Divorced for three years, Lin Mufan returns with a mysterious daughter, but is forced by her ex-husband Zhou Jiuci to keep the child and recognize her as his biological daughter through a forged paternity test. The sharp-tongued ex-husband sets up a three-month "revenge" agreement, only to retreat step by step in this game of wits. When the misunderstanding from back then is revealed, her ruthlessness turns out to be a protective wall she built for him. When pride collides with the truth, who is truly the one being guarded?