Lin Wan, an "isolated" girl who was on the verge of collapse under the pressure of the college entrance examination, was inundated with harsh criticism of being "not perfect" day after day. Transfer student Gu Yu arrived with a coldness and mystery, and accidentally broke the antidepressant bottle she had hidden. A sentence as light as a sigh, "I've eaten it too," became the first light to pierce the silence. When despair pushed Lin Wan to the edge of the rooftop and fell into the abyss, Gu Yu actually climbed up to the fifth floor with his flesh and blood body, grabbing her falling figure with his blood-stained hands. After being rescued, a photo that had been buried in Gu Yu's broken cell phone - a picture of seven-year-old Lin Wan tenderly feeding a cat under the sunset - suddenly revealed a cruel connection that spanned ten years. It turns out that the boy who hid in the dark alley corner of her childhood and watched her silently was none other than Gu Yu today. Two souls gnawed by loneliness and trauma recognize each other's glimmer of light from their distant childhood in each other's darkest moments. This is a mutual redemption of broken souls. On the edge of the abyss of despair, they finally see clearly: those tender moments that had been forgotten are the "unexpected light" that penetrates the long darkness and guides each other out of the ruins. Even if the world collapses like a dangerous building, there is always a faint light from the past that can illuminate the way back.
