After a short leave, Inspector James Hadley returns to Scotland Yard in September 1882 and is summoned to the Commissioner's office, where he is informed that Charles Barrington, a high ranking official at the Foreign Office, has been found murdered alongside the naked body of a young man. The Commissioner demands that the investigation should be conducted in secrecy as Barrington was involved in high level negotiations with the Russian Embassy regarding British troop deployments in Afghanistan. The fact that Barrington was unmarried and a sodomite adds to the need for utmost secrecy in the investigation. Suspicion falls on the Russian Nihilists, who murdered Countess Helena Petrovna in Hyde Park a year previously, but that is soon discounted as a mysterious young man called Roger Freeman, who visited Barrington at the Foreign Office, becomes the prime suspect. As the investigation proceeds, Countess Natasha Petrovna, the sister of the murdered Countess, arrives at Scotland Yard to report the disappearance of her fiance, Dimitri Viralovski, who is identified as the naked man found murdered with Barrington. As Viralovski was a relation of the Russian Ambassador, the Embassy Chief informs Hadley that his Cossack security men will be searching for the killer, which complicates the investigation. After attempts to trace Roger Freeman fail, Sergeant Cooper has a lead to the suspect when he sees a male impersonator singing at a music hall. Hadley confronts the killer and is attacked before overcoming the assailant. At the trial, the killer pleads guilty, but insane and is sentenced to life imprisonment in a secure mental institution.