A group of illegal immigrants escape from China to Hong Kong, but are taken advantage of by the locals: the only girl in the group is raped by a member of the gang that helped in their escape, and her Elder Brother and the others are paid 20% of the wages in their hard tasks. Unnable to survive on their honest works, they switch to petty crime: shoplifting, bill shirking, and pickpocketing. The good girl and impressive pickpocket shows off the kung fu her mother taught her, and picks the Chief Detective's pocket, just as he was looking for a new mole to infiltrate the criminal Eagle's gang. The immigrants are reluctant at first but are convinced to cooperate with the Police with the promise of not being deported to China. Besides, the No. 1 hit-man of the Eagle Gang is the same man who raped Hsiao on her way over to Hong Kong, and the girl is determined to settle the score out of the courtroom. The infiltration goes so well that Hao, the Eagles' Boss, gets interested in the girl, ...