Hylas is a young Greek slave in the household of Caius Pomponius, a Roman Senator involved in political schemes. When the senator is found mysteriously murdered, the household slaves (including Hylas and his mother) fall under suspicion. Hylas escapes capture long enough to enlist the aid of a young tribune, Camillus Rufus. The desperate attempt to unravel the threads of the political intrigue carries Camillus into the very presence of Nero and brings Hylas into contact with the new secret sect of Christians.