In the autumn of 573 AD, the civil war that divides the Celtic nations in the post Romano- Britiain ends at the battle of Arthuet. The Celtic amies disband and the warriors return to their homes, but the losses to the combined Celtic forces are so great that the immigrants from Germania - the Angles who settled along the North Sea, boldly send raiding parties into the Celtic homelands.

In early 1860s New York, Irish immigrant Amsterdam Vallon is released from prison and returns to the Five Points, seeking revenge against his father's killer, William Cutting, a powerful anti-immigrant gang leader. He knows that revenge can only be attained by infiltrating Cutting's inner circle. Vallon's journey becomes a fight for personal survival and to find a place for the Irish people.