Set during the turbulent 1940s and 1950s, the film portrays a time when love was fragile and hard-won—when a simple token of affection, a love song, or a promise could linger in the hearts of separated lovers for years.

Fang Daolong (played by Sean Lau), a policeman with a complicated background, meets the legendary and resilient Chen Yuerong (played by Tang Wei). Their romance unfolds across three cities: they fall in love in Anhui, are separated in Shanghai, yet continue to hold onto a shared promise—to reunite one day in Hong Kong.

One night, Daolong waits anxiously along the shore of Hong Kong Island for the small boat carrying Yuerong to arrive. Unexpectedly, disaster strikes during the journey, leaving uncertainty over whether Yuerong can safely reach Hong Kong and begin a new life with him.

Inspired by a true story, the film tells a deeply emotional love story from an earlier generation, capturing themes of separation, endurance, migration, and hope amid the upheavals of modern Chinese history.