Based on the best part of a decade's reporting, as well as extensive interviews with those closest to the events (including the murder suspects), and access to trial evidence, Luke Harding's A Very Expensive Poison is the definitive inside story of the life and death of Alexander Litvinenko. Harding traces the journey of the nuclear poison across London, from hotel room to nightclub, assassin to victim; it is a deadly trail that seemingly leads back to the Russian state itself.