1247. Karakorum, jewel of the Mongol Empire, shivers under a terror far colder than the steppe winds. Grisly murders grip the city, each victim a twisted monument to fear, marked by an unnatural force.  Whispers name the culprit: Genghis Khan, returned not in flesh, but as a vengeful spirit, his deathbed curse unleashed upon his own bloodline for a betrayal buried with him in the heart of the steppe.

Ulan, a seasoned Khereid warrior, a man grounded in pragmatism, is summoned by the Great Khan. Haunted by whispers of his own ancestry, Ulan is tasked with silencing the growing panic and unraveling the truth.  His investigation plunges him into a world of contorted bodies and whispered secrets, where the Mongol elite, cloaked in silk and fear, conceal ambitions as treacherous as the empire's internal struggles.

Shamans speak of disturbed spirits and forgotten gods.  Ancient texts reveal the Khökh Mönkh, the "Blue Wolves," a shadowy sect led by the enigmatic Bridget Mosley, who seeks to wield the curse as a weapon to seize control. But even they cannot contain the escalating horror.

Ulan's pursuit of the truth leads him beyond Karakorum's walls, into the vast steppe, where he encounters Naraa, a young shamaness whose wisdom defies her age.  Together, they uncover a hidden truth, a secret buried by Genghis Khan himself, a secret that could shatter the empire's foundations.  He learns the curse is not mere vengeance, but something far more profound, intertwined with the very soul of the Mongol Empire.

As the line between the living and the spectral blurs, Ulan must confront not just a vengeful spirit, but the dark heart of his ancestors and the empire they forged.  He must embrace a spiritual world he has long denied, forge uneasy alliances with a cunning Rus’ merchant named Elina Petrova, and face the shadows of his own past, a past inextricably linked to the Khan’s wrath.

In the heart of Karakorum, amidst the spectral hordes unleashed by the Blue Wolves, Ulan faces his final test. He must decipher the Khan's true intent – a truth far more terrifying, and far more crucial, than mere revenge. For the Khan’s curse was not a curse at all, but a desperate warning against a forgotten evil that now threatens to consume everything. The fate of the Mongol Empire, and Ulan’s very soul, hang in the balance.