周游神户港的游览船突然发生爆炸,犯罪者以船上的乘客作为人质,向该船的所属公司“黑泽兴产”勒索两亿日元。偶然在场的警视厅月岛署刑警系村(上川隆也),以不经意间发现的一张纸片为线索介入了这起事件。。Broke Edith murders and assumes the identity of her recently widowed, well-to-do twin sister Margaret, who had married Edith's former flame 20 years before. Can she fool the servants and the authorities and keep her new-found wealth?。