Having found the first of Cassio's four assassins, archeologist Ornella Grazzi attempts to solve the mystery of the second. And as she pieces together tantalizing fragments of historical evidence, she learns of Cassio's forbidden love for Oasis, virgin priestess of Apis. But why has Cassio traveled to Antioch? Why is he bent on discovering the secrets of its citizens? In the present day, a break-in at the university lab leaves a technician dead and Ornella's findings missing. Could this be the work of the enigmatic Lucas Tanhauser, the older gentleman who has insinuated himself into Ornella's life?