Agatha Mary Clarissa Miller was born on September 15, 1890, in Torquay, on the Devon coast of England. During the First World War she worked in a hospital dispensary, where she learned a great deal about poisons, and she put that knowledge to use for the next fifty-five years. She married Archibald Christie in 1914.

Her first novel, The Mysterious Affair at Styles, came out in 1920 and introduced a retired Belgian police officer named Hercule Poirot. The Murder of Roger Ackroyd, in 1926, made her famous.

That same year her mother died and her marriage came apart, and in December of 1926 she disappeared. For eleven days the newspapers were full of it and the police searched the countryside. She was found at a hotel in Harrogate, registered under another name. She never explained it, in her lifetime or in her autobiography, and I have always thought she was entitled not to. I don't speculate about it, and I'd ask you not to in your letters to me.

She divorced in 1928, and in 1930 married Max Mallowan, an archaeologist, and for years went with him on his digs in Syria and Iraq. You can feel the desert in several of the books. She also wrote six romantic novels under the name Mary Westmacott, which are worth a look for the curious.

In 1952 her play The Mousetrap opened in London. It has never closed. It is still running as I type this, forty-seven years later, and the audiences are still asked to keep the ending to themselves, which they do. She was made a Dame in 1971 and died on January 12, 1976.

She wrote sixty-six detective novels, more than a dozen collections of short stories, and a good many plays. I have read every one of the mysteries. I have not read every one of the plays, and I hope I live long enough to say otherwise.

Hercule Poirot came to England as a refugee in the first war and stayed for fifty-five years of cases. He is small, vain, fussy, proud of his moustache, and deeply kind underneath all of it. He doesn't crawl about with a magnifying glass; he sits and thinks, and he puts people in order the way he'd put books on a shelf. His friend Captain Hastings tells many of the stories and misses nearly everything, which is useful, since so do we. There are thirty-three Poirot novels and more than fifty short stories. His last case, Curtain, was written during the Second World War and locked away, and published only in 1975. When it came out, The New York Times ran his obituary on the front page. He is the only detective I know of who has had one.

Miss Jane Marple lives in the village of St. Mary Mead and knits. She has never been anywhere much and has seen absolutely everything, because every murderer reminds her of somebody in the village: the butcher's boy, the vicar's maid, a woman who once cheated at the flower show. Human nature is the same everywhere, she believes, and she is right. She first appeared in short stories in the twenties, and her first novel was The Murder at the Vicarage in 1930. There are twelve Marple novels. Her last, Sleeping Murder, was also written years ahead and came out in 1976, after Dame Agatha had died.

My verdict. Poirot has the better books. Five of my best twelve are his, and only four are hers. But if I could have one of them to tea, it would be Miss Marple, without a moment's hesitation. Poirot would rearrange my bookcase, and he would be wrong about the system.

So: Poirot for the puzzle. Miss Marple for the people. And I'll point out that Christie herself, from what she wrote over the years, got rather tired of Poirot, and never seemed to tire of her.

David Suchet's Poirot. The British series began in 1989, and we see it here on public television, on Mystery!. Mr. Suchet is Poirot. The walk, the voice, the vanity and the kindness, all of it exactly as I'd pictured it reading by flashlight in 1946. If you see one Poirot, see his.

Joan Hickson's Miss Marple. The BBC filmed all twelve Marple novels with her, starting in 1984, and those too came to us on public television. She was well into her seventies when she began, and she is perfect: sharp, quiet, a little fluttery when it suits her, and with eyes that miss nothing. I've watched A Murder Is Announced four times.

Murder on the Orient Express (1974). Sidney Lumet's film, with Albert Finney as Poirot and a cast of famous faces that runs most of the way down the train. Ingrid Bergman won an Academy Award for it. Dame Agatha went to the premiere in London, which was one of her last public outings. A handsome picture. Finney is a bit too much for me, but I'm in the minority.

The others. Peter Ustinov played Poirot in Death on the Nile (1978) and Evil Under the Sun (1982), and enjoyed himself. Margaret Rutherford's Miss Marple films in the sixties are delightful and have very little to do with Miss Marple. Angela Lansbury played her in The Mirror Crack'd (1980), a few years before she started solving murders every Sunday night on her own. And Billy Wilder's Witness for the Prosecution (1957), from a Christie story and play, is a superb film by any standard. Watch it before anyone tells you anything.