That is a question concerning an army officer in the War Office tasked with combating subversive activities. But Captain Vernon Kell has more problems than the lack of funds and support from an oblivious government, and a superior fixated on the idea that Germans are the prime threat and demanding he supply proof. In the class-conscious British society of the Edwardian era, his biggest problem is that the staffers he has stand out in places where they have to be deployed — like a munitions factory from where plans are being stolen — are easily identified by the ruthless enemy and liquidated. Consulting Sherlock Holmes, living in retirement in the country, he is given a unique suggestion. And in this engrossing story, H.B. Lyle filly does justice to a prominent and promising character from Holmes’ world who had not yet got a place in the sun. The once chief of the force that served as the detective’s nearly invisible but highly effective eyes and ears on the London streets — Wiggins of the Baker Street Irregulars. But our young hero is reluctant to get back into government service after his experiences as a soldier. All that changes when his friend, a London police constable, is shot dead by a Russian archist after a robbery, and his own attempts to find who is responsible, among the closed, suspicious world of Russian emigres in the city, are both unsuccessful and potentially lethal.