Ray Lui heads a team of undercover cops, including Mark Cheng, Wong He and Simon Lui, who travel to Malaysia to discover the fate of one of their own. That cop, played by rising star Daniel Wu, was a friend and even a student to some of the cops. Their fear is that he could be dead. Their even greater fear is that he's been turned from cop to criminal, and is now a violator of the laws he once swore to uphold. Could he have been turned, and if so, can his friends kill him if necessary? An interesting cast of familiar HK Cinema names (including Chapman To and the late Blacky Ke Shou Liang) populate this fine thriller from director Billy Chung (My Schoolmate, the Barbarian and Shiver). An intriguing storyline rife with touches of human darkness make Undercover Blues a prime Hong Kong thriller!