Trust nobody.

Child 44 by Tom Rob Smith

Taking place in Stalin's Russia in the '50's, Leo Demidov, a highly-regarded State Security officer, has discovered a series of child murders. This fast-paced thriller takes us on the hunt for the killer along with Leo and his wife, Raisa, while they themselves are being hunted down and suspected of disloyalty to the government. People are suspicious of everyone they see, nobody trusts anybody else, the government denies that any crime exists, people are shot for just knowing someone who is being suspected of any wrong-doing....all true occurrences under Stalin's rule. This is a tightly-wound story, loosely based on a true crime, and I recommend it to anyone looking for a tense experience!