MING suddenly feels unwell while trying to catch the man who shot YUEN. The case is assigned to YUE for follow-up actions. MING blames KIT for failing to hold on with what he was suspecting in the beginning. MING thinks that MING is the one who caused YUEN's injury and he wants KIT to leave the Investigation Unit. LUN discovers a suspicious mainland visitor. FUNG carries out investigation on him and he successfully arrests NGOR. KIT wants to transfer to another department but his mind changes after learning that FUNG has successfully arrest the key person who arranges bogus marriages. KIT declares to MING that he is determined to stay in the unit. YUE discovers some important hints of the hotel murder case from KIT and he checks out KEI's file secretly to look for information. KEI discovers an illegal worker without any identity and she asks the Investigation Unit to help……