The five members of the band the Wynners are all packing up, ready for a singing tour in USA. Uncle Kau, a boss of a triad, planning to exchange their guitars with narcotics inside with the Wynners', so that their narcotics can be carried to USA. But he fails, as the Wynners has to cancel their plan, for a fire broke out in the night club. Uncle Kau thus dispatches three of his followers Wo, Anny and Jane to steal back the guitars. They fail again even though they've tried their best. When the Wynners finds out the narcotics in the guitars, they report it to the police and are required to help the police with the case.
It comes to the time when the Wynners performs at the City Hall. Wo sneaks in and steals the guitars but follows by Anthony, a member of the Wynners, who notices it. The other then follow as they find it out.
When Anthony enters Uncle Kau's castle, he's discovered and overpowered but fortunately rescued by the other four. Uncle Kau and his men then are under arrest finally.