Harry Turtldove presents another book in the Crosstime Traffic series, which is set about 100 years in the future. It is a time in which we have learned to cross the barriers between alternative timelines. It has proven to be a boon for us as we are running out of resources on our own Earth. We send agents to other timelines to trade for materials we need.

In this most recent volume in the series, the Mendoza family has shifted into an alternate timeline that split off from theirs shortly before 1967. It was that year that brought about the Rain of Fire, or a nuclear war between the United States and the Soviet Union, devastating the world's culture. The resulting societies have reverted to a lifestyle not unlike the mid-1800s with the remnants of the good times that were all around them.

Liz Mendoza has joined her parents who have arrived in an area of what had previously been Los Angeles in order to provide them with access to the research library at UCLA. This is the first book in which the characters have crossed time for research rather than trade, and the Mendozas are a test case. They won a grant to come here in order to learn when exactly the timelines diverted ... and what led to the nuclear war. The Mendozas have settled into a Westside, formerly the West Side of the City, which has now become a small kingdom, like many of the other nearby neighborhoods of yesterday.

Liz is having trouble with her new life on the other side of time, where she must deal with greater inequality between the sexes and a society that seems to struggle to survive while continuing fighting between the various small countries that are rife in the former United States.

Things change a bit when Westside is attacked and conquered by Valley (without the, like, valley girls). She meets Dan, one of the soldiers who is bright yet held back by the world into which he was born. He becomes a bit besotted with her, and the two form what could have been a friendship in better circumstances.

Their interactions are made more challenging as Dan starts to notice some things that are just different about Liz and her family. He can't help but wonder if they are spies and so must act. This becomes particularly true when a Westside spy is captured fleeing their home.

It is a complex world, but seems quite realistic and well thought out. I have always thought that this series was better suited for young adults/teens because of its strong teen characters, but I think the publishers chickened out because they assumed that the need for knowledge about the true history and the deep concepts about considering the pros and cons of our own society would prove to be too much for the age group.

I have to admit that I was a little confused at the start of the book, but I think that was mostly due to my confusion about which state was which, particularly since I have no knowledge of LA. It also didn't healp that I am not a big fan of Cold War/1960s history so it didn't hold quite as much interest for me, but I thought the book was just as well made as the others in the series.