4:50 from Paddington

Mrs McGillicuddy is on the 4:50 from Paddington when she looks out of her window at exactly the wrong moment. In the train running alongside hers, a woman is being strangled. She tells anyone who will listen, and nobody believes her, because there is no body, no report, no trace of the woman at all. The police cannot find a corpse and have started to doubt the story.

But she told Miss Marple, and that settles it. Miss Marple does what she always does: she finds a way in. Lucy Eyelesbarrow is a professional housekeeper, sharp and resourceful, and she takes a position at a shabby country estate where the body has to have been dumped. The family there looks ordinary. That is the problem. Everyone in the house is carrying something, and the longer Lucy stays, the more the seams show.

The search takes them from the railway line to the estate, and the further in they get, the less the family wants them there. Miss Marple is used to that reception. A body nobody can find is usually hidden where somebody needs it hidden.

Agatha Christie and T.R. Bowen wrote it, Martyn Friend directed, and it went out on Christmas Day 1987. Joan Hickson is Miss Marple, and Mona Bruce is Mrs McGillicuddy, the witness whose story starts the whole business. David Horovitch's Inspector Slack is back in the thankless position of being wrong about the old lady. Juliette Mole is Anna Stravinska, David Beames is Bryan Eastley, Nicholas Blane is the Paddington porter, with Ian Brimble as Detective Sergeant Lake, Katy Jarrett as Mary, Leslie Adams as the desk sergeant and Rhoda Lewis as Mrs Brogan.

A railway thriller slowed to village pace, and all the better for it. The mystery of the body nobody saw turns out to be the least of the household's secrets.