A grandmother takes her six-year-old grandson to a swimming pool, and to play mahjong, she arbitrarily leaves the child alone in the children's pool. When the child looks for his grandmother, he accidentally falls into the deep water area. After the incident, the grandmother repeatedly fabricates lies, delaying the precious timing for rescue. Although the child is rescued in time, he is left with brain hypoxia damage, plunging the family into painful torment. The long rehabilitation road ahead also makes everyone see clearly the heavy price brought by luck and lies.