TO and his wife LAM have been lurked and attacked by a mysterious man three times. They are frightened and they inform the police. When it is the second time for TO to go to the police station, LAM is killed in their house. Some background information of the couple has been collected. LAM is the foster daughter of a billionaire. After the rich man's death, LAM and the rich man's son CHI had an argument in the right to inherit the fortune. The court gave LAM the right and CHI hated LAM. CHI tries to hide where he was when LAM was killed but his lie is spoiled by the employee IVY. At last he has to admit that he was with a male prostitute when the crime was committed. It proves that he is innocent and the killer is someone else.