Rebecca, Daniel, Alex and Isabel have been best friends since university. Rebecca married Daniel, Alex married Isabel and, for 20 years, they have been inseperable. But all that is about to change... When Alex walks out on Isabel Rebecca thinks things can't get any worse. But then she finds out the reason why and she's left harbouring a secret she'd rather forget... And not only that. Alex's new girlfriend just happens to be Rebecca's skinny, neurotic, self-obsessed colleague, Lorna, her arch nemesis at work and now a regular feature in her social life too. They say you should keep your friends close and enemies closer but sometimes your best friends can become your worst enemies...