Su Jin has been able to see other people's nightmares in the mirror since she was a child. She should have escaped from the world, but because of an old family letter, she embarked on a journey to find the "Mirrorless Key". It is the legendary lost artifact that can separate reality and illusion. No one in the world has seen its true appearance, but it is secretly pulling the broken destiny. Under the shadow of the city, the souls of the missing are silently calling for help, and the silver light of the ancient mirror hall shines with an indescribable language. Su Jin wanders in the gap between reality and fantasy. Every time she solves a puzzle, the fog of her life becomes thicker. She gradually discovers that the "Mirrorless Key" is not an ordinary thing, but a secret shackles for every soul. Su Jin longs for redemption, but in the entanglement of supernatural events, she gradually cannot tell whether she is a traveler pursuing the truth or a ghost selected by the key. People's hearts, fate, reality and reality are intertwined. Can Su Jin uncover the real curse behind the lost artifact at the end of the mirror world?
