A year has passed since Do Do-hee, the sharp-tongued chaebol heiress, and Jeong Gu-won, the centuries-old demon, narrowly escaped the clutches of fate in Season 1. Their fragile happiness is shattered when a series of supernatural anomalies erupt across Seoul—portals tearing open in the sky, shadows moving without light, and mortals waking up with fragments of demonic power. Gu-won realizes that the pact that restored his abilities at the end of Season 1 came at a hidden cost: the barrier between the demon realm and the human world is weakening, and someone—something—is forcing its way through. Worse, the disturbances are tied to a figure from Gu-won’s forgotten past, a rival demon lord known only as "The Hollow," who seeks to consume human souls on a scale not seen for centuries.
Do-hee refuses to stand by while Gu-won faces this threat alone. Balancing her corporate battles against ruthless board members with her growing role in the supernatural world, she becomes a target for those who see her as Gu-won’s mortal weakness. As they investigate, the couple learns of a prophecy buried in ancient demon scripture—one that speaks of a human who can either save or destroy both realms. The prophecy’s details are maddeningly vague, but one thing is clear: the human in question is Do-hee herself. This revelation drives a wedge between them, as Gu-won struggles with the fear that protecting her may require sacrificing the very world they’re trying to save.
The season’s middle arc deepens the mythology of the demon realm, taking Gu-won and Do-hee into spectral markets, haunted ruins, and cursed temples to gather the artifacts needed to seal The Hollow’s power. Along the way, they are forced into uneasy alliances: a disgraced exorcist with a vendetta, a rival conglomerate heir with his own demonic patron, and even a mischievous fox spirit who trades secrets for chaos. Each artifact comes at a price—painful choices, fractured trust, and escalating danger as The Hollow begins to manifest physically, feeding on fear and greed. The personal stakes rise when Do-hee starts exhibiting signs of demonic influence, her eyes flashing with otherworldly fire and her words sometimes not her own. Gu-won is torn between believing she can resist the corruption and preparing for the unthinkable.
In a heart-pounding finale, The Hollow unleashes a cataclysm during Do-hee’s company’s centennial gala, merging the human and demon realms in a storm of fire and shadow. Gu-won and Do-hee, fighting side by side, manage to trap The Hollow in a collapsing dimensional rift—but only by binding part of Do-hee’s soul to Gu-won’s for eternity. The season ends on an emotional knife’s edge: they’ve saved the world for now, but Do-hee is no longer fully human, and her future is uncertain. The final scene shows her looking out over the city at dawn, the faint glow of demon fire flickering in her eyes, while Gu-won watches from the shadows with a mixture of love, pride, and fear. A whispered promise hangs between them: “Whatever you become, I’ll be there.”
