A Greek slave is forced into the gladiatorial service when he defends an elderly merchant from the attack of a sadistic centurion. But he also has the hallowed robe of Christ - a fact which makes him the target of Emperor Caligula and the treacherous Messalina, because they believe it has special powers. But the reluctant gladiator does not intend to give it up to them. Historical drama, starring Victor Mature, Susan Hayward, Michael Rennie and Debra Paget.

The story picks up at the point where "The Robe" ends, following the martyrdom of Diana and Marcellus. Christ's robe is conveyed to Peter for safe-keeping, but the emperor Caligula wants it back to benefit from its powers. Marcellus' former slave Demetrius seeks to prevent this, and catches the eye of Messalina, wife to Caligula's uncle Claudius. Messalina tempts Demetrius, he winds up fighting in the arena, and wavers in his faith.