Brothers Chung Shun and Chung Ching are both serving members of the Criminal Intelligence Bureau (C.I.B.) of the Hong Kong Police Force. Shun is responsible for technical espionage like phone-tapping and eavesdropping and the recruitment of informants while Ching is to conduct intelligence analysis and assessment. C.I.B. works closely with various units in tackling organized crime syndicates and has made a quiet yet significant contribution to the Force. Serving as Intelligence Officers is absolutely challenging and has put Shun and Ching under great stress.