The Emergency Unit (EU) is the first responder of the police force capable of handling any emergency situations by dispatching uniformed officers into the field. Newly appointed sergeant [Ling Sun Fung/凌晨風(Tracy Chu/朱千雪)] understands that she can’t afford to make any mistakes on the job and often urges her fellow team members to race against time.
One particular day, Ling Sun Fung gets involved in an exchange of fire with a group of criminals while she’s on patrol with her team. During the exchange, Ling Sun Fung is repeatedly hindered by the chief of the walled village [Kwan Ding Ming/關鼎名(Vincent Wong/王浩信)]. She ends up letting the criminals escape and also witnesses her own father getting killed by stray bullets. Out of nowhere, a supernatural event takes place. (ahmike.com) Ling Sun Fung is able to travel back in time from April 1st to April 3rd over and over again. She takes advantage of the strange phenomenon to save her father without realizing the residual effects of altering the timeline.
Kwan Ding Ming somehow learns about the secret of Ling Sun Fung. He collaborates with her to investigate corruption in the force and become friends with her. Yet, Kwan Ding Ming has been concealing his real identity all along. At the same time, those close to Ling Sun Fung such as her colleague/boyfriend [Kwok Shang Ching/郭尚正(Benjamin Yuen/袁偉豪)], the unsociable emergency unit captain [Chan King Wai/陳勁威(Pal Sinn/單立文)], and her good friend/journalist [Lee Zi Ting/李姿婷(Zoie Tam/譚凱琪)] are all dragged into this paranormal occurrence and experience something beyond their control…..