Like his father before him, Donn is born to the now mythical role of the Lord of the Mountain, a remote community in rural Ireland, unmarked by the passage of time. But Donn longs for a wider kingdom. He deserts his bride, roams the world, fights in wars, is footloose - yet finds that he is homesick.

Sixteen years later he returns to take up the threads of his old life, to learn to love his afflicted daughter, and to bring progress to the neglected green valley. Light comes, water flows, the land prospers. Then, on a night of innocent festivity, a monstrous crime is perpetrated.

His kingdom violated, Donn dedicates himself to a terrible revenge that can only destroy the avenger as well as the hunted