School resumes after summer vacation. Some of the Form 4D students are punished by the principal for ill-discipline. Form 4A despises them as a class of poor records. Form 4D is going to strike them back an eye for an eye. Being the class-mistress of Form 4D, CHING is held responsible for their demerit. Owing to the silence of the Form 4D students, there is no clue for investigation. BONG comes back to Hong Kong to continue his studies. He lives in DOCTOR NGAI, his guardian's house. BONG feels hard to adapt since NGAI is a very strict man. He enters Form 4D under the arrangement of NGAI. BONG is mistaken as the spy sent by CHING, so he is isolated by his fellow classmates. The guys trap BONG by a silly trick. CHING is anxious to learn the truth.

BONG prefers punishment rather than telling the true story. The Form 4D guys are moved by BONG's bravery. They feel sorry to make BONG the scapegoat. They try to reconcile with BONG but he neglects them. Once BONG fights with one of the students and CHING wants to talk with their parents. YAN accidentally breaks the news to her parents that BONG is punished in school. BONG is therefore reproached by DOCTOR NGAI. BONG blames YAN for being too frank. When CHING comes to know about BONG's life style, she asks for an interview with CHAU.