound is not the worst of it; the failure to catch him is. The hunt for Veronica's murderer has cost Janet her safety, and the team its composure.

Sally Wainwright, Diane Taylor and Suranne Jones wrote it, Benjamin Caron directed. Suranne Jones's Rachel and Lesley Sharp's Janet carry the episode, with Amelia Bullmore's Gill, Jennifer James as Martine Cooper, Martin Miller's DI Phillips, Nicola Potts as Caitlin Scott, and Nicholas Gleaves, Ben Batt and David Prosho in support.

The past is the real villain here. Nick's secrets and a decades-old killer end up in the same dark room, and Janet pays for both. But it is the episode where the show stops teasing the Veronica story and starts sharpening it.