1995年夏天，两个纤弱的少女卷入一起教师谋杀案。17年过后，两人经历着截然相反的人生。名为Poppy的女孩被判有罪锒铛入狱，而另一名女孩Serena却结婚生子过着美满的生活。现在，她们却不得不再次面对当年共同经历的黑暗青春。

Deux femmes, Serena Gorringe et Poppy Carlisle, accusées du meurtre de leur professeur alors qu'elles n'étaient qu'adolescentes, se retrouvent, dix-sept ans plus tard, confrontées à leur sombre histoire commune...

In the summer of 1995, two vulnerable teenage girls are accused of murdering their schoolteacher. For seventeen years, the two girls go their separate ways, Poppy having been charged with the murder. Fast-forward to modern day. Happily married mother Serena is now back in the same seaside town for the first time as she cares for her dying mother Rachel. Poppy is living in quite different circumstances. Having served seventeen years for a crime she still insists she didn’t commit, she has only one thing on her mind… the truth. And if she didn’t kill Marcus, then who did?