At thirty-eight degrees in midsummer, the habitually frugal mother stubbornly refuses to turn on the air conditioning. Her beloved dog suffers heatstroke and is sent to the medical center, causing the conflicts between daughter-in-law Li Xin and the mother to continually escalate. Son Wang Cheng uncovers a secret sealed for twenty years: back in their impoverished years, their younger daughter's death was actually due to being given away for adoption. The long-lost younger sister returns in search of her family, and the family lets go of their fixations, unties their emotional knots, and finally enjoys a reunion once again.