When Lydia breaks up with her long-term boyfriend, she flees to a villa in Spain. There she's surprised to bump into her old childhood friend, Dan. Years before the pair had made a pact: if they were still single when they turned thirty, they would get married. Lydia and Dan's friendship now rekindled, it doesn't take long before they fall into a holiday romance. Giddily in love, the couple realise there is nothing stopping them from fulfilling their romantic pact. But how much do they really know about each other?