導演：劉偉強
Director: Lau Wai Keung
　　一個傳奇的誕生，始於我們最好的時代。究竟重案組督察黃志誠\ (黃秋生) 與黑幫頭領韓琛 (曾志偉) 如何結怨？警校畢業生陳永仁 (余文樂) 與黑幫臥底劉建明 (陳冠希) 的宿命糾纏何時開始？關鍵繫於三個人身上：琛妻Mary (劉嘉玲)、新任黑幫龍頭倪永孝 (吳鎮宇)、及重案組高層陸啟昌 (胡軍) 。通往無間道之門由此打開，一切將終結於最壞的時代……
　　A legend is born at the best of times. From the multiple award-winning team behind the mind-blowing blockbuster, the secrets are finally revealed in this most anticipating prequel: What drove police superintendent Wong (Anthony Wong) and crime boss Sam (Eric Tsang) against one another? How did two struggling moles Yan (Shawn Yue) and Ming (Edison Chen) begin their parallel fates? The keys lie in the hands of three: Sam’s wife Mary (Carina Lau), ruthless kingpin Hau (Francis Ng), and righteous cop Luk (Hu Jun). The infernal gates are open to the worst of times….