Zhang Cheng
Team B leader ASP Chong Yee Tat and his partner SSI(2) Yu Chong Nam are part of the elite Special Investigations Section in the CID. Yee Tat's work often takes him away from his wife Yongmei and their young son. Five years ago Yee Tat failed to crack a case in time and the suspect strangled his daughter before being apprehended. The girl was resuscitated but suffered irreversible brain damage. This case and the burden of having to juggle professional commitments with family life become a source of guilt for him throughout the series. ASP Zhang Cheng Ling, an officer with the Police Coast Guard, was transferred to his team and is determined to prove herself in a mostly male team and overcome Chong Nam's prejudice about her.