Set in the 1950's Soviet Union, but inspired by the much later story of real life serial murderer Andrei Chikatilo, Child 44 is in various ways a crime story, an exploration of truth, an examination of the tension between integrity and self-preservation, and the effects of fear on human relationships.
Most reviews I've read have trumpeted the novel as a thriller, but its greatest strength lies in its portrayal of the world of Stalinist Russia, one permeated by fear and falsehood. Smith is at his best in delving into the corrosive effects on human beings of the time and place, whether the horrible expedients to avoid starvation in the Ukraine, the denunciation of innocents in the basement torture chambers of the Lubyanka, or the mistrust bred into even the most intimate of human relationships.
It is the clash between these realities and the fantasy of official propaganda which fuels much of the plot. In this worker's paradise, nothing is as it seems. One of the many fictions perpetuated by the political apparatus is that there is no crime, no murder, as Leo Demidov, decorated member of the State Security Force at the beginning of the novel, prods a colleague whose son has been killed. By the end, Leo, demoted and disillusioned, comes full circle, risking his life and that of his wife in a frantic, all out hunt for a child predator. Ironically, it is in losing all that Leo gains his humanity.
Because of its setting and story, the comparison to Gorky Park is a natural. For my money, Martin Cruz Smith's novel is the better read. The plot here is too gimmicky, the characters not as developed, not to mention that Smith's protagonist is originally one of the bad guys. At the same time, Child 44 is in a different class altogether and is probably the better book. It rises above genre as it questions how far a human being will go to assure his survival.
If you like thrillers, have an interest in Russian history, or have a couple of hours to kill, you could do much worse that Child 44.