I shall start off by saying that, though I may be biased (once I decide to like an author, I generally “like” all of their things whether I literally do or not) The Scorpio Races is freaking amazing. I bought it for my Kindle and have reread it six times. And I doubt that's going to stop me from reading it again.
I love the storyline, I love the character development, the development of the relationships between the different characters, I even love the way the characters speak. Obsessive? Perhaps. Undue? Not even close.
Okay, okay, I know. Izzy, what's it ABOUT? Water horses (they're called something else in the book, but I don't want to misspell it). And racing. And a boy named Sean Kendrick and a girl named Puck Connolly. I don't want to give away too much, but here's what I can give you: Sean Kendrick is a four time winner of the Scorpio Races, and he rides Corr, a red water horse. Puck Connolly needs money fast (what better way than to win first prize in a death match?), and so she enters the races. On a normal island pony. And she's the first woman to enter the Races.
So the local boys are not happy about that one, except Mr. Kendrick, who makes a point of saying that if they try to take her out of the races, he'll be right there fighting with her.
Puck isn't a girlie girl, but she does have her moments of girlness, if that makes sense. There's no, “Oh, I got mud on my boots!” but there's a couple, “Well, he's cute and I'm in my muddy pants, crap.” And that's not so bad, considering.
Sean is an interesting character. I liked him a lot—unfortunately, I preferred being in his mind more than I liked being in Puck's, only because of the way he saw things, and the way he described things. I loved how much he loves Corr and how, after awhile, he started to have faith in Puck, which you can understand even without him flat out saying, “I think that Puck is going to have a chance to win the races and that's great and yet not so great at the same time”.
So, to sum it up: love the author, love the characters, love the storyline, love even the background characters. I highly recommend this book (and have already convinced a few of my friends to buy it). If you don't love it right away, read it again!!