She bears the legacy of two great warriors—a Viking father, the most feared warrior Hilda has ever known, and a Scottish mother, the famed warrior-woman of the Highlands. Hilda Aland Callan is hot-blooded and fearless, seeking glory in battle—until her reckless ambition leads to her mother's tragic death.

Consumed by guilt and desperate for redemption, Hilda embarks on a perilous quest to find the mysterious attackers who shattered her world. Her journey leads her to a band of warriors led by Maxwell Black—a giant who wields a sword the size of an ordinary man. Feared by all and nicknamed Thor, the Norse God of Thunder, he seems more monster than man.

When Hilda confronts Maxwell, ready to face certain death, she discovers he is not her enemy. Instead, he's a rogue mercenary with his own haunted past, seeking vengeance for a loss he blames himself for. Striking an uneasy alliance, Hilda and Maxwell set out together, but even her own warriors fear him, knowing that if he turned against them, it would take half a dozen men to bring him down.

As they close in on their enemies, Maxwell suddenly loses his will to fight, laying down his arms. Betrayed and captured, Hilda finds herself locked away, with time running out. To escape and achieve her revenge, she must unlock the secrets of Maxwell's tormented heart before they both meet a terrible fate...