Eunice Torrence (June Elvidge) has wed the elderly Geoffrey Farrow (Joe Herbert) only because her mother (Isabelle Berwin) wanted her to marry money. But Farrow is a rotten character and Eunice, who really loves Don Chadwick (John Bowers), immediately regrets her decision.

In 64 A.D., Marcus Superbus is Prefect of Rome. When the Emperor Nero decides to renew persecution of the Christians, Marcus opposes him, fearing for the safety of Mercia, the Christian woman whom he loves. Through the machinations of the Empress Poppaea and other women at court, Tigellinus, Nero's agent in the war against the Christians, convinces Nero to have Mercia arrested. Marcus appeals to the emperor for mercy, but is told that she can be saved only by renouncing Christianity. Waiting to enter the arena to be killed, Mercia steadfastly refuses to reject her religion, despite Marcus' pleas. Finally, Marcus is converted by her and they enter the arena to face death together.