Profiling two families living in rural Cambodia, A River Changes Course is a delicate documentary about a way of life that's slowly disappearing, yet gives way to nothing new. Director Kalyanee Mam eschews stats and interviews with experts and, except for one pivotal moment at the end of the film, removes herself from the documentary altogether. She lets her subjects and her visuals do all the talking, and through them paints a woeful portrait of two families for whom fishing and rice farming, respectively, no longer provide enough money or food to subsist on. The fish are no longer as plenty in the river, while larger companies and loggers clearing the forests are slowly taking farmland away. "All the young people have gone away by the truckload," says Sav Samourn, the head of the rice-farming family, in reference to the exodus of villagers heading to the capital, Phnom Penh, for jobs in the garment factories. The fisherman's son also leaves, in his case to plant cassava for the Chinese in western Cambodia. Neither finds the satisfaction they hoped for though. The ideal futures they envision in front of the camera remain out of reach, pointing to perhaps the most distressing aspect of this deeply moving doc: that for all the changes the younger generation is facing, a shift away from subsistence living isn't one of them.