Something Nasty Down Below

An elderly woman walks in with a story that should be impossible: she has just seen her husband, a man supposed to have gone down with his submarine nearly forty years ago. Maggie Forbes takes it seriously, and the deeper she digs, the worse the truth gets. The submarine was never lost at sea. The crew mutinied, killed their officers, and vanished with the gold the boat was carrying.

The men who did it are in their seventies now, living on forty years of stolen money, and they are not too old to kill again. The episode does a good line in menace from characters who look like anybody's grandfather, which is exactly the point. The calm surface and the violence underneath are the same thing. There is something properly chilling about the idea that the past can surface like that, wearing a friendly face.

Don Houghton wrote it and John Frankau directed. Jill Gascoine's Maggie leads the investigation, with Peter Tilbury as Malcolm Proby, Ken Sharrock as the Skipper, Fraser Downie as the Engineer, Julia McCarthy as Slo Hawkins, Sally Mates as the Ward Sister and Linda Regan as the Naval Computer Operator, while Rosalyn Landor's Pru and Leslie Ash's Fred keep the unit running. It went out in May 1985, midway through the first series. The unit usually works London streets and office blocks, so a submarine interior counts as a genuine change of scene. Don Houghton, who wrote it, also wrote Frightmare later in the same run, another episode that finds its menace close to home. The naval setting gives the episode a good ration of uniforms and jargon, but the story underneath is a family tragedy forty years old.

The submarine business gives the show a mystery with a forty-year-old secret at its heart, which is a gift. And the old woman's grief, which starts the whole thing, is never treated as a joke. It is the reason any of it matters. There is a proper chill in watching men who got away with murder back in the 1940s try to keep it that way.