
Much to his surprise, Marcellus returns her feelings and asks her to wait for him. Before Marcellus' ship sails, Diana comes to pledge her love and state that she will intercede on his behalf with Tiberius. Marcellus shrugs off his concerns, as well as those of his mother Cornelia and sister Lucia, but Caligula's power is soon felt when Marcellus receives a notice that he is to leave immediately for the dangerous garrison at Jerusalem, in Palestine.

When he returns home, Marcellus is upbraided by his father, Senator Gallio, who is trying to reinstate the Republic in Rome and worries that Marcellus' feud with Caligula is undermining his efforts. After Caligula storms off, Marcellus has Demetrius' chains removed and orders him to report to his steward, Marcipor. Infuriated, Marcellus then outbids Caligula for Demetrius. When Caligula arrives, he is angered to see Marcellus, and slyly expresses his ire by having his henchman, Tribune Quintus, outbid Marcellus for the twins. Marcellus is less amused by Tiberius' intention to marry Diana to his nephew and heir, the corrupt Caligula, whom Marcellus detests. Diana, now a self-assured young woman, reminds Marcellus of his long-ago promise to marry her, and Marcellus jests about honoring his pledge.


While waiting for the market to open, the womanizing, cynical Marcellus is delighted to be approached by Diana, a former childhood playmate who, since being orphaned, has been Tiberius' ward. In the market, Marcellus witnesses the attempted escape of an educated Greek, Demetrius, and helps the slavemaster capture him. In ancient Rome, during the eighteenth year of the reign of Tiberius, military tribune Marcellus Gallio goes to the slave market to purchase a pair of Macedonian twins.
