薛家強繼續為刑事情報科執行任務，打擊不同罪犯；而卓凱因三年前槍傷犯罪集團主腦錢瑞安而被判入獄三年，在刑滿出獄後並選擇與妻子莫羨晴開設咖啡店安穩度日，卻面臨被黑幫追殺的危險。另一方面，情報科總督察章紀孜與卓凱的前臥底鄭淑梅卻懷疑卓凱意圖投入黑道；暗中著手調查卓凱與黑道人士的關係......家強與卓凱偵查人口販賣案件，保安局首席調查員韋作榮合力偵破；保安局新設立的情報科邀請徐天堂加入，卓凱人在江湖，捲入黑幫話事人選舉。昔日夥伴卻以另外一個身份去參加選舉，卓凱重遇應為已經被家強槍殺的老對手覃歡喜，並發現韋作榮的真正身份是昔日敵人魏德信之親弟魏德禮，他正計劃對眾人報復，眾人合力調查；揭發了一個個龐大的黑暗勢力，頓時一股風雲再次步步緊逼著......
Aliases
Set in Hong Kong, China, four years after the events in Line Walker, Sit Ka-keung (Raymond Lam) continues to work as a Hong Kong Police Criminal Intelligence Bureau (CIB) undercover officer, while Cheuk Hoi (Michael Miu) opens a coffee shop after being released from prison. CIB Chief Inspector Cheung Kei-gee (Mandy Wong) suspects Check Hoi of joining the triad and investigates him. The Security Bureau establishes Security Intelligence Agency (SIA), a new intelligence department. The principal investigator of SIA, Wai Chok-wing (Kenneth Ma) invites Tsui Tin-tong (Benjamin Yuen) to join SIA. Chum Foon-hei (Benz Hui), who was thought to be killed by Bao Seed, returns to Hong Kong to track down the leader of an international crime organization, Eternity. The true identity of Wai Choi-wing is later revealed to be Ngai Tak-lai, the younger paternal half-brother of Victor Ngai Tak-shun...
Aliases
- Line Walker 3
- Line Walker III
薛家強繼續為刑事情報科執行任務，打擊不同罪犯；而卓凱因三年前槍傷犯罪集團主腦錢瑞安而被判入獄三年，在刑滿出獄後並選擇與妻子莫羨晴開設咖啡店安穩度日，卻面臨被黑幫追殺的危險。另一方面，情報科總督察章紀孜與卓凱的前臥底鄭淑梅卻懷疑卓凱意圖投入黑道；暗中著手調查卓凱與黑道人士的關係......家強與卓凱偵查人口販賣案件，保安局首席調查員韋作榮合力偵破；保安局新設立的情報科邀請徐天堂加入，卓凱人在江湖，捲入黑幫話事人選舉。昔日夥伴卻以另外一個身份去參加選舉，卓凱重遇應為已經被家強槍殺的老對手覃歡喜，並發現韋作榮的真正身份是昔日敵人魏德信之親弟魏德禮，他正計畫對眾人報復，眾人合力調查；揭發了一個個龐大的黑暗勢力，頓時一股風雲再次步步緊逼著......
