Imperial agent Cassius Corbulo is about to go rogue. His bodyguard, Indavara, has been kidnapped and has seemingly vanished off the face of the earth. Having spent weeks trying to discover his fate, Cassius's time is up: his superiors want him to return to duty.
But when an old ally's daughter is enslaved, he feels obliged to repay a long standing debt. Refusing the offer of a prestigious post, Cassius - and his Christian servant Simo - join nomadic chieftain Kabir and a trio of warriors, determined to rescue the missing girl. Now operating outside the law, the unlikely band journey across the perilous plague-ridden hinterland of Asia Minor, hunting the slavers. But these are no common criminals, and Cassius finds himself up against ruthless, cunning men with powerful friends and a lot to lose.