Chief Inspector of the CIB who uses unconventional methods to protect undercover agents. After a mentor's murder, he secretly locates deleted operatives while hiding police corruption. A failed 2010 Bangkok mission shifts his focus to training Cheng Suk Mui. Later imprisoned, he opens a café and faces internal scrutiny over alleged gang ties.
Central adversarial relationship driving the season's core conflict, defined by criminal expansion versus law enforcement pursuit.
His survival instinct ultimately overrides his professional duty, driving the central conflict.
Deceptive professional relationship that unravels into a tense cat-and-mouse investigation as Cheuk Hoi uncovers the internal spy.
Professional handler relationship that deepens into personal loyalty and romantic tension through shared undercover risks.
Strict professional chain of command strained by the psychological toll of deep undercover work and triad infiltration.
Professional partnership that transitions into a romantic relationship, complicated by overlapping undercover assignments and police secrecy.
Strategic alliance built on mutual benefit, where Ngai Tak-lai / Wai Cho-wing supplies actionable intelligence in exchange for police protection.
Compassionate civilian relationship where Cheuk Hoi provides protection and legal guidance, fostering mutual trust and emotional closeness.
Familial-social bond where Tseung Kei-tsz (Madam G) offers a grounded, supportive presence that stabilizes the chaotic undercover ecosystem.
Explore the full interactive character relationship map of Line Walker