In that summer when the fragrance of gardenias and library books filled the air, Lin Shen, the aloof academic god of the Department of Physics, lived like a precisely calculated parabola, rigorous and regular, not allowing for any unexpected variables. Until that day, a "variable" named Su Qianqian broke into his world recklessly. She was like a breath of cool wind carrying mints, disrupting the tranquility of the pages of his book, and leaving a forgotten old-fashioned film camera in his heart. The camera captured a world full of life that he had never seen before. In order to return this camera, two parallel lines that did not intersect began to have their first intersection. He chased her figure with his lens, and she lit up his loneliness with her brightness. This is a story about secret love, growth and two-way running. When the cicadas chirped in the summer night again, my heart moved a little, and I couldn't hide it anymore.