First-century Rome is a perilous city as Nero stalks the political circles and huddled groups of believers. To be safe, Christians must remain invisible. Gallus Sergius Vitas is the only man within Nero's trusted circle willing to do what it takes to keep the empire together. He struggles to lessen Nero's monstrosities against the people of Rome - especially the Christians. But as three Greek letters are scrawled as graffiti throughout the city, Nero's anger grows.