Rating: 4.5 StarsAll Our Yesterdays is the book I've dreamt about, for nearly two years now. Ever since I began watching Doctor Who, I've been a huge fan of time travel. Sadly, however, none of the time travel books out there seemed truly remarkable and after watching episodes that blew my mind (thank you, Steven Moffat!), I knew that it would take a lot for a novel about time travel to truly impress me. Thus, it was a thrilling - and by no means expected - surprise to find that All Our Yesterdays was every bit as brilliant as rumored. Of course, this isn't a perfect debut, but it's pretty darn close. All Our Yesterdays can be a bit confusing, at least when it comes to the plot, but I firmly believe that this novel is experienced at its best when little is truly known about it. Instead, what you do need to really know about this tale is that it revolves around the friendship of three teenagers, one of whom goes on to create a time machine and slowly become consumed by his ambition and greed. Thus, in order to save the world from the destruction they've witnessed in the future, the other two - Em (or Marina) and Finn - travel back in time to change the future. After dozens of unsuccessful attempts, they've both arrived at the same conclusion: in order for the future to be protected, they must kill their friend...before he turns into the monster he will eventually become.What Terrill excels at with her debut are her characters. Each and every character is complicated and three-dimensional. Nothing about this story is black-and-white and although it seems like a simple thing to know right from wrong, Terrill goes on to show us just how ambiguous morality can be. Not only are her time travel elements intelligent and believable, but they also work together with the plot seamlessly. Em and Finn, now much older than their teenage selves, carry the burden of the future with them, but also that of knowing their friend before he changed. Thus, to kill him before the transformation is complete is much harder than they anticipated. Furthermore, even though we are given glimpses into the future, we also know the past. As Em and Finn know their friend, we grow to know him too, and despite knowing what he becomes, we cannot help but like him for who he is now. Terrill truly opens a can of worms with the questions she forces readers to truly ponder and I love a book that can make me think and question what I myself to believe cold, hard facts. Furthermore, the plot of this novel is breath-taking. It is doubtful that you will even have time to breathe; I know I forgot to on more than one occasion. Moreover, I found that the pacing was perfect, so by the time everything came together by the end, I was practically falling to the floor off my seat in excitement and curiosity. And yet, perhaps because of the brilliance of so many concepts, Terrill's faults are also rather egregious. Most notably, perhaps, is that it is ever-so-slightly difficult to truly enjoy her characterization until much later in the novel. Marina, the younger version of Em, is a rich - there's no other word - brat. As the story progresses, though, it becomes clear that the transformation of these characters from their younger, innocent selves to their older, hardened selves is remarkable. And yet, it also reduces the emotional impact the characters have. Furthermore, many of the events in this novel are grossly simplified by the presence of money. With novels like The Raven Boys, the economic status of her characters seems a natural and ingrained factor. With All Our Yesterdays, however, it truly felt convenient. Moreover, I found that minority characters - such as a Mexican housekeeper - were sadly stereotyped. As I mentioned, Terrill's attention to detail in so many areas grew to become a fault as the few issues she didn't focus on became small flaws in her otherwise brilliant debut. Nevertheless, All Our Yesterdays isn't a book to miss out on. It's fast-paced, intelligent, romantic (oh, how you will swoon!) and - most of all - thought-provoking. I'm not sure there's anything more I could possibly ask for.