Overheard as I left Milton Keynes Theatre on Monday night after the Agatha Christie Theatre Company’s production of Murder on the Nile: “That’s why grandad didn’t come — because he remembered the end.”

Well, clever old grandad, I thought, for isn’t it traditionally said to be the case that no one ever remembers the end of a Christie story? Ogden Nash once wrote a poem that made this very point, identifying her novels as perfect desert island material because no matter how often you read one, the denouement is always a surprise.

Actually, I am beginning to wonder if it was Ogden Nash. The poem is certainly not in my big book of his work and I can find no reference to it on the Internet. Anyone help?

As I mention in my review of Murder on the Nile today, the play differs from the novel through the removal by Christie of Hercule Poirot. This was partly done because of the difficulty of finding a suitable actor to play him. Dame Agatha, with the proprietorial rights of any creator of a character, was never much impressed by those playing her sleuth. This began with Charles Laughton who was the first to play him on stage in Alibi (1928). “Entirely unlike Hercule Poirot,” said the writer.

One Christie murder mystery whose ending is said to be remembered by all is The Mousetrap. The truth of this I cannot vouch for through personal experience, since I have never seen it on stage or read the story on which it is based. Very few have read the story. It was withheld from publication while the play’s run continued, precisely in order that its plot should not become known. Sixty years later, it is still unpublished.

As a belated 60th birthday present to myself I had intended to travel to London to see the play. This will no longer be necessary, though, since it is going out on tour for the first time this autumn and will be visiting Milton Keynes between September 24 and 29.