Sounds Sinister

Blackmail usually works in private. The pirates behind this one work on the airwaves, which gives "Sounds Sinister" a neat period twist: you cannot hush up a secret that has already been broadcast. Key public figures are having their dirty linen washed in public by a pirate radio station, and the humiliation is the weapon. Craven and Haggerty have to find who is running the transmitter before the next scandal goes out.

The investigation takes the pair into the shabby corners of outlaw broadcasting, and the script makes room for Detective Sgt. Isobel Ross to get properly involved. Claire Nielson's Ross ends up behind the microphone herself, an undercover posting that must have given her second thoughts about the phrase "going undercover." It is the kind of assignment that sounds like a lark until you are the one on air, and the episode is the better for letting her carry some of it. John Carson's Phillip Weston, Stanley Meadows's Max Levinson, Peter John's Pugh, Heather Page's Anna Maslyn, Peter Cleall's Stuart Barnes and Antony Webb's Irving Shannon all circle the station and its targets, and nobody involved looks entirely sorry for themselves.

David Butler wrote it, Terry Green directed, and the episode moves at a brisk clip. The pleasure is period rather than procedural: this is 1974, when radio still felt like something you could seize, and the idea of secrets shouted over the air to the whole country lands harder than it would now. There is a pleasing absurdity to the whole setup, a scandal being broadcast to everyone who wants to hear it.

But radio was made for this sort of mischief, and the show knows it. It is a tidy hour with a good gimmick, and the gimmick carries it. That is not faint praise; a blackmail plot that works over the airwaves is a nicer idea than most thrillers this age manage.