Set in the English countryside in 1950, it features Flavia de Luce, an 11-year-old amateur sleuth who pulls herself away from her beloved chemistry lab in order to clear her father in a murder investigation.

As the novel opens, Flavia Sabina de Luce schemes revenge against her two older sisters, Ophelia (17) and Daphne (13), who have locked her inside a closet in Buckshaw, the family's country manor home located in the English village of Bishop's Lacey.

Flavia has braces and pigtails like a typical 11-year-old girl, but she is also a brilliant amateur chemist with a speciality in poisons and a fully equipped, personal laboratory on the top floor of her home.

Flavia is especially jealous of her oldest sister because, at 17, she is the only one of the three girls with memories of their mother, Harriet, a free spirit who disappeared on a mountaineering adventure in Tibet 10 years earlier and is presumed dead.

Mysterious events begin to occur when Mrs. Mullet, Buckshaw's housekeeper and cook, discovers a dead jack snipe on the porch with a Penny Black stamp pierced through its beak.

When Colonel de Luce is arrested for the crime, Flavia takes to her bicycle, Gladys, and begins an investigation in the village of Bishop's Lacey, interviewing suspects, gathering clues, and compiling research at the library, always staying ahead of Inspector Hewitt and the police department.

The suicide victim, housemaster and Latin scholar Grenville Twining, and the red-headed stranger in the cucumber patch, Horace "Bony" Bonepenny, both uttered "Vale" as a last word.

[7] In the spring of 2006, Bradley had been working on a different book[8] set in the 1950s, when the plot developed to include a detective character arriving at a country house to find a little girl in the driveway, sitting "on a camp stool doing something with a notebook and a pencil.

"[9] When Bradley's wife heard author Louise Penny, a 2004 Debut Dagger award runner-up,[10] on the radio talking about the British crime-writing competition,[11] she encouraged her husband to enter.

"[19] Marilyn Stasio for The New York Times Book Review agreed, proclaiming Flavia "impressive as a sleuth and enchanting as a mad scientist," but "most endearing as a little girl who has learned how to amuse herself in a big lonely house.