A sumptuous wedding banquet is being held in the ballroom of a luxurious hotel. While the bride CHO LAI-MEI and her father CHO KING-TIM are waiting in the bridal room, a shot is suddenly fired. Senior Chemist of the Forensic Science Division PO KWOK-TUNG is summoned to the hotel to collect evidence while playing with his daughter. LEE CHIN-FUNG and LING SIN-YEE of the Regional Crime Unit find three corpses upon their arrival at the ballroom. Later YEE discovers one more body under the table. After receiving a call from her teammate, YEE goes to another hotel room to have a look. TUNG follows her to the site, and after a careful investigation, they believe that one suspect is in hiding. While Senior Forensic Pathologist CHUNG HOK-SUM is conducting an initial examination, the ceiling spotlight hanging over one of the corpses becomes unfastened and falls down suddenly. Suspect CHI-WAI is questioned by FUNG and YEE.… ...

All the evidence at hand suggests that FU is the killer’s real target but it is still incomprehensible why the bride ends up being shot instead. YEE and FUNG go to see FU but are shocked to see him being pursued by a man. YEE takes FU to the emergency room, where they run into SUM. SUM notices a dark red scar on FU’s waist and quickly tells YEE about this. Scientific Evidence Officer CHEUNG CHEUK-KWAN examines the stain left on the clothes of one of the shootout victims HO-LEUNG, and later determines that it is bluefin tuna oil. YEE learns from the sushi chef that LEUNG had come to see his apprentice CHI before his death. SUM has accidentally spilled some coffee on a girl named CHEUNG-LING at a convenience store, who is later found to have vitiligo on her face. SUM stalks LING for a while and catches her meeting CHI in secret. YEE and FUNG go to see TIM. But before they can reach him, TIM has fallen off the rooftop.