Cheng Li is staying at a guesthouse in rural western China. He's alone and feeling isolated. But he's discovered an old photograph of his great-grandmother, and he starts talking to her. He tells her about his work, and why he's disillusioned. In response she reveals to him how she originally moved to Tianjin, their family's home-town, and why she loves the city. Thereafter Cheng Li is drawn into a remarkable journey involving sacred polarities, steam locomotives, and a water dragon. He is inspired to ... have some oolong tea for starters.