After losing his two-year-old son, Lei (Andy Lau) begins a fourteen-year-long quest in search of his missing child. Hanging off the side of his motorcycle is his most valued token, the last picture he ever took of his son, which has been circulating on the microblogging community.
On the road, he makes a stop at a repair shop where he comes across a young repairman, Zeng (Jing Boran), who was also kidnapped at the age of four. Robbed of the life he was meant to live, Zeng can only vaguely remember snippets of home – a chain-link bridge, bamboo trees, and his mother’s long braids.
Impassioned, Lei posts Zeng’s story and information online. Agreeing to help each other’s cause, Lei accompanies Zeng to Chongqing to try to find his home, developing a fatherly relationship along the way.