A woman named Charlotte has lived in a quiet countryside since she was a child. Her childhood should have been carefree, however, one summer night, a sudden midnight flute sound, but quietly changed the trajectory of her life. The sound of the flute was poignant and sorrowful, as if it had traveled through time and space, telling of a forgotten past. Charlotte is deeply attracted by the sound of the flute, but when she is looking for its source, she accidentally witnesses a horrifying scene: the figure of a teenager, in the midst of a blossoming bush of poisonous flowers, casts a pair of deep and sorrowful eyes at her. Immediately afterward, a sudden thunderstorm washes it all away, leaving only the sound of the flute echoing in the night sky for a long time. Waking up the next day, Ikatsui chose to remain silent about last night's experience. It was as if she had never stepped out of her room, burying that memory deep in her heart. However, the sound of the flute and the teenager's eyes that night were like a brand, etched into the depths of her soul, becoming a nightmare she could not get rid of. As the years passed, Charlotte grew from an innocent girl to a gentle and touching woman. However, no matter how the years change, the memory of that summer night always follows her, and whenever it is late at night, it will quietly emerge, pulling her back to that afternoon of thunderstorms. She had dreamed countless times of that poisonous bush, that wall that seemed to separate life from death, and those eyes that she could never forget. Charlotte knew deep down that this memory was not just her personal secret, but also an unsolved mystery, a major secret that concerned her fate. As a result, she had never revealed this experience to anyone, including her closest father. The wall, to her, was like a tomb, neither to be approached nor to be touched, but only to be looked at from afar, her heart filled with endless fear and curiosity. However, fate does not seem to intend to let this secret lie dormant forever. As Charlotte grows up, a series of bizarre events begin to quietly occur around her. Whenever it was late at night, the ancient flute would sound on its own. The melodious and mournful sound of the flute seemed to be telling an ancient and tragic story. Charlotte realized that whenever the flute sounded, an inexplicable power would surge in her heart, driving her to explore the secrets behind that flute.