Serena Gorringe and Poppy Carlisle are two women who, as teenagers in the summer of 1995, were accused of killing their schoolteacher, with Poppy ultimately charged with the crime. For 17 years, they went their separate ways but now are forced to confront each other and their dark history. Now a happily married mother, Serena returns to town for the first time to care for her dying mother while Poppy, having served 17 years for a crime she insists she didn't commit, has just one thing on her mind - the truth. While the drama happens in the present, the events of the fateful summer of 1995 unfold through flashback sequences. Based on the Dorothy Koomson novel of the same name.