Trial & Retribution IV (1)

The tables turn in a way that must have given David Hayman a very good season. Pat North is handed an eight-year-old murder case, the kind of cold file everyone assumes is finished, and told to look again. The point is that it might clear a man convicted all those years ago. Eight years is a long time for a mistake to sit in a file. And the deeper she goes, the more uncomfortable things get, because the officer who ran the original inquiry was Walker, her partner and her boss. Now he is her suspect.

North does what the job demands. She suspends him, and Walker, stripped of his warrant card and his standing, has to go back to where he came from to dig up the evidence that will clear him. It is a strange and lonely quest: a senior detective reduced to knocking on old doors and old memories, trying to prove that his own investigation was not a cover-up. His career, his relationship and his reputation are all on the line, and the episode lets him sweat. North, meanwhile, has to live with what she has done, even if she is right to have done it.

Lynda La Plante wrote it, Michael Whyte directed. It first aired in October 2000. The guest cast is strong: James Wilby's James McCready, Corin Redgrave as Robert Rylands, Christopher Neame's Ben Duffield, and Steven Hartley as Gary Meadows, with the De Wolf twins sharing the role of Fiona Meadows at seven. Kate Buffery carries the whole thing on her shoulders, and the scenes where North has to look her partner in the eye and do her duty anyway are the best in the episode.

There is real satisfaction in watching a cold case get its dust blown off. North solves it the way these things are solved, file by file, interview by interview, and it takes an age. That is the show's quiet faith, and it has never been more personal than here.