Agatha Christie up to the last chapter, then decided who the most unlikely suspect was, after which she would go back and make the necessary changes to "frame" that person. However, John Curran's "Agatha Christie: The Secret Notebooks" describes different working methods for every book in Christie's bibliography, contradicting the claim by Aldiss. Christie's mature novels, from 1940 onwards, often have titles drawn from literature. Four are from Shakespeare: Three are from the Bible: Another six are from other works of literature: In such cases, the original context of the title is usually printed as an epigraph. Similarly, the title of Christie's
Agatha Christie as the End", set in ancient Egypt, the culprit is killed by one of the few surviving characters before he can claim another victim. In some stories, the question remains unresolved of whether formal justice will ever be delivered, such as "Five Little Pigs" and "Endless Night". According to P. D. James, Christie often, but not always, made the unlikeliest character the guilty party. Savvy readers could sometimes identify the culprit by simply identifying the least likely suspect. On an edition of "Desert Island Discs" in 2007, Brian Aldiss claimed that Christie had told him that she wrote her books