Achilles Heel

Wexford and Burden take their wives to France for a holiday, which sounds restful and turns out to be anything but. On the trip they meet an alluring English couple, Philip and Iris Blackstock, and Reg, to his own evident surprise, becomes transfixed by Iris. The holiday idyll does what holiday idylls do in crime drama: it dissolves. Back home, the news arrives that the woman he could not stop watching has been kidnapped.

The episode's engine is that uncomfortable personal pull. Wexford has no official reason to care about the Blackstocks beyond the usual, and yet he cares a great deal, and the kidnapping drags the case into territory where his judgment is not at its most reliable. The professional machinery grinds into motion regardless, and the missing woman's fate becomes the kind of investigation nobody enjoys: personal, urgent and full of people who might be lying. The episode first went out on the 26th of December 1991, a Boxing Day instalment, and it stands alone in a season that had spent the autumn on multi-part stories. There is no three-hour build here; the whole story fits into a single hour, from the holiday meeting to the kidnapping, and the compression suits its anxious tone.

Stephen Dillane plays Philip Blackstock, and Kim Barclay is Iris, with Charlotte Howard as Linda Blackstock completing the family picture. André Oumansky's Ange, Julia Lane's Anna Ashby and Robert Hands' PC Stevens fill out the cast, and Louie Ramsay's Dora and Diane Keen's Jenny are along for the ride as the wives who watch their husbands descend into the case. Guy Hibbert wrote it, and Sandy Johnson directed, for release in 1991.

The episode is a reminder that a holiday is only a change of scenery for trouble. Wexford went to France for rest and came home with an obsession, and the kidnapping is the price of the holiday's one moment of distraction. The title says it all: the Achilles heel is not a case, it is a feeling, and Reg has found his.