It's the 9th book in the Gabriel Allon series. Released July 21, 2009, the cover depicts the House of Parliament and Big Ben in London. The cover of the paperback printing by Signet (July 2010) depicts St. Basil's Cathedral in Moscow.
Much of the story is set in Russia, where Gabriel Allon tries to rescue Russian defector Grigori Bulganov, who was introduced in an earlier book in the series. Bulganov had been kidnapped, and Gabriel Allon must save him from the clutches of Ivan Kharkov, also from the previous book.