Undercover Hong Kong Police Force officer Chan Wing-Yan seeks to uncover the link between Hong Kong Triad boss Hon Sam and the mysterious Mainland Chinese gang leader Shen Cheng. Since Hon's ascension to the seat of triad boss was due to the death of his predecessor, Ngai Wing-Hau, Hon is suspicious of all his men for fear they might usurp his position. He tests Chan's loyalty by ordering him to smash an ashtray on Shen's brother during a negotiation, resulting in Chan's arrest by Inspector Yeung Kam-Wing. Yeung tells Chan that though Chan does not recognise him, he recognises Chan and he warns the latter to "be careful". Chan is released after both Hon and Shen fetch him at police headquarters.
