A student LAM SZE YAN is caught red-handed in a bookstore by BUD for shoplifting. YAN’s teacher MOP asks BUD to give her a second chance; YAN is released. However, the school comes to know about the incident and YAN is expelled. CHU bumps into her secondary school teacher MOP, whom she used to admire. CHU finds that she is still very fond of him after all these years. MOP visits CHU. CHUN, PO and NI seize the chance to chat with MOP; CHU is displeased. MOP recommends YAN to work at CHU’s cafe; CHU agrees reluctantly. CHU’s diamond ring is gone. Everybody is saying that YAN has stolen it. PO searches through YAN but finds nothing. While investigating in a shopping mall, BUD sees YAN stealing a wallet from a strong man. He therefore asks PO to come and check it out. PO searches through YAN’s belongings and still finds nothing. YAN dies mysteriously. PO and her boss CHAI KWOK YUNG are in charge of the case. They ask for BUD’s help as well……