A Simple Sacrifice (2)

The hunt for the truth about Annie Keel gets a push from an unexpected quarter: an anonymous letter writer, who demonstrates to Boyd that Annie wasn't the only person present at the murders. Whoever they are, they know things the original trial never heard. Their motives stay opaque, which keeps Boyd and everyone else slightly off balance. Help from a stranger is a gift and a problem in equal measure.

The team's other priority is finding Annie's son, who was present when the killings happened. A child at the scene twenty-five years ago is now an adult who may or may not remember it, may or may not want to be found, and the episode handles that search with more care than urgency, which suits the material. This was never going to be solved by racing anyone.

What accumulates instead is a fuller picture of how much the first investigation left untouched. If Annie had company that night, then her confession wasn't just false, it was constructed, built to keep somebody else out of the frame. The people around her, the Mantels among them, all knew versions of the story, and none of those versions quite agree. Harriet Walter keeps Annie fascinating even in a quieter hour, holding everything behind that flat calm of hers while the case rearranges itself around her.

Barbara Machin and Simon Mirren wrote it, Robert Del Maestro directed, and the cast carries over intact: Trevor Eve as Boyd, Sue Johnston as Grace Foley, Holly Aird as Frankie Wharton, Claire Goose as Amelia Silver, Wil Johnson as Spencer Jordan, Simon Kunz as DAC Ralph Christie, Cal MacAninch as Sam Keel and Alex, Lynda Bellingham as Mary Mantel and Anthony Valentine as Patrick Mantel.

A middle episode that earns its place by narrowing rather than exploding. The anonymous letters are a neat device too, since they let the past speak directly into the present, which is the whole trick of this show in miniature.