Moon Sangyeol, a pharmacist running a small apothecary on the outskirts of Hanyang (old name of Seoul City), is asked to procure the “Snake’s Horn,” a rare ingredient said to make infertile women conceive, in exchange for a massive sum of money. Having long been worn down by poverty and dreaming of striking it rich overnight, Sangyeol eagerly scours Yeongsan Mountain high and low. At last, he discovers a snake’s den and rejoices... but only for a moment. A chilling presence creeps up behind him.

*“How vulgar. Do you desire to bear offspring that badly?”*

The owner of the shadow is Lee Hwan, a hornless serpent who despises humans. Startled, Sangyeol tries to smooth things over somehow, but before he can even make an excuse, he’s slammed to the ground.

*“You’ll only get one chance, so you’d better make the most of it.”*

Perched over him, Hwan’s red eyes glint eerily.