Rebecca, Daniel, Alex and Isabel have been best friends since university. Rebecca married Daniel, Alex married Isabel and, for twenty years, they have been inseparable. 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 there's more upheaval to come in Rebecca's life as her emaciated, neurotic, self-obsessed colleague, Lorna - her arch nemesis at work - suddenly becomes a regular feature in her social life.
Rebecca's once-happy foursome is now a distant memory and with hearts broken and friendships fractured, it seems that change is never a good thing. Or can it?