Roman Egypt under Commodus. Marcus and Scaurus are sent to Alexandria after the garrison at a remote southern outpost is destroyed and the Red Sea trade route is threatened. The mission takes them from the wealthy capital of Aegyptus towards the frontier with Kush.
The investigation becomes a military expedition into desert, river and trade networks that matter to the empire’s wealth. Marcus must discover who is attacking Rome’s southern reach while surviving the ambitions of officials who treat the province as both prize and weapon.