Two brothers, Yat and Leung, with different mothers have different fates. After Leung and his mother being expelled from the family, they are housed by a feng shui master. Leung is a lucky guy and brings a good fortune to his mother. On the other side, Yat's presence poses a tragic threat to his family. Eventually, Yat's parents die and Leung's mother decides to raise Yat and the two boys exchange their names. However, their lives will turn upside down when they reach the age of thirty. The only way Yat can retain his luck is to overtake all the good luck from Leung.
A Shanghai doctor named Tangsan, is trying to help the town's poor people. Meanwhile, he has the murderous Axe Gang to deal with as well as his feelings for the gang leader's sister.
Hotheaded cop Bill Zhu (Lau Ching-wan) gets relegated to the Emergency Unit after a dustup with his inept boss. When the mob kills Zhu's pal and ex-colleague (Francis Ng) during a turf-war hit, he rounds up his motley department cohorts and embarks on a mission of revenge against the gangsters. The pursuit of the baddies culminates in a hair-raising showdown atop a hijacked transport plane in this action thriller.