However, his teammates find him to be a real pain in the neck. New comers, YIP CHIN-TING (Kristal Tin) and HO LAI-YIN (Bosco Wong) are especially annoyed by the unconventional way in which he does things. As a result, the pair often has confrontations and misunderstandings with the inspector. Things become worse when SUM learns that his half-sister, CHING PUI-YEE (Aimee Chan) is secretly going out with LAI, and that TING, who has recently been divorced, has a crush on him.