LING HO-LEUNG and FONG CHEUK-LING are found dead in a car. Police say they are likely victims of carbon monoxide poisoning while having sex inside the car. YIP LAI-CHU, LEUNG’s mother, puts all the blame for her son’s death on her daughter-in-law, SIT CHI-YIU. She believes her son will not have an affair if YIU has treated him good. LING’s husband YIU LAP-TIN does not believe at all that his wife had an affair. He pretends himself as LEUNG’s old school friend and starts to find out any clues from LING’s family. TIN rents a flat next to LING’s family and installs surveillance camera. During his investigation, TIN finds YIU has worked very hard to support the family, she even sells her wedding jewelry in order to get more money. YIU receives a letter and a flash memory drive which are the gifts LEUNG had prepared for their third wedding anniversary before he died. CHU believes YIU is having an affair with TIN……
