Young teacher Bernard Hedges is determined to improve the new tough East London school that he has been assigned to. This means he has to deal with 5C, the worst class in the school, and Potter the notorious school keeper.
Bernard has to do some quick thinking when someone from the art class shows him their drawings of the pupils of 5c. This would normally be ok, but the artist has, for some reason, drawn them in the nude!
When 5c pupil Maureen is seen coming out of teacher Bernard's flat, the school rumour mill starts working overtime.
The inexperienced Alf finds himself taking over as landlord at the Brown Cow. The return of a Greek Cypriot student causes a lot of disruption within the school. Bernard Hedges tries to deal with the boy with a firm hand and winds up fearing for his life.
Complaints are made about the state of the library, and the noise coming from there, after 5c are given custody of the key to the door.
Bernard is surprised when he finds out that the new trainee teacher is an old girlfriend. When she becomes more successful at dealing with 5C than he is though, he starts to see her as a threat.
As the end of term approaches, Bernard wonders what the students will give him as a Christmas present. And then he finds out that 5C's old teacher has recovered and will be returning to teach them next term.
The pupils of 5C discover that maths can be more profitable that they first thought.
A member of staff from the school is under suspicion, after Sharon is attacked while walking home across the common.
Bernard's attempts to raise interest in the PTA are thrown into chaos when a young Indian student joins 5C
Bernard uses his new position as sports master to help Duffy out with a problem.
When 5C decide to adopt a Jerboa, the sight of the animal causes Potter to reminisce about his time in the army as a Desert Rat.
It's the annual Fenn Street Open Day, and as usual, it causes nothing but trouble for Bernard.
bernard arranges for 5C to help out at an old folks home.
Miss Ewell is thinking about leaving the school and emigrating to Australia.
Mr Cromwell's decision to split the school into houses, causes a few problems for Bernard.
Bernard tries to come up with a solution when the pupils start complaining about the school dinners.
Abbott gets in trouble with the police, when he acts like Duffy to try and chat up a girl.
5c and Bernard plot revenge on Miss Ewell, after she sends them home for a change of clothes, before they will be allowed on the trip to the theatre.
Mr Hedges takes his class on a field trip, with disastrous consequences.
Bernard has to say goodbye to his 5C class at Fenn Street School but his new class (4C) brings some unexpected problems.
Now that 5C have left, Bernard is seriously considering resigning to spend a year at university. All he lacks is the courage to hand in his resignation — so Penny decides to do everything in her power to force him.
The pupils decide to produce their own revolutionary magazine.
Chaos reigns when a supply teacher arrives with strong ideas about discipline and physical fitness.
The school is agog when new young teacher David Ffitchet-Brown takes on the bullying gym teacher Mr Dix.
New teacher Mr Brown attempts to recapture two notorious truants.
Mr Brown takes 4C on an outing to the cinema, and manages to lose the entire class.
The fed-up members of staff find a new job for Mr Price.
Potter's prejudices are challenged when he is given a new black assistant.
A visit from the school inspector rouses the children to rebellion.
Cromwell clamps down on boys' long hair and girls' short skirts, sparking a pupil rebellion.
Against all odds, Potter gets his way and is voted in as standard-bearer.
Cromwell's idea of a day for Fenn Street alumni is greeted with little enthusiasm, until he offers a prize to whoever composes a stirring school song.