"On the morning after the Venice Preservation Society's annual black-tie gala, art restorer and legendary spy Gabriel Allon enters his favorite coffee bar on the island of Murano to find General Cesare Ferrari, the commander of the Art Squad, eagerly awaiting his arrival. The Carabinieri have made a startling discovery in the Amalfi villa of a murdered South African shipping tycoon--a secret vault containing an empty frame and stretcher matching the...