Book 1 of The Raven Boy Saga by Kateryna Kei
The Viking king is killed and his widow is called to suggest to the council a worthy successor, able to win the raging war.
Torn between her feelings and her duty to choose the best for her people, she decides to seek the divine guidance and goes to see the rune caster.
But the message of the Gods is weird beyond belief: it says that the only person who can win the war is but a boy, the youngest of her twin sons, Hrafn.
The rune caster's predictions have never failed yet, and suddenly the queen has another problem to worry about - the second part of the prophecy promises the boy something much more dreadful than death on the battle field...