Stranded in the tumultuous era of 1938 colonial Korea, modern-day gumiho Lee Yeon finds himself trapped after a botched time-travel mission orchestrated by a masked entity. His primary objective is clear: retrieve the stolen guardian stone of the Joseon land and return to the present day to be reunited with his mortal wife, Ji-ah. However, navigating 1938 proves perilous, as Yeon collides with past versions of his closest allies and fiercest enemies, forcing him to rewrite the rules of his existence.Upon arrival, Yeon quickly reunites with a younger, deeply resentful Lee Rang, who is still nursing abandonment issues and leading a notorious band of bandits. Unaware that Yeon from the future is his older brother, 1938’s Rang clashes violently with him before eventually discovering the truth, sparking a poignant journey of
reconciliation and brotherly sacrifice that heals generational wounds. Concurrently, Yeon reconnects with former mountain gods Cheon Moo-young, once a loyal friend turned bitter enemy manipulated by dark forces, and Ryu Hong-joo, a fierce former guardian spirit and owner of a high-end club who harbors an intense, unrequited romantic obsession for Yeon.The central conflict escalates as Japanese supernatural occupiers, led by the ruthless demon Kato Ryuhei, infiltrate Korea with the insidious goal of eradicating indigenous folklore spirits and subjugating the peninsula. Kato unleashes a terrifying array of Japanese yokai, mythical assassins, and tortured hybrid monsters to destabilize the spiritual realm. Moo-young, desperate to resurrect his deceased brother, falls under Kato's manipulation, unwittingly serving as a pawn in a grand scheme to destroy the Korean mountain gods.As alliances shift, Yeon must navigate brutal martial arts showdowns,
psychological traps, and ancient curses. He forms a resistance squad alongside Hong-joo, Rang, and a mysterious masked man who turns out to be his own future self, intervening to alter tragic destinies. The dramatic climax erupts in a devastating siege against Kato’s stronghold. In a harrowing final confrontation, Yeon defeats Kato, while Moo-young redeems himself by sacrificing his life to thwart the overarching demonic plot and save Rang.With 1938 restored from total supernatural annexation and his relationships with Rang and Hong-joo profoundly mended, Yeon secures the guardian stone. Evading pursuit by ancient regional deities, he finally breaks the temporal barrier, racing across epochs through the pouring rain to fulfill his ultimate promise and reunite with Ji-ah in the present.