A time travel novel, where they bring back some people from previous centuries, and if they survive, try to integrate them into the modern society. Why? That's classified and for the managers of the programme to know. Until things start going wrong and the bridge falls in love with her time traveller. But then things really go wrong and different timelines get mixed up, and all in all, the future is just trying to change the past to stop global catastrophies and famine and all that sort. So quite confusing overall, and including this time machine which no-one really knows exactly how or why it works, but it all comes to a nice ending where not many people are dead after all.