Based on the novel "When the light is out" by Ngô Tất Tố. Under the cruel domination of the French Indochina, a woman has to sell her daughter and four dogs to a rich family in the village to save her husband from being tortured when they can't pay their taxes.
The main character in the film is a real person in history - the hero of the Vietnamese people's army, Cu Chinh Lan, set in the middle of the resistance war against the French (circa 1951) on the battlefield in North Vietnam.