It's the first day of term and six graduate trainees who have never taught before are thrown in at the deep end. Oxford graduate Charles is teaching at the Archbishop Lanfranc School in Croydon, a rundown and overcrowded comprehensive. Charles faces a huge workload of 500 students a week to teach, some of whom have only just arrived in the country and cannot speak English. Nick and Meryl are both teaching at the Harefield Academy, a school in a traditional working class community. Meryl teaches English and is shocked to discover that some of her Year 9 pupils cannot spell even four-letter words. Maths teacher Nick faces an uphill battle with apathy as some students admit they simply can't be bothered to learn. Oliver is on a mission to inspire his charges with poetry and music, if only he could remember the words. Claudenia's first science lesson goes with a bang, but it's not long before she's reduced to tears at Crown Woods College in Eltham.

The young trainees are a month into the job and the enormity of the task ahead is just starting to sink in. The honeymoon period is over with the students and the new teachers quickly have to work out a way to keep the kids engaged so their behaviour doesn't go downhill. Charles has clashed with one pupil in particular. Caleb came from a pupil referral unit after being excluded from mainstream school three years ago. He finds Charles's RE class boring and refuses to do the work. The school calls a meeting to try to sort out their differences, but the day will end in tears. Meryl has wanted to be a career teacher all her life, but her first term is not going well. The behaviour of some of her classes has gone downhill and the school have had to draft in extra support. When classes fail to improve Meryl is warned that her job could be at risk.

The trainees have been in the job for two months and as the end of their first term approaches it is clear that some are progressing more quickly than others. Meryl is lagging behind at this stage and has been warned by the school that she needs to show signs of improvement in her teaching or she could lose her job. Her lessons will be observed, but it's not long before her troublesome Year 10 class gets out of hand. Harrow-educated Nick has progressed well as a teacher, but struggles with the behaviour of one Year 10 lad in particular. He hopes that a day in the countryside shooting pheasants will improve relations with Zac. In Croydon, geography teacher Chloe faces the challenge of getting her low-ability GCSE class to knuckle down for their mock exams.

It is the start of a new year and a fresh term for the trainees. Sadly for Chloe's Year 11 class it is also the results of their mock exams, and the news is not good. Chloe has to deploy every trick in the book to get the class back on track and she starts by telling some hard truths to their mums and dads on parents' evening. It is also the time of the year for school trips. Oliver has hatched a plan to inspire his business studies group by taking them to Greenwich University, where he hopes the august surroundings will rub off on them. Charles decides to take a bunch of his Croydon students on an ambitious five-day trip to a farm in Wiltshire. He hopes that the change of scenery will make a difference to their behaviour in class, particularly that of class clown Walid.

The trainees are approaching the end of the spring term and the pace of working life is relentless. Science teacher Claudenia is in a gifted and talented school, but a clique of Year 10 girls are becoming impossible to manage. They have taken against her and their lack of respect her is starting to show in the classroom. Claudenia must decide whether a confrontation is the best solution. As the term ends, she begins to question whether teaching was the right choice of career. Maths teacher Nick has taken on a life-skills lesson, which means he must explain about the birds and the bees to his impressionable Year 7 pupils. Unluckily for them, Mr Church knows nothing about the topic so has to draw on fellow trainee Meryl for back-up. At Lanfranc school in Croydon, a fight outside the school has serious consequences for one of Charles's pupils.

The trainees are approaching the end of the academic year and, for some, the momentous decision of whether to stay in teaching. Chloe is in the second year of the Teach First programme, her two- year commitment is nearly up and she faces the dilemma of whether to continue at the school or follow her ambition to go travelling. Maths teacher Nick has been balancing a long-distance relationship with his job at the Harefield Academy, and with his wedding looming he too must make important decisions about his future. Claudenia receives a surprise invitation for her and a pupil which will change the way she thinks about her job. The end of term also means exams - and results. The teachers finally find out if they've made an impact in the classrooms and affected the lives of the kids they teach.