This review and others are posted at Read, Rinse, Repeat.
The first thing that I'm going to praise in Parallel is the character of Caitlin, Abby's best friend. How often do we have the best friend character who is there to deliver a bit of snark and not much else? In Parallel, Miller gives Caitlin both the physical, mental, and emotional characteristics more typically seen in the main character. I've wondered if there is some writers' guideline that dictates "the best friend" must always stay in the background. If so, Miller violates those guidelines, and the story is better as a result. Caitlin is beautiful and brainy, and completely supportive of the bizarre situation in which Abby finds herself. She throws herself into helping Abby untangle the mystery of her parallel life. Although it might have been a touch less interesting, since Abby was the one aware of her parallel experience, I think a great story could have been made from Caitlin's POV. Maybe a novella? Hint, hint, Ms. Miller. :)
Since Caitlin is so well-written, it should not be surprising that Abby is a wonderful main character. She's good, but not perfect. She's got her life mostly figured out, but really, at seventeen, what do most of us know? Caitlin and Abby have a pretty vicious fight in the middle of the cafeteria. Both say cruel things. If you've ever had a fight with your BFF, this scene will hit hard, Clearly, tension was building up in both girls, and with just a little kindling, it exploded. When guys fight, they can throw punches, cool down, and be friends a few days later. Girls, however, know how to cut deeply with words, and sometimes it can take much longer or be impossible to recover from those wounds.
And now I must confess: at times, I was completely confused; Are we in the "real" world or the parallel world? Which characters have experienced and remembered which events, and which have never happened? I was lost at times, and I relied on Abby's narration to eventually help me sort it out. This worked until the next chapter which jump worlds and times again, and I was lost again. I must mention that I'm a very literal, logical thinker, and I don't process the abstract as well. I think the majority of readers will be able to keep up, so don't let my experience scare you off.
So...I haven't mentioned the guys yet. This seems, on its surface, like a triangle, but it's truly a square because it involves "real" Abby and "parallel" Abby and two guys who appeal to the Abby's for very different reasons. There are some great spoiler-y stories here, and of course, I a'int goin' there. Read and enjoy, my friends. :)
The ending was lovely, surprising, and just perfectly tied up the story's loose ends, even when we were thrown for a last minute loop, where I wanted to scream, "NOOOOO!" I know others will find it predictable, but I'm not on of them. Even if I was, that wouldn't detract from the emotions I felt during the final pages, because even after my howl, Miller wasn't quite finished yet, and she threw readers a nice, juicy bone.
Note - I was provided with an ARC by the publisher with the request for an honest review.