In the final book of the fantastic trilogy that started with Child 44 Tom Rob Smith continues to follow the adventures of ex Soviet secret service agent Leo Demidov. Each of them has been a great page turner with intelligent plots based around exciting and grim historical times and Agent 6 is no different, bringing to culmination a story that crosses to the U.S and has devastating repercussions for Leo and his tenuous family life. 
A really great end to a - for want of a better genre description -
trilogy of thrillers. If you haven't read Tom Robb Smith's first books in the series I kind of envy you as discovering these kinds of books doesn't happen all that often.

- Ben