Ireland, 279 BC. A nation at war. For two boys, it will be gruelling. For Ireland . . . it will be bloody.

When the first raiding skirmishes of a foreign army are crushed and Ireland mourns her dead, one king knows their newfound peace is destined to fail. As Overking of Ailigh, Keeper of the North, he calls for the boys of his Celtic tribes to train as formidable warriors under his command.

For Aed, it begins as a fantastical quest. For Ronan, it helps him escape a cruel chieftain. Together, they must train and grow in strength and might. And when the invading army returns, a nation goes to war, united under one banner.

Meanwhile, Aed's sister begins her training as a druid, learning the spiritual ways of the earth. And when the goddess Caer speaks to her in her dreams, she knows that Ireland's future hangs in the balance.

With Aed skilled in close combat, and Ronan blessed with an archer's eye, they fight side by side, champions of the Celts. But death is close. And the tides of war are forever in flux.

The Irish Celts know one thing: if the warmongering foreigners aren't defeated, not even the druids can change the course of destiny.