A film of quiet beauty and honor, “Promise Through Lifetime” celebrates the heroic efforts of the teachers at a primary school in a Chinese mountain village. In the film, which is based on a true story, three generations of educators work in tandem to support the poor students of the area. Sacrificing their own opportunities, the teachers make a promise to live on the mountain for their entire lifetimes, ensuring that the village’s children receive the education necessary to make a better life elsewhere.