I had some reservations about the book when I first started and a lot of it stemmed from the fact that the first book I'd ever read from Cecelia, 
 P.S. I Love You 
 didn't exactly resonate with me as a reader. However, that might be because I'd watched the movie before getting my hands on the book - either way, a lot of factors played into my not being an overly big fan of that first one. But, Cecelia redeemed herself with this book. I loved it. It started off rather slow, and I was a little annoyed with Tamara's character, deeming her pretty whiny and incredibly self-absorbed, though with the way she grew up, it was a little understandable. 
 The Book of Tomorrow centers around Tamara Goodwin, a seventeen-year old girl (though at first, she believes she's only sixteen) whose life is rocked by the suicide of her father. Up until then, she and her parents had lived the life of luxury -- a magnificent mansion, with things that I can only dream of owning. Tamara's understandably spoiled rotten. She's gotten everything she's ever wanted - half the time, without her even asking for it. However, after her father's death, it's revealed that they had been in serious debt and after having their home and belongings taken away from them, she and her mother high tails it to the country, where they stay with their poor relations, Aunt Rosaleen and Uncle Arthur. Her mother has a hard time adjusting to life without her father, living almost in a vegetative state where her mind isn't all there and where she spends most of her time in her bedroom, asleep. 
 Behind her aunt and uncle's home, there is a castle ruin that she's completely drawn to and after a while (I really don't want to spoil TOO much here), she comes across a locked, blank diary that she's taken from a traveling library. There's nothing grand about it, until she goes to write in it and finds that there's already writing in it. Her writing. From the next day. Talking about things that haven't happened yet. At first, she believes it all to be a trick until the things that she'd written in the book starts to happen in the order that they were written. It's an interesting book and the major twist in the story actually had me sitting tensely in my chair for a good hour, completely oblivious to everything in my world except what was happening in the book. 
 I can't say much more without revealing everything that's happened in the book, but it is an incredible read and I absolutely loved every moment reading it. The magic behind the diary is never explained, however. I don't know how it even came to be, where it came from, or why it only works with Tamara and no one else. I wish Cecelia had found a way to explain the diary's origin, but evenso, it was so entertaining and I think this is one of those books that I'm going to end up reading again in the near future!