"The Mysterious Affair at Styles," which features the introduction of one of Christie's most beloved characters, Hercule Poirot"The Secret Adversary," which features the introduction of Tommy and Tuppence, who were featured in three other Christie works.

    A refugee of the Great War, Poirot has settled in England near Styles Court, the country estate of his wealthy benefactor, the elderly Emily Inglethorp. When Emily is poisoned and the authorities are baffled, Poirot puts his prodigious sleuthing skills to work. Suspects are plentiful, including the victim’s much younger husband, her resentful stepsons, her longtime hired companion, a young family friend working as a nurse, and a London specialist on poisons who just happens to be visiting the nearby village. All of them have secrets they are desperate to keep, but none can outwit Poirot as he navigates the ingenious red herrings and plot twists that contribute to Agatha Christie's well-deserved reputation as the queen of mystery.Librarian's note: the first 5 Christie mysteries featuring Poirot are: 1) The Mysterious Affair at Styles, 1920; 2) The Murder on the Links, 1923; 3) The Murder of Roger Ackroyd, 1926; 4) The Big Four, 1927; and 5) The Mystery of the Blue Train, 1928. There are many short stories and a collection featuring Poirot in this period as well. Each novel and short story has its own entry on Goodreads.