舞女阿红遇害，周玉蝶因现场遗留其首饰成为嫌疑人。粉丝关仁为替其洗脱嫌疑展开追查，却遭遇证人接连身亡，更牵扯出周保及其神秘未婚妻等复杂关系。随后，张生离奇中刀身亡，其私生子身份成谜；而张夫人抚养多年的"养子"，实为外室所生。银行王老板死于密室，看似自杀实为他杀。李氏千金陈尸衣柜，伴随杀人布偶诡异现身，牵出与机械高手之女的旧日恩怨。又一名带有梅花印记的女子遇害，而此前主要嫌犯竟在狱中自尽。直至周玉蝶表演时被拍到腿上的梅花印记，一段辛酸往事终被揭开。幕后真凶究竟是谁？详情
祝氏和邓氏的家族生意以儿女的婚姻为筹码，祝笙和邓邵涵两人由此开始了复杂的感情生活。
本剧围绕15年前震惊全日本、却突然销声匿迹的连环杀人犯“蝙蝠”展开的作品。此人神出鬼没，受害者之间毫无关联，且无论运用何种犯罪侧写手法，都无法确定其年龄、性别甚至体格。在所有作案现场，遗体旁都撒有“黑色花瓣”，但凶手的真实身份和作案动机始终不明，案件最终成为悬案。临床心理师安堂枫是“蝙蝠”杀害其父母的受害者遗属之一，她本人也曾被囚禁在黑暗中长达半年。另一方面，她无血缘关系的弟弟奥泽雪路的父亲也被“蝙蝠”所杀，他怀着将凶手绳之以法的强烈愿望，成为一名刑警，奔赴侦查最前线。就在此时，时隔15年，“蝙蝠”的杀人案再次发生。
As Leo's replacement Thomas Chamberlain arrives Nikki investigates the murders of Rachel Freedman, shot in the head, and her little autistic son Nathan, who was poisoned. Nikki rejects policewoman Anne Burchett's theory that Rachel killed them both but is perturbed when an impostor, claiming to be Rachel's sister, visits the morgue. At the same time the disfigured corpse of Eva Liron is discovered, killed with the same poison as Nathan. She had been the nanny to French hot shot footballer Isaac Dreyfus and was planning to blackmail him over a sex tape of them both. Jewish Isaac is a controversial figure due to his anti-Muslim sentiments but he denies ant part in the murders. Then another victim, Isaac's agent Mousa, is discovered dead.
