College student Li Chenyue accidentally discovers a distress signal hidden in a candy wrapper by his "silly" mother. Through his father's diary, he uncovers a conspiracy from nineteen years ago: his mother was actually abducted and used to pay off debts, and was coveted by the bully Sun Zhiming. His mother's words "be " back then actually came true, scaring away the villain, and since then she has pretended to be silly to save her life. After discovering the secret of the cellar in the backyard, Li Chenyue is determined to find out the truth and vows to break the imprisonment and rescue his mother from the abyss.