Chinese Title: 陀槍師姐IV
Cast: Ada Choi, Frankie Lam, Yoyo Mung, Joyce Tang, Bobby Au Yeung, Marco Ngai, Evergreen Mak, Ha Yu, Mimi Chu, Maggie Wong, Raymond Cho, Ha Ping, Rosanne Lui
Synopsis: This story continues from Armed Reaction III by following our 4 main characters, Chen Siu Sang, Wai Ying Zi, Chen Sam Yuen, and Ching Fung in their roles as enforcers of justice and emotionally involved men and women. Wai Ying Zhi's performance at work has given her confidence and her relationship with Siu Sang is now stable. However, a gap starts to form in their relationship as Siu Sung is very eager to get a married and start a family while Ying Zhi wants to focus on her career and get promoted to an inspector ranking first. On the other hand, Chen Sam Yuen is pregnant and has been temporarily transferred to the Traffic Formation wing while waiting for the upcoming birth. After experiencing all of these hardships, Sam Yuen has developed a new way of thinking and philosophy towards life. The once extremely career driven Sam Yuen's new focus is now on the family, her husband, and her daughter. She is now truly a little housewife. Her husband Ching Fung's career is reaching new heights as he is promoted to Chief Inspector. The criminal investigation part of the series involves Fung's Special Investigation Unit gaining evidence against the triad group Hung Ying.