We're back with the pupils and teachers this evening as Ms Postern signs up for a triathlon before she knows that it actually involves. Of course, Mr Gunn offers to help her out with her training, sparking Mr Church's jealousy in the process. He develops a sudden interest in exercise so he can keep an eye on the pair: We're sure that'll go a long way toward wooing her... Elsewhere Mrs Klebb decides its high time to take action against violence at school, but it isn't exactly clear whether she'll get support from her colleagues or not...