Please Sir! - Season 4 (1971)

New supply teacher and former army Captain Mr Dix runs his class with military precision and rules his class with a regimental authority. He even has the headmaster agreeing to his long list of orders for gymnasium equipment. However his authoritarian way of running the class alienates the rest of the teachers, but fortunately for all Dix catches a dose of chickenpox which is working its way around the estate.

Quirky unorthodox and hippy-like teacher David Ffitchett-Brown is a big hit with the class and a bit of an enigma to the other teachers but has seriously ruffled the feathers of fellow teacher and former Army captain Mr Dix. Ffitchett-Brown takes every opportunity to make a fool out of Dix.

David Ffitchett-Brown presents a list of teaching aids he would like the headmaster to authorise for purchase, which he does, and Potter is despatched to purchase the required items. When Ffitchett-Brown finds out that some of his class are playing truant he sets off to the local billiard hall to persuade them to return. Meantime some of Potter's purchases turn out to be a bit questionable.

The headmaster needs time to write his speech for a forthcoming rotary club event and asks Doris Ewell to take on his admin duties, which she refuses. David Ffitchett-Brown wants to take the class outside for a re-enactment of the charge of the light brigade but the headmaster has cancelled all games periods, so he takes the class to the cinema to see it on the big screen.

Mr Price feels under appreciated at Fenn Street school and, as he has done previously, thinks it's time to move on to better things. The rest of the school staff have a bit of fun with him when looking through the newspapers helping him find a new job. The headmaster thinks he's about to lose a valued member of staff and tries to convince him to stay with extra incentives.

The headmaster gives Potter permission to advertise for an assistant. He hasn't, however, countenanced the prospect of a young, fit, enthusiastic and efficient black man, Sidney Noakes, Derek Griffiths turning up for the job. Before long Potter fears newcomer Sidney is after his job.

Weever Street school is closing down and a number of their pupils are being transferred to Fenn Street. However they are rowdy and badly behaved and the teaching staff have trouble keeping them under control. It seems that the closure is part of a bigger plan to merge three local schools including Fenn Street into a large comprehensive school. Potter has to decide where his loyalties lie when the new comprehensive Headmaster is chosen.

There is the school inspection to be organised, and the new Weaver Street kids to keep under control, but they are determined to sabotage the inspection. Doris is seeking solace in the company of the school's careers officer Mr Sibley, until her mother turns up at the school and starts to cause trouble by mistaking the school inspector for Mr Sibley.

Following new rules that ban long hair on boys and short skirts on girls, the pupils led by the Weaver Street group decide to hold a protest to protect their rights.

After 25 years Potter has been given the honour of standard bearer for the Fenn Street Old Comrades Association at the annual El Alamein reunion. However a visitor from the past casts a dark shadow over Norman's celebrations.

Headmaster Cromwell's latest idea is a competition for a new school song to commemorate the first meeting of his newly-formed Old Fennians Association and the teachers compete with each other to come up with a winning song. Meantime the original Form 5C are invited to join the Old Fennians Association and regroup for the big event. The Weaver Street kids act as the backing choir for the competition.

The headmaster's "Clean Up Fenn Street" campaign is in full swing. Godber is ordered to assist Potter with waste collection but his incompetence and inability to differentiate between combustible and non combustible materials leads to an explosive situation which threatens to clean up Fenn Street for good when everything is dumped into the incinerator.

Miss Petting has started a dance class and is trying to teach the class a new dance, but it's all too old fashioned for them. She feels unloved and decides to unburden her feelings on the headmaster, who displays an uncharacteristic romantic streak. The teaching staff, as the Fenn Street Rotary Club, put on a concert, The Mikado. Daisy is expecting a 'handsome prince' as her date for the evening, but he's not quite what she thought he'd be.

Fenn Street School football team wins its semi-final tie of the district cup and makes history by reaching the final for the first time. Miss Ewell has given one of the pupils detention unaware that he's the team's star player and will therefore miss the final. The headmaster orders her to reinstate him, but her stubborn streak refuses to comply. Will she relent for the sake of the school's reputation.

Fenn Street School holds a charity walk for the local old and needy, but a number the boys are so unfit they barely made it over the line. The staff count the proceedings and over £100 is locked away in the safe, except that the safe doesn't lock and the money has gone. Will it be found it time before local dignitary Sir Giles Hardwicke arrives for the donation ceremony.

Headmaster Cromwell gets a sexy blond secretary, Miss Nately, whose appearance gets the boys and the male staff all hot and bothered. Mr Price is so taken with Miss Nately he spends all of his time in a romantic daze and dreams of having a date with her. As things turn out, because of her incompetence, she is about to lose her job thanks to the headmaster and the the chairman of the Fenn Street School governors.

Terry Stringer's dad is in prison for bank robbery, and one of the teachers, Mr Price, gave evidence at his trial. Now that he's out, young Terry expects his dad will head for the school for revenge against Price. Someone tough looking does turn up looking for Price, but it's a case of mistaken identity.

Wedding bells ring out for Miss Ewell and Mr. Sibley. Meanwhile, Potter's ding-dong with his wife Ruby ends in a fly-away flourish.