Okay, looking at previous comments, I obviously do not share the opinions of other readers. I will now explain my rating. But before I do that, I will say the author's character development was excellent, her description of events, the environment was perfect to the point I actually believed I was in the places she described.
And I suppose that was my problem with this book. I felt totally and completely emotionally drained after reading "The Space Between Us." I am one of those people who typically goes to the movies, hoping to escape the realities of life, just for a little while. Usually, I read for the same reason, at least when I read fiction. If I want reality, then I read non-fiction.
I felt compelled to finish reading Umrigar's "Space Between Us," because I felt sure I knew how the book would end. I was wrong, thankfully, but it still left me unsatisfied and it only confirmed what I already knew - there are so many people living in this world who are so desperately poor and there is nothing that can be done about it. And that I find depressing. (And yes, I am for real and I am being totally serious.) Umrigar IS an excellent writer but I find her material too realistic, maybe that is my loss.