Moscow, 1965. When Leo Demidov's worst fears are realised and a tragic murder destroys everything he loves, he demands only one thing: that he is allowed to find the killer who has struck at the heart of his family.

Crippled by grief, his request denied, Leo sees no other option than to take matters into his own hands, even though he is thousands of miles from the crime scene.

In a thrilling story that takes us from the backstreets of 1960s New York to the mountains of Afghanistan in the '80s, Leo will stop at nothing as he hunts the one person who knows the truth: Agent 6.