When a wealthy woman dies under suspicious circumstances in a private clinic, Superintendent Roderick Alleyn must navigate a web of professional secrets and personal vendettas to uncover the truth. The protagonist, Superintendent Alleyn, arrives to investigate a death that initially appears natural but quickly reveals signs of foul play. He faces a closed circle of suspects, including medical staff and family members, each harboring motives that complicate the investigation. The narrative follows a traditional procedural framework, emphasizing logical deduction and the systematic interrogation of witnesses within the confined setting of the clinic.

This work is widely regarded as a quintessential example of the Golden Age detective novel, showcasing the author's mastery of the classic whodunit format. Readers typically praise the intricate plotting and the sophisticated, urbane characterization of Superintendent Alleyn. The narrative is noted for its balance of clinical investigation and social observation, reflecting the author's background in theater and literature. Critics often highlight the clever use of the medical setting to create a confined, high-stakes environment for the mystery to unfold. The book remains a staple for enthusiasts of traditional British crime fiction who appreciate a puzzle-driven narrative.