Amy angrily confronts Shirley, revealing she only befriended her with ulterior motives and admits to drugging Shirley's drink. Shirley, distressed, refuses an offer to call the police, seeking comfort elsewhere instead. Later, Shirley vents to a friend about her father's quick remarriage to a widow, bitterly resenting her new stepfamily. At her coming-of-age party, Shirley is forced to greet her new aunt, Daisy, and her stepsister, Sofia. The episode's key turn arrives when Shirley locks eyes with Sofia and realizes with shock that her new stepsister is the same woman she had an intimate encounter with months earlier.