The assassination of former Russian intelligence officer Alexander "Sasha" Litvinenko in November 2006 -- poisoned by the rare radioactive element polonium -- caused an international sensation. Within a few short weeks, the fit forty-three-year-old lay gaunt, bald, and dying in a hospital, the victim of a "tiny nuclear bomb." Suspicions swirled around Russia's FSB, the successor to the KGB, and the Putin regime. Traces of polonium radiation were found in Germany and on certain airplanes, suggesting a travel route from Russia for the carriers of the fatal poison. But what really happened? What...