In the Serpent's Coils, by Tiffany Trent, is the first book in her Hallowmere series.
At age fifteen, Corrine wakes up to find herself an orphan in the care of her uncle. Told that her mother took ill and died, she finds herself kept virtual prisoner by her uncle and his servants, her every move watched and forbidden from looking at her mother's trunk*. The only freedom she has is in her dreams, where she sees faries who warn her, and in the garden, where she finds that there is something inhabiting the hawthorn bush. After agreeing to a deal with the inhabitants of the hawthorn bush, Corrine's uncle discovers what she has been up to and sends her away to Falston Manor, a reform school.
Once there, Corrine finds that her life was actually better at Uncle William's. The girls are cruel, the teachers worse, and every night Corrine is locked inside her room in the attic, where she spends her nights dreaming of horrible things that have, or might have, or might one day, happen. Also, two girls have disappeared from Falston, and Corrine is haunted at night with visions of what happened to them.
Slowly though, Corrine adapts to life at Falston. She begins to make friends with Christina and Ilona, two other girls there; Miss Brown, the headmistress, isn't so horrible; and Corrine discovers, hidden in the library, letters from a monk, Angus, to a nun, Beatrice, detailing their forbidden love.** She finds several more of these letters and learns that Angus has sided himself with the fey, while Beatrice is still hiding herself within the abbey.
Still, it isn't until Corrine discovers that the teachers (and the priest) at Falston are witches, in the service of the Captain, that she takes action. Learning that the Captain is the one stealing the girls for use in blood sacrifices, Corrine agrees to help the fey stop the witches.
However, what Corrine doesn't know is that with her decision, she's just made everything worse.
(here there be spoilers...and for book two, too)
As I said, this is the first book in the Hallowmere series, a new take on the fey. I liked Trent's world; how she split the fey into two distinct groups, the Unhallowed who seek to destroy humans, and the Hallowed who are there as protectors. Then, there are the witches, who...well, it seems like the witches are against the fey, except for the witch-fey and I don't know who's side she was on. (Or is on?) Corrine gets thrust into the middle of it all and learns that her family has been involved in this battle for decades.
I don't want to give too much away, but there are several different plot threads running through this novel. The mysterious Captain-in the service of the Witch-who follows Corrine around (I think he's going to turn out to be her presumed-dead father); the Witch, who isn't a witch (i.e., like Corrine's teachers); Rory, who seems to see the same things Corrine does; Corrine's missing locket (no one knows when that disappeared, but Corrine knows she had it before she fell ill); the witches and their secrets; and the Unhallowed, who seem to have a disturbing interest in Corrine. Most of these threads are carried over into book two (which I loved, I only liked this one), leaving us with the same questions that Corrine has.
Who is she? Who was her mother? Why is everyone keeping things from her? What happened to her father? Why do the Unhallowed fey have such an interest in her? What does the little silver mark in her eye mean?
*Inside her mother's trunk were several things that, as a child, Corrine didn't understand. But, one of the things inside there was a picture of a beautiful young woman, wearing the same iron cross as Corrine's mother had, a wicked smile, and feline-shaped eyes.
**I think that the mysterious Mary-Rose child is the same one whose picture Corrine found in her mother's trunk. The monk's letters about Mary-Rose hint at her mysterious background and how they've bound her from ever knowing what she is. Corrine's mother wore the iron cross to protect herself from her abilities. It would make sense to put that same cross on someone (without telling them what it can do) if you wanted to shield them. I also think that Mary-Rose is Angus*** and Beatrice's child...although those hints are really in the second book.
***Except, it's not going to be Angus's child, is it? (We get hints of that in book two, but I'll be it comes out in book three.) I really like the Unhallowed fey; they're tricksy.