Ng Yan-Ting

Hong Kong Customs and Excise Department officers Chow Ching-lai and Cheung Wan-nam share a close mentor-student relationship. On a case involving seized smuggled arms, Ching-lai is sent to take part in a joint operation with Interpol to capture a reclusive arms dealer. However, Wan-nam makes a drastic decision that further complicates the case.

Sunny is a naïve circus performer who dreams of inheriting his father's knife-throwing skills. However, his hostile colleagues continue to bully him, relegating him to a lowly clown. On a tour to Malaysia, Cheung and other performers discover a cave occupied by the Japanese army during World War II. Instead of finding treasure, the performers - including Sunny - are sprayed with a mysterious chemical that turns them into superhuman mutants...