Worth A Million

John Watt has the plans for a robbery. He knows the organiser, Jim Ryland, he knows the method, and he has the paperwork to prove it. What he does not have is the address. It is the sort of job that needs a getaway route, a crew and a postcode, and the postcode is the only piece missing. So he brings in Billy Cooper, one of Ryland's associates, and sits him in the interview room, where Cooper cheerfully admits the job is worth a million pounds and then refuses to say where it is going to happen.

But the whole episode is that interview, more or less. Watt wants one piece of information, Cooper enjoys having it, and the two of them circle each other while the squad waits on the other side of the glass. Hawkins, Evans and Snow fill the gaps in the station, and Morris Perry's Ryland hovers as the man whose name started it all, even though he never quite gets the centre of the frame.

There is something satisfying about a mystery reduced to a single withheld detail. No map and no bodies, just a man who knows something and a chief superintendent with the patience to sit in the room until it comes out. The title tells you what the job is worth; the episode is about what it costs Cooper to keep the secret. William Maxwell plays him with a knowing shrug that makes the stand-off watchable for a full hour.

The smaller parts are filled by the likes of Eric Mason, Lloyd McGuire, Derek Martin, decades before EastEnders, and Terry Walsh, each contributing a face and a few lines to the pressure-cooker atmosphere.

Matthew Robinson directs a script by Robert Barr and Elwyn Jones that never leaves the building, and the episode makes a virtue of that. Nobody runs anywhere. The chase is conducted in chairs. It is a small, neat piece, and the stillness is the point.