Because of an accident, a man who possesses godly skills at opening locks catches the eye of a female detective and they go on to solve cases together. Mu Xia (Jin Shijia) is a talented locksmith. While dealing with a strange murder case within a locked room, Qin Zuoman (Chuo Ni) inadvertently discovers that Mu Xia is the new security consultant hired by the police academy. As more locked room cases arise, the simple-minded Qin Zuoman, the monotonous Mu Xia and celebrity cop Tan You (Chen Yilong) join hands to form an investigative team that seeks to uncover the truth through every door.—ChineseDrama.Info