While on patrol duty, EU sergeant Ling Sun-fung and her team are called to assist a criminal chase. A gun battle erupts and Sun-fung loses her father, who dies from a stray bullet to the head. Sun-fung continues the pursuit, but a strange natural phenomena suddenly turns her away, taking her back to April 1—three days prior to the incident. Realising that she has traveled back in time, she uses this opportunity to save her father's life. Village chief "Ditch", an informant for the ICAC, discovers Sun-fung's special ability and teams up with her to investigate a corrupted cop. Unfortunately, their persistent disruption to the timeline causes severe butterfly effects, with unsettling consequences. Sun-fung learns that her power to change the past does not make her able to control the future.
Cast and characters
Vincent Wong as Hugo Kwan Ding-ming — also known as Ditch, a wealthy village chief. He works as an informant for the ICAC and is aware of Sun-fung's time-travelling ability.
Tracy Chu as WSGT Ling Sun-Fung — a sergeant in HKP's Emergency Unit. She discovers an electricity pylon where a time portal would open at 00:00:00 on April 4, allowing her to travel back in time to the same day, April 1.
Benjamin Yuen as SGT Kwok Sheung-ching — a sergeant in HKP's Emergency Unit, and Sun-fung's boyfriend.
Christine Kuo as Joyce Cheung — Ditch's ex-girlfriend.
Rebecca Zhu as Fung Chi-ching — Wai's wife.
Pal Sinn as PC Chan King-wai — known as Wai Ye, the van leader of Sun-fung's EU team.
Moon Lau as Ho Siu-mei — a model and Sun-fung's friend. She is the rich man Ho Chin-cheung's younger sister.
Vincent Lam as Tom Ho Chin-cheung — Siu-mei's older brother.
Law Lok-lam as Ling Hoi — Sun-Fung and Sun-Gwong's father. Ching-Yin's husband.
:zh-yue:呂珊|Rosanne Lui as Siu Ching-yin — Sun-fung and Sun-gwong's mother. Ling Hoi's wife.
:zh-yue:李晉強|Clayton Li as Ling Sun-gwong — Ching-yin and Ling Hoi's son and Sun-fung's younger brother. He has a pet beetle named Bobby.
Development and production
Myolie Wu was originally offered the lead role to play Ling Sun-fung, but declined as she was planning not to renew her contract with TVB. After Wu declined the drama Kate Tsui was named as a possible replacement, but since Tsui also decided not to renew her contract with TVB Tracy Chu was eventually cast as the lead.
Kenny Wong was originally cast in the role, Chan King Wai, but due to a schedule clash, Pal Sinn replaced him.
