This is an outstanding work from a serious scholar of Russian history. I'll be interested to try one of his nonfiction books. The author's knowledge of period details, mindsets, and customs really makes this novel stand out. There are so many fascinating little extras.My summaries of the sections are deliberately vague, as I think it's essential to be in the dark about where the story is going for best enjoyment. All three of the parts are very nicely tied in with each other by the end of the novel.Part I: 1916--Sashenka Zeitlin is a willful and reckless 16-year-old. Her father is wealthy and influential, so the family is allowed to live in St. Petersburg rather than in the Pale of Settlement with the other Jews. Sashenka rejects the excesses and debauchery of her Tsarist parents and becomes a Bolshevik spy.Part II: 1939 Moscow--Sashenka is now married to a Party leader and has two small children. She has remained a loyal Party member for over 20 years and still supports Stalin and the Soviet system. Just when they think the purging and "The Terror" is over, the arrests and disappearances start up again. This time, Sashenka fears that she and her husband may be targeted.Part III: 1994 Moscow and London--Katinka, a young historian, is hired in London by Roza Getman to find out what happened to Roza's family in Russia during the years of Stalin's Terror. In the course of her research, Katinka stumbles upon Sashenka's story. This part of the book was what sealed the deal for me on the five-star rating. I could not stop reading. It's a great mystery with the clock running down and old-timers trying to keep their secrets safe.Overall very well written and engaging. There is some awkwardness here and there where it's clear the author hasn't quite made that transition from nonfiction writer to novelist, but nothing glaring. Mostly just places where the thoughts or dialogue don't sound true to the way normal people think and speak. It doesn't detract from the story. It just stands out now and then.