Jake’s nervous about starting his new school. His class teacher, Mr Hyde, is new too but, unlike Jake, he has a reason to be worried. Although class 5b quickly decide that Mr Hyde is the best teacher they’ve ever had, they also discover a problem – whenever he experiences a strong emotion Mr Hyde starts to glow and transforms into a naughty, farting, biscuit-loving creature. Suddenly their teacher is wrecking the classroom and they need to work together to find a way to turn the creature back into their teacher before their evil headmistress finds out.