Why did Agatha Christie write "And Then There Were None''

Christie wrote many of her most famous novels, including And Then There Were None in the first half of the twentieth century. She served as a nurse in both World Wars. One explanation for the success of her novels is that the murder mystery and detective fiction genre is principally a genre that seeks to instill sanctity to life through an exploration of the horrors of death, and to create a right moral order within a fictionalized world. This fictionalized moral order replaces the depraved moral order of reality. According to some critics, Christie's audience in the years following the World Wars craved a world of moral order and justice. Christie's fiction offered this moral vision. In addition, of course, her fiction also offered ingenious plot twists and a keen eye for the details of crime that left readers guessing and full of suspense until the final pages.