A college student, Xiao Liang, rents a second-floor apartment facing the street. Every day, the female owner of the milk tea shop downstairs delivers homemade sour plum juice. Noticing an abnormal smell, Xiao Liang insists on not drinking a single sip and pours it all out, subsequently fishing out a small bottle containing her own photo and hair from the sewer. Police investigations reveal that behind the owner lies a scam syndicate using luck-altering as a front—the sour plum juice is laced with hypnotic drugs and paired with talisman charms to control young people living alone, taking advantage of their muddled state to extract loans. With her vigilance, Xiao Liang assists the police in unearthing the mastermind and rescuing multiple victims.