The Mysterious Affair at Styles is Agatha Christie's debut novel and the first appearance of her legendary detective, Hercule Poirot. Set in an English country house, the story revolves around a suspicious death by poisoning, hidden motives, and carefully concealed secrets. With meticulous plotting, logical clues, and a fair-play mystery structure, Christie established the blueprint for modern detective fiction. Elegant, clever, and timeless, this novel remains an essential read for fans of classic mysteries and crime literature.