Mu Xia is a talented locksmith. While dealing with a strange murder case within a locked room, Qin Zuo Man 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 Zuo Man, the monotonous Mu Xia and celebrity cop Tan You join hands to form an investigative team that seeks to uncover the truth through every door.
Mu Xia
Qin Zuoman
Tan You
Shang Weiwei
Li Yanjun
Dr. Wu Xiaodong
Yang Xue
Wang Ming