Protege (Moon to)

One Night in Mongkok director Derek Yee takes a trip into the underworld with this crime drama starring Andy Lau, Lewis Koo, Daniel Wu, and Anita Yuen. An undercover cop infiltrates a major heroin ring, skillfully ascending the ranks from low-level dealer to middle management.

After falling for a beautiful addict, the policeman is hand picked by the ailing crime boss to take over the entire syndicate once he's gone.

His priorities blurred by an infernal combination of money, power, and seven years undercover, the cop chosen to clean up the streets finds his true identity gradually slipping away as a malevolent new persona begins to take hold.