Etruscans

In the early days of the Roman Empire, the noble Etruscan civilization in Italy is waning, Vesi, a young Etruscan noblewoman, is violated by a renegade supernatural being. Outcast then from Etruria, Vesi bears Horatrim, a child who carries inexplicable knowledge and grows to manhood in only six years. But a savage Roman attack leaves Vesi unresponsive and Horatrim homeless and vulnerable, and he travels to Rome where his talents confound powerful businessman Propertius, who arranges to adopt Horatrim as a son, changing his name to Horatius.

And all the while his demon father is seeking him to kill him, for Horatius is a conduit through which the demon might be found and destroyed.