Kim Seon was a parasite, a thorn in the side of Jihan, the sole heir to the prestigious Choi clan. An orphan taken in, he dared to act like the eldest son, stole Jihan's father's affection, and was now poised to snatch away his intended bride. Driven to desperation, Jihan sought out a powerful shaman, begging for a deadly curse to be cast upon Seon. The shaman, however, revealed a far more sinister plan: Seon's spirit was one of excessive lust, and so he must be undone by temptation. On a night when the household was empty, Jihan's scheme was set in motion. Seon, having consumed a potent aphrodisiac, fell into a deep, drug-induced slumber. Yet, in one moment of fatal carelessness, Seon's eyes fluttered open... On a frozen February dawn, a twisted game of cat and mouse with a beast begins.