The Sons of Ymir -​ Book 3 in Thief of Midgard

Maskan, newly made the King of Red Midgard, has survived the battles, but is about to lose the war.

Having escaped Balic's subtler schemes, and finally having beaten the southern armies in two great battles, Maskan leads the remnants of his people to save the betrayed troops of Red Midgard against the great numbers of Balic's remaining legions, and the dark, terrifying power of the undead, the draugr. Beating the enemy in a field of battle is not enough. Balic has a mission beyond conquest of the northern lands, and that mission will spell doom for anyone opposing Goddess Hel, for Balic seeks the ultimate, hidden, forgotten weapon that no mortal can defeat; the Queen of the Draugr. Maskan's time is running out. His allies are few, and the enemy holds most of the advantages.

Victory, or even survival, seem beyond reach. 

Maskan must discover the powers of his heritage, and the ways of his ancient kin, as the newly minted king attempts to beat his great enemy in a race to deny Goddess Hel her victory, far in a northern stronghold, that seems to hold all the answers. First, he must find allies; then he must outwit the dead.