Rookie teacher Nathan Carter starts his first day working at his former school, and takes charge of the after-school detention class.
Josh notices that Nathan is more than a little interested in music teacher Miss Poppy and her modern take on Cinderella.
To get out of maths homework, Josh claims he has number blindness and persuades novice supply teacher Janucek to let him off.
The school disco means just one thing for the Carter brothers, girl trouble. Only Ash has any success with the girls. In fact, more success than he can handle.
When Nathan's laptop mysteriously breaks down, Josh is the obvious suspect. Josh dodges the problem by suggesting Nathan borrows a replacement.
Nathan takes advantage of Mrs Carter's weekend trip away to invite Miss Poppy round for a romantic evening. Unfortunately, Josh invites his class over for a party.
Josh, Ryan and Ash sign up for the school football team to get out of lessons, but discover that even studying is preferable to PE.
Nathan drags Josh onto the useless school quiz team to teach him how to stick at something.
When the school's last remaining keyboard blows a fuse, Josh decides to help raise funds for new musical instruments by staging a charity auction.
Nathan gets lumbered with running the school council and drags Josh in to teach him about responsibility. But instead, Josh uses his new powers to try to change the rules to his own advantage.
Someone is running an unofficial tuck shop selling crisps and chocolate, and Nathan is given the job of finding out who is behind it.
When Nathan decides to put Darius, the star of Elmsbury's basketball team, in detention, Darius decides to get his own back - on Josh.
It's the end of term and Nathan is due to be assessed by headmaster Mr Byron. When Josh messes up, it looks like Nathan's career as a teacher is over.