Boris Ostrovsky, editor of the independent Moskovsky Gazeta, claims to have exclusive information about imminent terror threats to the West and Israel but only dares entrust his knowledge with the now-famous Gabriel Allon.

Gabriel's drive to uncover this terror threat leads him to Russia, where he must play by a new set of rules that challenge even his abilities as Israel's top intelligence fieldworker.

His encounter with Olga Sukhova, also of the Gazeta, confirms his suspicions that a Russian arms dealer has begun trafficking with well-known terror groups.

Olga reveals her source to be Elena Kharkov, the wife of alleged arms dealer Ivan Kharkov—an oligarch with strong ties to both the old and new Kremlin governments.

She entrusts herself to Gabriel’s team, informs them of Ivan’s underhanded dealings, offers to turn over his business records, and asks for help in ‘defecting’ from both her husband and her country's corruption.

She then travels to Russia with Gabriel's entourage and gathers the sensitive financial information required to prove her husband's complicity to the arms trafficking.

The task runs afoul, however, when Ivan's chief of personal security, Arkady Medvedev interrupts the operation and takes Elena, and later Gabriel, hostage.

The U.S. government secrets away Elena and her children, while the UK shelters Olga Sukhova and Grigori Bulganov; the latter two collaborate upon and publish an exhaustive account of Ivan's dealings.