In a dystopian future where the "Republic of London" has been walled off from the rest of the world for 250 years by an electronic barrier, Vice President Melville Wilson believes the time for reunification has come. But when he's killed in a train accident, authorities suspect foul play and believe the Outsiders are responsible. Determined to learn the truth, his daughter, Melinda, sneaks her way through the barrier, for the first time leaving the protection of the Republic to travel through the world outside - a world that holds both danger and promise.