Also added to my list for a long geo-trip, this one wasn't "time travel" but just a strong sci-fi recommendation. It was also a lot shorter than the last one, so it was also finishable in the same trip. 

This one was weird. I really was getting into it, and thinking the story could go in a really great direction... And then about 2/3 - 3/4 of the way through it jumped the rails and went straight into sci-fi horror with monsters and gory deaths. At this point I just wanted to finish and be done. 

And then... At the end, they threw in a twist, that left me wanting a sequel. Argh! Though knowing the style this book went towards, maybe I DON'T want to read a sequel...