It's near the end of term at Abbey Grove, and Alfie is prepping for a careers presentation – really just an excuse to reunite all the old Class K and have a big party. Meanwhile Stephen has been teaching at Abbey Grove for six months, but none of his old schoolfriends know this. He has been maintaining the fiction that he is now a musical theatre star on the rise and tells his pupils (the new Class K) that they cannot blow his cover.

Jack Whitehall together with Anthony Joshua and Mathew Horne are here to give us the top tips for home schooling. Learn about Time Management and PE (physical education) with the new characters of the show Bad Education. Do you really need Geography and Maths? Are your quads really on your arms or thighs? Get the answers to all the burning questions on bad education.

With exams over it's careers advice day for Form K, but it is Alfie who makes the biggest decision of all when he realises he can't go on teaching without his beloved class and quits Abbey Grove. Fraser is devastated to lose his best friend and takes the news badly. Alfie reveals he has landed himself a job at the Playstation factory and cannot be tempted back despite Gulliver and his class begging him to return. But will the truth about Alfie's new job be exposed and will they manage to convince him to return to Abbey Grove? And who will be crowned prom king and queen?

Fraser discovers that Alfie never passed his Biology GCSE, so Alfie must go back to school himself to be taught by Gulliver and sit the exam with his own class. It should be the perfect opportunity to prove to Gulliver that he can motivate his class and lead by example, but Alfie decides there is only one real option: cheating. But, with the revelation that the notorious ball-breaking invigilator Mr Hewston will be overseeing the exam, it becomes clear that this is going to be a battle of wits. Meanwhile Martin Wickers is babysitting his girlfriend's dog and Fraser is organising the end-of-exam skip party.

Martin Wickers's attempts to teach Alfie to drive end in disaster when they run over Pod, the school caretaker. Alfie and his class start fundraising for Pod's urgent surgery. However, when the school bully Grayson is transferred to Alfie's class it soon becomes clear that their noble intentions might be difficult with him around. Soon Alfie and his class find themselves no longer leading a charitable enterprise, but being taken on a joyride in a stolen ambulance. While Alfie is giving a tracheotomy after being mistaken for a paramedic, his class spot Pod walking around instead of being in a wheelchair. Fraser has taken up pole dancing and sees the fundraiser as the perfect opportunity to demonstrate his skills. Meanwhile Alfie ends up sexting his dad by mistake after Miss Guilliver's phone is swapped with his, and Alfie tries to find out if she is sleeping with Richard.

It's Abbey Grove's sports day and Fraser has hired the most inappropriate new sports teacher to oversee events – Preet. Alfie sees this as the perfect opportunity to challenge Miss Gulliver's ex-boyfriend Richard to an endurance event, which Preet offers to design. But with a steroid scandal rocking the school and Alfie desperate to win by any means possible, will he make it over the finish line with his dignity intact?

Mitchell announces he is leaving Abbey Grove, but there is the perfect opportunity for a farewell party when Fraser decides to rent out rooms to after-school clubs for extra cash. However, things get complicated for Alfie when he promises to attend Gulliver's book group, Fraser's LARPing club and Mitchell's leaving party. Alfie wants to use the book group as an opportunity to impress Gulliver, but when he gets his class to write the chapter summaries things quickly go from bad to worse. Simultaneously, he has got to help Fraser win a fantasy battle against two very self-important LARPers and survive Mitchell's leaving pranks.

It's summer term and Alfie Wickers is back in high spirits to get his class through their exams. But there is a shock for Alfie with the revelation that his dad Martin Wickers has been appointed as the new deputy head whose first jobs are to increase class sizes and fire a member of staff after Fraser has badly invested the school's money in his own clothing range, Dolce and GaBanter. For Alfie this means a new class member, Cleopatra, and a tough decision to make – stand by his girlfriend, Miss Gulliver when she leads the teachers on strike, or sacrifice himself to save his class from failing their exams.