When the president of Ng’ombwana visits London, Chief Superintendent Roderick Alleyn must navigate a high-stakes diplomatic security nightmare that culminates in a brazen assassination. Alleyn is tasked with protecting a head of state who insists on eschewing traditional security, placing the detective in the center of a volatile political environment. As the investigation unfolds, Alleyn must contend with competing interests from Special Branch, local tribal authorities, and the complex social dynamics of the embassy. The narrative, presented in Marsh’s signature third-person style, emphasizes the procedural rigor of the police while introducing an unconventional investigative partner in the form of a cat named Lucy Lockett.

This novel is widely regarded as a quintessential example of Ngaio Marsh’s ability to blend high-stakes political tension with the traditional tropes of the Golden Age mystery. Readers often highlight the clever inclusion of Lucy Lockett as a whimsical counterpoint to the otherwise serious and procedural nature of Alleyn’s police work. The book is frequently praised for its intricate plotting and the author's sharp observations regarding the social and diplomatic pressures of the era. It remains a staple for enthusiasts of classic detective fiction who appreciate a balance of dry wit and rigorous investigative detail.