A former gladiator promoted to tribune, he is recruited by Governor Valerius to halt barbarian raids. He uncovers Roman-made weapons used by the enemy, suspects Consul Caius of treason, and infiltrates the border regions. After discovering Caius ordered his father's murder and framing him for Manlio's death, he wages a personal vendetta, ultimately exposing the consul's treachery with Valerius's aid.