In an isolated rural village, 30-year-old Xiao Hong is pressured by her mother and the matchmaker, Sister Wang, into an arranged exchange marriage. She is forced to marry Ergou, a man whose parents have both passed away, while Ergou's younger sister, Xiaohua, is expected to marry Xiao Hong's intellectually disabled older brother, Daniu. Xiaohua fiercely resists, but a signed exchange-marriage agreement makes it difficult for her to escape. After the wedding, Xiao Hong and Ergou gradually develop genuine feelings for each other, and Xiao Hong becomes pregnant. Xiaohua, however, would rather die than submit and firmly refuses the marriage, eventually running away to reunite with her lover. After Xiao Hong is forcibly taken back to her mother's home, she falls into despair and jumps off a cliff, but miraculously survives after being rescued. Sister Wang, Xiao Hong's mother, and Ergou are detained by the police for coercing the women into exchange marriages. Meanwhile, Xiaohua finally reunites with her lover and embraces a new life of freedom.