The Moving Finger (2/2)

The second half pays off Miss Marple's oldest piece of wisdom: a murderer does not stop at one. More bodies turn up in the sleepy town, and the poison pen letters are still landing, and the hunt narrows toward whoever the letters were really aimed at all along. The first half ended with letters and bodies piling up in step, and the second begins with the pile getting higher. Each new discovery proves her instinct, that one murder will always follow another, at a growing cost to the town.

But this time the danger is personal. Miss Marple herself is menaced, which in these stories usually means she is close to the truth. The dread builds steadily as the evidence piles up, and the amateur sleuth finds herself in uncomfortable proximity to genuine peril. The poison pen's cruelty is methodical now, each letter aimed at a weak spot its target did not know was visible. The truth about the murders and the letters emerges together, and it has been hiding in plain sight all along, in an ordinary house full of ordinary resentments. The person behind the letters has been among the town the whole time, smiling at the right moments.

Agatha Christie and Julia Jones wrote it and Roy Boulting directed, with the second half going out on 22 February 1985. Joan Hickson is Miss Marple, with Michael Culver as Edward Symmington, Deborah Appleby as Megan Hunter, Andrew Bicknell and Sabina Franklyn as the Burtons, Richard Pearson as Mr Pye, Hilary Mason as Emily Barton, Dilys Hamlett and John Arnatt as the Calthrops and Sandra Payne as Eryl Griffith.

The moving finger writes, and having writ, moves on. In this town it left a trail of letters and a pile of bodies, and it took a woman with a knitting bag to follow it home. The period charm survives the body count, which is no small thing. The solution is the kind that sends you back to the earlier scenes to check, which is the best compliment a mystery can be paid.