Time City — built far in the future on a patch of space outside time — holds the formidable task of overseeing history, yet it's starting to decay, crumble .... What does that say for the future of the world ... for the past ... for the present? Two Time City boys, determined to save it all, think they have the answer in Vivian Smith, a young Twenty Century girl whom they pluck from a British train station at the start of World War II. But not only have they broken every rule in the book by traveling back in time — they have the wrong person! Unable to return safely, Vivian's only choice is to help the boys restore Time City or risk being stuck outside time forever...