PositiveAir MailHagedorn draws from decades of scholarship, thorough archival research, and deftly FOIA’d F.B.I. reports to reconstruct the intricate network of Russian cells in midcentury America, a world of handlers and honey traps and tradecraft worthy of a prequel to The Americans. A veteran of The Wall Street Journal, Hagedorn is an impressive reporter, sparing no detail from the elements of the story to which she has access. And it’s without question a great story. The problem is that some of the juiciest bits—notably any real sense of Koval’s interiority, or the specific way he communicated intelligence to his handler—didn’t make the historical record. This is the fundamental challenge of writing about espionage: spies work hard not to leave a trace. And Koval was by all accounts an exceptional spook. Hagedorn is often left to speculate, relying on qualifiers such as \'must have\' or \'surely.\' Such sleights of hand are inevitable in narrative nonfiction—Ben Mcintyre’s Cold War histories are full of them—but in this case one can’t help wondering whether Koval successfully foiled not only the American authorities but also any attempt by posterity to satisfactorily account for his role in history.