An attempted assassination of a Russian diplomat at a London conference triggers a high-stakes investigation for Agent Craigie and the Department Z team. Craigie must navigate a complex web of international intrigue to protect delegates while identifying the professional organization behind the attack. The narrative follows a traditional procedural structure, focusing on the tactical maneuvers required to neutralize a sophisticated threat. As the stakes escalate, the team faces the physical danger of armed adversaries and the logical challenge of preventing a global political catastrophe.

Readers frequently highlight the fast-paced nature of John Creasey's writing, which emphasizes action and procedural detail over internal character exploration. Discussion often centers on the period-specific atmosphere of the Department Z series and the author's ability to maintain tension within a political thriller framework. Critics often note that the narrative relies on the competence of the protagonist to drive the plot forward through various crises. The book is recognized for its straightforward approach to the espionage genre, providing a clear look at the mid-century thriller style that defined the era.