Li Jia tells Cha Cha about the strange occurrences. She had revealed to him about the death of a son and his mother who had committed suicide after suffering from psychiatric troubles. The supervisor tries to prevent him from returning and he starts to suspect foul play. Prof. Vincent Chan continues his observation. Li Jia finds her working at a restaurant with a strange group of colleagues. They help him find out the wherabouts about the previous tenants. He is left upset after coming to know that the family was bullied. That night, he once again sees the cats and finds a strange substance near his window. Shi Cheng examines it and confirms it to be a human nail. Further observation of his neighbours reveal that a man named Ng Hung was the one feeding the cats. On visiting his old workplace, Li Jia learns that he had raped a coworker, who was the single mother who had lived in his flat. He plans to catch a glimpse of the neighbour whom he suspects is the killer, but is instead shocked to see the building's supervisor in the room.