A white stag and a dagger transform the life of Prosper, a Welsh chieftan's son. With Conn, his bodyservant, he leaves his isolated valley and joins the war band of King Mynyddog the Golden as a shieldbearer. For the Saxons have returned to threaten the northern tribes of Britain, and the Shining Company—a brotherhood of three hundred chosen warriors—must make a desperate attempt to repel invaders.

And with the Company travels the minstrel Aneirin, who will keep their names and their glory alive forever more.