In the midsummer rain beside Baotu Spring, deliveryman Lin Shen rescued Su Tang, who was suffering from leukemia. She recorded the four seasons of Quancheng in a sketchbook, but during chemotherapy, she gradually withered like a sunflower on paper. The two weave youthful whispers between the fragrance of oil spin and the arias of Lu Opera, until Su Tang's condition deteriorates into a black thread entwining his life. When Lin Shen found a genetic sequence that perfectly matched hers in the bone marrow bank, the quantum clock tower on the top of Qingfeng Mountain was reflecting an unfinished experiment fifteen years ago. They used sketchbooks, fluorescent medicine bottles and starry sky pendants to write love letters spanning life and death in the rift of time and space - even if they turned into stardust that dissipated in the spring water, their love still echoed eternally in the surging morning light of Baotu Spring.
