Prequel to the Hong Kong gangster thriller 'Infernal Affairs' (2002), set ten years before the events of the original film. Chen Ying Yan (Shawn Yue) has just become an undercover cop in the triads, while Lau Kin Ming (Edison Chen) is a new recruit to the police force. Bitter enemies from the first film, Inspector Wong (Anthony Wong Chau-Sang) and Sam (Eric Tsang) are behaving like old friends, while Yan is embroiled in the family saga of a triad cartel, and Ming has developed an oedipal fixation on his boss's wife. As friendships fracture and foes join forces, nothing is as it first appears to be...

Hark Tsui directs this lavish period action thriller set during the Tang Dynasty in Ancient China. Andy Lau stars as the titular Detective Dee, recently released from prison after an eight-year sentence for challenging the ascendancy of the soon-to-be-crowned Empress Wu Zetian (Carina Lau). After a series of suspicious deaths at court, the Empress herself releases Dee and orders him to investigate the deaths in time for her coronation ceremony. With the questionable assistance of the Empress's servant Jing'er (Bingbing Li) and albino police officer Pei Donglei (Deng Chao), Dee sets out to untangle the conspiracy and reinstate himself at court.