Livia, wife of Emperor Augustus plots against his daughter Julia and manages to convince him to bring her son Tiberius back from exile.

Germanicus has been murdered in Antioch and his wife Agrippina is convinced Tiberius ordered the killing. Livia has discovered that Caligula helped to poison his father. While Tiberius's perversions have become notorious, his right-hand man Sejanus, commander of the Praetorian Guard, gathers more power for himself, including a marriage alliance with Claudius.