Trial & Retribution XIV: Mirror Image (1)

A Metropolitan Police Commander and his magistrate wife, murdered in their own home. That's how Mirror Image opens: Jack and Honor Delany dead, jewellery gone from the house, and everything at first pointing to a burglary that turned fatal. It would be convenient if it stayed that way. Walker's superiors certainly want it to: with victims this senior and this well-known, the pressure for a quick result comes down on him almost before the bodies are cold.

The stolen valuables don't sit right, though. What sits even less right is the queue of people who profit from the deaths. Honor's brother Paul Mandray carries gambling debts that a legacy would clear nicely. Janet, the housekeeper, is named in the will too. And then there are the twin sons, Michael and Rory, identical in every visible respect, who stand to inherit a fortune.

Connor fixes on the twins, and you can see why. Identical brothers suspected of the same murder raise a problem the show clearly relishes: if two men look exactly alike and neither will give the other up, how do you ever prove which of them did what? Her suspicion is darker than mere opportunity. She starts to think they may have worked together on it, sharing the act between them so that patricide becomes a joint enterprise with an alibi built in.

Lynda La Plante wrote it and Michael Whyte directs, with David Hayman's Walker, Victoria Smurfit's Connor and Dorian Lough's Satchell doing the heavy lifting. The guest roster is unusually good: Michael Pennington as James Clayton QC, John Carlisle as Judge Cooper, Suzanne Bertish as Ms Newburgh, Olivia Hallinan as Charlotte Rogers, Michelle Fairley as Mrs Jenkins, Greg Hicks as the indebted Paul.

The first night is mostly scene-setting, but it's good scene-setting — money, grief and a family that can barely look at each other. The title does a lot of work here, and by the end of part one you'll have guessed at least some of what it means.