Fifteen years after Rome's invasion of Britannia, centurion Marco is back. The island is settled now, bustling with commerce. Macro's goal is to help run his mother's Londinium inn, and exploit his land grant. He's prepared for the dismal weather and the barbaric ways of the people. But far worse dangers threaten all his plans.

A gang led by an ex-legionary rules the city, demanding protection money and terrorising those who won't pay up. The Roman official in charge has turned a blind eye. Macro has to act. He needs the back-up of the finest soldier he knows: Prefect Cato. But Cato is in distant Rome. Or is he?

As the streets run red with blood, the army's heroes face an enemy as merciless and cunning as any barbarian tribe. The honour of Rome is in their hands ...