Version Control by Dexter Palmer, 495 pages
In the not-too-distant-future, physicist Philip Steiner working on building a time machine (sorry, "causality violation device"), though after dedicating several years to the project, it's still not working. Or at least it doesn't appear to be working. Version Control follows Philip's wife Rebecca, a depressed woman working for Lovability, an online matchmaking site. Rebecca and Philip's relationship has become strained since their son died in a car accident, with Philip throwing himself into his work and ignoring his grieving wife. But then Rebecca makes a choice that changes their lives, though she doesn't really realize it.
This is ostensibly a science fiction book, complete with a time machine, but really, it's an exploration of society, technology, and relationships. Heavy stuff, and it can sometimes get a little slow, especially if you're looking for a straightforward time-travel story (because this really isn't that at all). It's definitely provided some food for thought, and that's a good thing.