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.