In a hushed Vatican Reading Room, the scene is shocking: a crazed professor shot dead after brandishing evidence of a grisly crime. Moments later, two bodies are found in a nearby church, each with a gruesome calling card from their killer .

Detective Nic Costa is one of the first on the scene. A cop who barely looks his twenty-seven years, Nic soon meets a woman who will dominate both his thoughts—and his investigation. A cool, beautiful professor of early Christianity, Sara Farnese was in the Vatican Library on that fateful day, a witness to her colleague’s outburst and grotesque death.

And as more bodies are found, her role becomes even more baffling…because each victim had intimately known Sara, a woman whose history becomes more lurid and unfathomable with each revelation. Until the case takes a sudden, strange turn—and the secrets of a woman, a killer, and a city begin to unravel…with devastating consequences….