The Leopard Sword (Empire, #4)

The Empire series begins a new era—Marcus has fled from Britannia, but the emperor's henchmen are still on his trail

Britannia has been subdued—and the murderous Roman agents who nearly captured Marcus Valerius Aquila, alias Corvus, have been defeated by his friends. But in order to protect those very friends from the wrath of the emperor, Marcus must leave the province which has been giving him shelter. He travels to the Tungrian auxiliary legion's headquarters in northern Gaul where a different kind of war and very different dangers await him.