"Princess Elena of Astria marries Kane, the Northern Wolf King she has known since childhood, in a desperate bid to end the north-south war. She once swallowed heart-devouring bugs in Black Pine Forest, trading her own lifespan to save Kane, yet her friend Vivian steals credit for the rescue. Kane knows Elena loves him, but turns their marriage into a weapon of revenge: on their wedding day, he hides weapons among the gifts, coordinates with traitors inside the capital, and launches a coup that kills Elena's parents and elder brother. Months later, he also destroys their unborn child.
After ascending the throne, Kane marries Vivian as his queen. He imprisons Elena in the North Tower and uses her family's remains to force her to stay alive and endure his punishment. As the curse draws near to claiming Elena's life, she is humiliated and scalded at the queen's birthday banquet, forced to defend her unborn child's unmarked grave, and later mauled by a wolf beast. Kane still dismisses her agony as a ploy for his affection. Only when she slips into a near-death coma before him, her breath barely detectable, does he summon the full royal physician corps to save her.
A wilderness healer uncovers the truth of Black Pine Forest. He also reveals that the tonics Kane has forced her to take for years have been speeding up the heart-devouring bugs' reproduction. Kane takes the curse onto himself with his own blood and briefly revives Elena. He punishes Vivian, moves their child's remains into the royal mausoleum, and restores Elena's former chambers and status—but he cannot win back her love.
Before her death, Elena learns her elder brother's son is alive. Kane opens the capital to the young heir, then abdicates after Elena dies and returns the crown to House Aldrich. He spends the rest of his life cursed and alone beside Elena and their child's graves, unforgiven."