Katherine and Matthew are destined to be born again and again, century after century. Each time, their presence changes history for the better, and each time, they fall hopelessly in love, only to be tragically separated. Spanning the Crimean War, the Siege of Carlisle and the near-future of 2019 and 2039, they find themselves sacrificing their lives to save the world. But why do they keep coming back? What else must they achieve before they can be left to live and love in peace? Maybe the next together will be different...