Battle-scarred veterans of the Roman army Tribune Cato and Centurion Macro return to Rome. Thanks to the failure of their recent campaign on the eastern frontier they face a hostile reception at the imperial court.

Their reputations and future are at stake. When Emperor Nero's infatuation with his mistress is exploited by political enemies, he reluctantly banishes her into exile. Cato, isolated and unwelcome in Rome, is forced to escort her to Sardinia.

Arriving on the restless, simmering island with a small cadre of officers, Cato faces peril on three fronts: a fractured command, a deadly plague spreading across the province...and a violent insurgency threatening to tip the province into blood-stained chaos.