Feet Of Clay

There's a stakeout running, a gang robbing wealthy tourists, and Regan walks away from it. The reason is Alan Ember, played by Joss Ackland, who years earlier had been a helpful informant and is now a rich businessman with a phone call he can't stop hearing: his son Paul has been kidnapped, and the price is ten thousand pounds.

Regan goes to help. Against his advice, Ember pays the ransom, and the boy comes home. That should be the end of the story, and the episode knows better. The reunion soon turns sour, which is the quiet cruelty at the centre of Feet Of Clay: getting the child back solves nothing about what the kidnapping has stirred up in the family or about whoever set it in motion. A father who pays quickly is a father who will pay again.

Roger Marshall and Ian Kennedy Martin wrote it and Chris Burt directed, and the casting is unusually rich for a series four outing. Thelma Whiteley plays Margot Ember, Brian Capron is Colin, David Wilkinson plays Paul, and Cheryl Campbell appears as Erica Taylor. On the police side there's Geoffrey Palmer as Commander Watson, Philippa Gail as DCI Barton and Robert Oates as DI Jim Hinxman.

Ackland is the reason this one works. He gives Ember a wounded grandness, a man who built a respectable life on foundations he'd rather nobody inspected, which is where the title earns its keep. Regan owes him from the old days and you can feel the debt chafing; loyalty in The Sweeney is never free, it just defers payment. The tourist-gang stakeout can look after itself for an evening. Watching an old informant turn out to have feet of the usual material is the sort of irony the show handled without ever pointing at it.