Lam Kwok Kuen, nearing retirement and raising a mentally challenged son by himself, is a police officer whose sole requirement on the job is oversee the department fleet. Despite this, he remains active in the front line of police service, putting his life on the line for the sake of others, his heroism bettering even the most seasoned professionals. He fights the bad guys, putting criminals behind bars, upholding the law at any cost, for as his adage proclaims, to live a day surmounts to pursuing justice relentlessly, whether life or death proceeds in its aftermath.

Mainlander & financial analyst Cheng Zixin (Gao Yuan-Yuan), who followed her then boyfriend Owen (Terence Yin) to Hong Kong, runs into her ex-boyfriend while riding the bus. Owen is now with his pregnant wife and when his wife spots Owen talking to his ex she she freaks out. Cheng hurriedly gets off the bus and, being in a daze, is almost run over by a car. A haggard drunk named Fang (Daniel Wu) then saves Cheng. Meanwhile, in a nearby car, sits CEO Cheung Shen (Louis Koo) who watches everything that transpires. CEO Cheung Shen is a playboy who also works in an office building directly adjacent to Cheng Zixin. Cheung Shen soon starts to woo Cheng Zixin by sending messages to her through the window of his office building. The drunk haggard Fang, who saved Cheng Zixin’s life, runs into Cheng Zixin a few weeks later. It turns out that the drunk haggard is a Canadian-born top architect going through personal problems. They soon become friends.