Book review: The Husband Poisoner, by Tanya Bretherton (Hachette). Agatha Christie’s first novel, The Mysterious Affair at Styles (1920), introduces her iconic Belgian detective, Hercule Poirot, and features her famous quip: “poison is a woman’s weapon”. Of course, poison — sometimes referred to as Inheritor’s Powder — is not gender specific. Rather, poison can simply