The legendary nine-tailed fox, or gumiho, Lee Yeon has lived in the city for centuries, hiding in plain sight. Though he appears human, he uses his powers to eliminate supernatural threats—and secretly searches for the reincarnation of his lost first love.

Nam Ji A, a sharp television producer who creates shows about urban legends, crosses paths with Lee Yeon while investigating her own past. Her parents vanished after a mysterious car accident years ago, and she suspects Lee Yeon may hold the key to the truth.

Meanwhile, Lee Yeon's half-brother, Lee Rang, is a charming yet dangerous figure. Half-human himself, he despises humanity and takes pleasure in deceiving people—offering to grant their wishes, only to make them pay a steep and often tragic price.