重案组陈岳（古天乐 饰）接到了一起情况十分恶劣的命案，受害者高达五人之多，而其中唯一的幸存者陷入了昏迷之中，不知何日能够醒来。追随着少之又少的线索，陈岳找到了金毛盈（林雅诗 饰），从她口中得知了一个神秘的教会。

　　陈岳派出金毛盈来到教会卧底，然而随后便失去了她的音信，无奈之下，陈岳只能只身深入虎穴，见到了教主皇唯一（连凯 饰）。让陈岳感到震惊的是，皇唯一居然知道自己不为人知的悲惨身世，而自己的母亲亦和邪教有所瓜葛。为了打败皇唯一，陈岳找到了如今身陷囹圄的教主林越天（郑浩南 饰），林越天传授了陈岳打败皇唯一的秘籍，一场血战即将拉开序幕。

During an investigation into a mass murder with links to a doomsday cult, Officer Chan (Louis Koo) reluctantly enlists police occult expert Officer Chiu (Anthony Wong Chau-Sang) to help him solve the case. But during their investigation of the cult and its charismatic leader The Pope (Hoi Lin), they realize the killings may be related to a previous serial murder case, their own pasts, and the psychotic hypnotists in charge of it all may be preaching some truth...