The snow is falling on the ancient streets of Rome. And in the heart of the city, under the Pantheon's great dome, a woman's body lies on the marble floor, carefully positioned with a gruesome carving on her back. Arriving at the scene, Detective Nic Costa is unprepared for what he finds, nor for the intervention of US agents with a take-no-prisoners style and a shocking story to tell: the killer has struck before, in monuments all over the world, leaving the same cryptic message carved onto the bodies of the victims. As the murder leads to more grisly slayings and the team of veteran Roman cops clash with the Americans, Nic is pulled into a harrowing search for the truth...a search that will take him into a shocking conspiracy – and a dark episode in a nation's long-forgotten past.