AD 51.

For nearly a decade, the Roman Empire has fought to assert its hold over Britannia. But relentless opposition from native tribes led by the fanatical King Caratacus threatens to destroy everything. Prefect Cato and Centurion Macro are dispatched from Rome to aid the campaign.

Placed in command of an outpost in the remote western mountains, they face a challenge even more deadly than the unremitting attacks of barbarian forces. For they must wrench control of the fort from Centurion Quertus, a man who wages a savage personal war and inspires a loyalty in his men above their bond with Rome. With dangerous enemies on both sides, Cato and Macro face the fight of their lives to bring peace to the most perilous frontier in Europe.