The narrative begins at Sugden's Hotel in London, where the wealthy American Hugh Restington is found murdered under mysterious circumstances. Earl Ealing, who was scheduled to breakfast with him, immediately calls Scotland Yard. Inspector Blaikie takes charge of the case, discovering that Restington's real identity was Hugh Radlett, a billionaire who disappeared years earlier after a messy divorce. Radlett had recently returned from Russia with a valuable thirty-year mining concession signed by Lenin, meant to be developed in partnership with the Anglo-Asiatic Corporation. Suspicion initially falls on Radlett's missing secretary, Ivan Rosenbaum, a Russian agent who allegedly fled with the body hidden in a large trunk.
As the investigation deepens, Inspector Blaikie uncovers layer after layer of deception. Radlett's lawyer, Wilbraham Franklin, reveals details about the millionaire's vast fortune and a newly executed will that leaves everything to his loyal friend and partner, John Pasquett. Meanwhile, Lord Ealing maneuvers frantically behind the scenes to protect his own financial interests in the failing Anglo-Asiatic Corporation. The stock market fluctuates wildly as rumors spread regarding the validity of the concession, forcing the directors into high-stakes financial manipulation.
Pasquett arrives in London and immediately throws himself into the search for the killer, initiating a private hunt that spans from the smoky alleys of London to the industrial North. The police follow false leads, including the mistaken arrest of an innocent merchant by the Special Branch. Despite exhaustive searches of the crime scene and the empty hotel room, the body of Hugh Radlett remains missing, leaving the authorities to grapple with an elusive culprit.
The investigation ultimately exposes the deep-seated rivalries of post-revolutionary European politics and the ruthless nature of high finance. While the official pursuit of Rosenbaum hits a dead end when the suspect slips away to Russia, the financial empire envisioned by Radlett is successfully resurrected by Pasquett and Lord Ealing. The story concludes with a renewed partnership, leaving the ultimate fate of the millionaire's remains unresolved.
