Two deaths, ten years apart, give Flavia de Luce the distraction she needs at a time when her family are more remote and dysfunctional than usual. Especially when a bizarre series of deadly events is casting a long shadow over everyone at Buckshaw. For Flavia, a gruesome crime to solve is only one of the mysteries confronting her, as she begins to unravel the shocking revelations surrounding the mysterious disappearance of her mother. And as she starts putting the clues together, she discovers an extraordinary tale of espionage and betrayal that may also be the key to her own destiny.

兩場相隔十年的離奇死亡，讓遠離家人的芙拉維亞，正好能從更加疏遠的家人和破碎的家庭中轉移注意力。一連串迥異的死亡事件讓柏克蕭宅裡的所有人人心惶惶。但對芙拉維亞而言，隨著她抽絲剝繭解開母親失蹤的謎團，一樁慘絕人寰的罪案僅是她需要面對的謎團之一而已。她開始拼湊線索，並漸漸發掘一起傳聞中的間諜行動及背叛，而她自身的命運亦緊密牽連其中。