Meet the girlfriends! Polly, Keri, Frizz and Lily. They're the Gang of Four, and they're going to stick together for ever and ever! But, why then does Keri keep inviting her new school friend, Jemima, to their special Saturday 'Gang of Four' meetings? And why is Frizz behaving so strangely? Polly can't help wondering what her friend isn't telling her. Can the girlfriends make everything groovy again?