Archangel by Robert Harris

Fluke Kelso was once a scholar of promise, but like so many in the highly competitive world of academia, he's never delivered. But one night, at a symposium in Moscow concerning the release of secret Soviet archives, he is approached by Papu Rapava, a former Kremlin bodyguard with a story to tell. No one but the desperate Kelso would believe the tale, for what Rapava describes is a sort of Holy Grail among researchers: an actual diary left by Joseph Stalin himself. Such an artifact, if it's genuine - and if Kelso can survive the fascist Vladimir Mamantov, who wants it for his own agenda - would be the coup of a lifetime for the discredited researcher. Before Kelso can learn the location of the diary, Rapava disappears, and Kelso's search for the former bodyguard leads him to the man's daughter, a whore selling herself in the new Moscow of drugs, corruption, and the Russian mafia. With an unscrupulous American journalist hot on their heels, a major of the new KGB close behind, and the shadowy Mamantov following them all, the two follow a trail that leads from Moscow's seedy underbelly to the industrial city of Archangel, where Russia once built her fleets of submarines, to a remote camp on the edge of the Siberian nothingness, and finally to a shocking conclusion that bites like the wind blowing off the tundra. What Kelso sees as the coup of his career might turn out to be the catalyst for an actual coup in Russia. There is a legacy behind the diary, a legacy of evil and death, and Fluke Kelso is unwittingly about to unleash it on the world.