When Rosa and Bee get together in the run-up to Bee's wedding, they reminisce about the holiday they took together as teenagers to the beautiful Greek island of Paros. They remember the sandy coves and the guest house in the converted windmill where they stayed with their friend Iona. As memories of that holiday resurface, they are forced to confront the turns their lives have taken—and the guilt they feel about letting Iona slip away from them. When they learn that the windmill guest house is going bust they form a plan: why not go back to the island and take it over themselves? And so begins a life-changing journey—because it turns out that reliving their teenage dreams isn't that easy.