Sun-hop and his chums promptly go to see Siu-yau, who turns out to be Ho-yan’s schoolmate. She caught sight of Yat-tung and Mei-ching having some hanky-panky when the incident took place. Po-chai finds out Heung-wing was involved in some sex crime. But Heung-wing had an alibi. Sun-hop urges Yat-ha to come up with some way to collect Heung-wing’s DNA. Ching-mui pretends to be a masseuse. She obtains Heung-wing’s blood and takes it to a lab. Siu-yau goes to court to testify. But her testimony is questionable. Blood test results indicate Heung-wing’s DNA is different from the DNA in the condom beside the human remains. Yat-tung tries to take his own life. Sun-hop blames himself as Yat-tung passes out and is taken to hospital. Yat-ha finds out Heung-wing wants to smuggle himself out of Hong Kong. While the duo are scuffling, they fall into the sea. Po-chai rushes to the scene and saves Yat-ha. She also arrests Heung-wing and seizes this chance to collect his saliva.
