From a review of Agatha Christie's Secret Notebooks: Fifty Years of Mysteries in the Making: "The contents of the notebooks are as multi-dimensional as their Escher-like structure. They include fully worked-out scenes, historical background, lists of character names, rough maps of imaginary places, stage settings, an idle rebus (the numeral three, a crossed-out eye, and a mouse), and plot ideas that will be recognizable to any Christie fan: "Poirot asks to go down to country—finds a house and various fantastic details," "Saves her life several times," "Inquire enquire—both in same letter." What's more, in between ominous scraps like "Stabbed through eye with hatpin" and "influenza depression virus—Stolen? Cabinet Minister?" are grocery lists: "Newspapers, toilet paper, salt, pepper …" There was no clean line between Christie's work life and her family life. She created household ledgers, and scribbled notes to self. ... Even Christie's second husband, the archeologist Sir Max Mallowan ... jotted down calculations [in it]. [Her] daughter Rosalind practiced penmanship, and the whole family kept track of their bridge scores alongside notes like, "Possibilities of poison … cyanide in strawberry … coniine—in capsule?"
Makes one wonder about what makes the notebooks secret.
The book actually seems to consist of excerpts from the 73 notebooks Christie kept during her writing careers. The Chaos seems to have been the result of her habit of keeping many notebooks concurrently and writing writing hapharzdly in all of them over many years.
Serendipity ruled! Or did it?
In any case, I will probably buy this book (soon), even though I have not read an Agatha Christie novel in more than forty years.