Sent to Vienna to authenticate a painting, the art restorer and sometime spy Gabriel Allon is sidetracked by a photograph that throws his world upside-down. Could it really be the face of a man who during the last days of World War II had brutalized his mother on the Death March from Auschwitz? Questions abound when Allon, driven by an intensity he had not felt in years, begins to investigate, discovering in the process that the hunt for one man is a hunt for many-and a network of unimaginable evil spanning sixty years.