This novel has an interesting premise in that these time travelers work for a corporation hundreds of years in the future that goes back in time and steals resources, whether it be machinery or trees. The future Earth is almost dead, with a blight that has killed all life in the oceans. Mankind exists among the planets, barely surviving, and as the years go by it gets more difficult.
But one traveler falls in love with a woman he meets in the past and brings her back to his future, which is breaking the first "time law" that they have. If they bring someone back from the past it will supposedly wreak havoc with the current reality-and that one displaced person will die horribly in a matter of days. Only that never happens. Has he-and all the other Salvagers been lied to? And if so, why?
Although this is a bit of a downer, it is a good book, sort of along the lines of BLADE RUNNER crossed with the movie LOOPER.