Mr Malone teaches the class about the women's movement and feminism. When a photo of Martha in the school prospectus is photoshopped to remove a spot on her chin she is outraged. Ollie had a spot in the same photo and his was left intact. She and the others decide to take action and, like the Suffragettes before them, they chain themselves to a public building in protest - in this case the school bike racks.

In the process, a competition develops between Ollie and Martha as to who is the most persuasive feminist campaigner. Meanwhile, Mrs Griggs' latest obsession is underwater karate. She's determined to win the UK Underwater Karate Championships and forces a reluctant Mr Malone to become her training partner to help her win.