When Josh does badly in a test, he explains to Brian and Sophie why he failed: A teacher's job is to teach you things. If Josh doesn't know anything, it must be the teacher's fault for teaching him badly. So Brian decides to see if he can make a better job of Josh's education – by taking Josh out of school and teaching himself from home. At first Josh thinks this will be a real doss, but he soon finds out that Brian is a really strict teacher. But when a big test is looming Josh finds out that there's no alternative to hard work. Meanwhile, Mel stresses out over her final exam and Trent tries to teach her some relaxation techniques – but she finds the best way to relieve her stress ids to beat Trent up! And elsewhere in school, Lucy struggles to master the euphonium for the school brass band, but finds that this is one thing she isn't a genius at. But after sulking at her failure she makes the best of it and plays the triangle in the band.