When the Home Secretary dies unexpectedly following a successful surgery, Chief Detective Inspector Roderick Alleyn must navigate a web of professional rivalries and personal vendettas to uncover the truth. The narrative follows Alleyn as he investigates the high-stakes environment of a private nursing home, where the surgeon and his nurse both harbored clear motives for the victim's demise. The story unfolds through a traditional third-person perspective, emphasizing the methodical collection of clues and the interrogation of suspects within a confined, clinical setting. Alleyn faces the challenge of distinguishing between medical malpractice and calculated murder while managing the social complexities of the British elite.

This novel is widely regarded as a quintessential example of the Golden Age detective story, praised for its intricate plotting and sharp character observations. Readers often highlight the clever interplay between the medical setting and the criminal investigation, noting how Marsh uses the clinical environment to heighten the tension. The character of Roderick Alleyn is frequently cited as a sophisticated and compelling lead who brings a calm, analytical presence to the chaotic circumstances. The work remains a staple for enthusiasts of classic British crime fiction who value logical puzzles and period-specific social commentary.