It was supposed to be the perfect reunion: six university friends together again after 20 years. Host Ali finally has the life she always wanted, a career she can be proud of and a wonderful family with her college boyfriend, now husband. But that night her best friend makes an accusation so shocking that nothing will ever be the same again.

When Karen staggers in from the garden, bleeding and traumatised, she claims that she has been assaulted - by Ali’s husband, Mike. Ali must make a split-second decision: who should she believe? Her horrified husband, or her best friend? With Mike offering a very different version of events, Ali knows one of them is lying - but which? And why?

When the ensuing chaos forces her to re-examine the golden era the group shared at university, Ali realises there are darker memories too. Memories that have lain dormant for decades. Memories someone would kill to protect.