Lu and Feng are a devoted couple forced to separate when Lu is arrested and sent to a labor camp as a political prisoner during the Cultural Revolution. He finally returns home only to find that his beloved wife no longer remembers him.

Before the Seavers leave for a family vacation to San Francisco, they drop off their pets -- Chance, an adventurous American bulldog; Shadow, a wise golden retriever; and Sassy, a cautious cat -- at a friend's ranch. But when the animals start to worry that they've been left for good, the three embark together on a treacherous and thrilling journey to find their way back home through the California wilderness.

When the pets accidentally get separated from their vacationing owners, Chance, Shadow, and Sassy navigate the mean streets of San Francisco, trying to find their home across the Golden Gate Bridge. But the road is blocked by a series of hazards, both man and beast.