On a spring morning in 1951, eleven-year-old chemist and aspiring detective Flavia de Luce gathers with her father and sisters at the railway station, awaiting the return of her long-lost mother, Harriet. Yet upon the train's arrival in the English village of Bishop's Lacey, Flavia is approached by a tall stranger who whispers a cryptic message into her ear. Moments later, he is dead, mysteriously pushed under the train by someone in the crowd. Who was this man, what did his words mean, and why were they intended for Flavia? Back home at Buckshaw, her family's crumbling estate, Flavia follows a trail of clues to unravel the deepest secrets of the de Luce clan -- and unmask a killer.