The Mysterious Affair At Styles
This was the novel that launched Agatha Christie's career. It was first published in the United States in 1920 and then in the United Kingdom a year later. Agatha was encouraged to write it by her sister. It was written during World War I when Agatha was working at a hospital in Torquay as a pharmacist. She had many long night time hours which filled with the writing of this book. She also used her extensive knowledege of poisons in this novel and those that came later. The book was dedicated to her mother.
The book centres on the murder of matriarch Emily Inglethorpe and there are elements of the locked room mystery in the circumstances of her death as all doors to her room appeared to have been bolted from the inside. The book introduces Poirot who is a Belgian refugee with a long and illustrious detective career behind him; upon arrival in England he has been assisted by Emily Inglethorpe and is therefore committed to revealing exactly who the killer is.
The book is narrated by Captain Hastings who has been invalided from the Wester Front and who at the time of relating the story is 30 years old. Poirot is considerably older. There are echoes of Conan Doyle's Dr Watson in this way of narrating the story. The book is firmly anchored in the period of World War I and there is reference to the surrealness of events in England when not so far away the horrors of the tenches were playing out in northern France. Interestingly, the book contains characters such as the young Cynthia who like Agatha was serving in a hospital dispensary as a VAD. Yet, there is no explanation why some of the male characters such as Hastings' contemporaries Lawrence and John are not serving.
As you would expect there are plenty of red herrings in the story and your suspicion inevitably falls on one and then another of the characters. The eventual resolution is clever and the very last loose end is tied up on the last page