Every December, Josie posts a letter from her home in London to the parents she lost on Christmas many years ago. But this year, her annual trip to the postbox is knocked off course by a bicycle collision with a stranger who will change the course of Josie's life. Aglow with new love, Josie thinks this might be the start of something special. Only for Max to disappear without saying goodbye. Over the course of the next year, Max and Josie will find that fate continues to bring them together in places they'd never expect. And it turns out, Max had every reason to leave and every reason to stay. But what does fate hold for Josie and Max as Christmas approaches again?