The Tourist

If you really enjoy Christopher Priest, you may very well enjoy this one

In a post-apocalyptic future which has rebounded somewhat in terms of technology, privileged citizens can experience the 21st century firsthand through portals run by time-travel tourism companies. A tour guide is just biding his time until he is able to retire and enjoy life as he really wants it. But then, on what should have been an ordinary afternoon shopping trip, one of his tourists disappears, and he is obligated to try to find her.

Like Christopher Priest's books, this novel has some really interesting premises and worldbuilding, and the plot is pretty interesting--right up until about 75% of the way in, when it totally loses its way. There are all sorts of intriguing starts to things which never get finished, and the book basically just trails off with none of the questions and mysteries it raises ever getting answered or solved. If you really enjoy Priest, you may very well enjoy this one. I found it supremely unsatisfying, and I wish that the author had chosen to have more of a real ending to the book.