The Folk Keeper by Franny Billingsley

Years ago orphaned Corinna became Corin and started a new life as a Folk Keeper.  A Folk Keeper is important.  It is they who keep the Folk satisfied so they don't cause the crops to spoil and animals to sicken and die.  Everything changes when she is taken to be Folk Keeper at Marblehaugh Park, a manor house by the sea.  By the sea, Corinna is suddenly overwhelmed by powers she didn't know she had, and begins to piece together who she really is.

I loved Chime by Franny Billingsley but hadn't read anything else by her.  The Folk Keeper has some similarities with Chime, in particular the story twists and turns and keeps you guessing and then all comes together wonderfully in the end.  The Folk Keeper wasn't anywhere as confusing as Chime, which I always warn kids that they won't know what's going on for the first half but stick with it because it gets awesome.

Corinna decides to become a boy because she's suffered through life as a servant for others.  As a boy, she can be a Folk Keeper.  She has no training, of course, but she learns by listening and bribing others and becomes quite a good one.  Corinna has constructed for herself a very careful world devoid of emotions or attachments.  If someone does her wrong, she quickly and quietly gets revenge on them.  This is how she has survived alone for many years.  She is cold and vindictive and careful to make sure everyone respects the position she has so carefully built for herself.

Corinna is thrown when Sir Edward and Lady Alicia come asking for her by her true name, as she's gone as Corin for years.  She meets with Lady Alicia's husband, who speaks with her briefly before dying.  He wants to take her into his household.  She refuses, but agrees to come if she can stay Corin and be their Folk Keeper.  So Corinna, still as Corin, travels to the seaside where Marblehaugh Park is.

At Marblehaugh Park Corinna meets Lady Alicia's son, Finian.  Finian is heir to the estate, but all he wants to do is build boats and sail.  Corinna, for all her boasting and confidence in her abilities finds the Folk of Marblehaugh Park are nothing like anything she's experienced before.  They are ravenous and blood thirsty and Corinna is hardly able to hold them off.  In order to arm herself against them, she makes a deal with Finian.  He will tell her secrets of the estate she might be able to use to protect herself against the Folk, and she will give him convictions to be able to stand up to his mother and stay with the sea he loves.

Corinna has more people in her life then she ever had before.  She is actually beginning to care about people, which she doesn't like at all.  She is also experiencing strange things.  Why did she take to sailing so easily?  Why did swimming in the water feel so natural that one night?  What is Sir Edward hiding?  Why did Lady Alicia's husband want her here in the first place?  Who is the Lady Rona?

Just like Chime, everything comes together in the end.  Corinna pieces everything together and then must make a choice: stay with the people she perhaps has grown to love, or return to her true home.

Great middle grade fantasy with mystery, betrayal, and a little bit of romance.