The Folk Keeper is a 1999 young adult fantasy book by Franny Billingsley.
Corinna is a Folk Keeper, charged with the important duty of pacifying The Fair Folk who live beneath Rhysbridge with offerings and protective spells so they won't wither the crops and curse the livestock. It is a difficult position to hold, and she has had to tell many lies to get it: about her gender, disguising herself as a boy called Corin; and about her powers, falsely claiming to be able to wield the mystical Power of the Last Word while hiding the other strange and seemingly supernatural talents she does possess. Everything changes for Corinna when she is recruited to become the new Folk Keeper of Marblehaugh Park: an estate built atop caves containing Folk far older and more powerful than any she has encountered before. But the greatest danger may come not from the Folk, but from the dark secrets hidden within the mansion itself.
This book contains examples of:
- Ambition Is Evil: Played with in Sir Edward. Its clear that Marblehaugh Park means everything to him, especially since we later learn Lord Merton had promised it to him, but he acts civil about it and it strikes one as a man very responsible for his belongings. Later we learn he goes as far as to sacrifice people to the Folk in order to keep it out of harm, and its serious enough about wanting to be his that he plans to kill Finian "in an accident" for it.
- Big Bad: Sir Edward, who is sacrificing people to the Folk and wants to get rid of Finian, and later Corinna, to be the new owner of Marblehaugh Park.
- Cute Clumsy Girl: Corinna. In her words, she can trip over everything and nothing.
- Death by Childbirth: Lady Rona, Lord Merton's first wife, died in childbirth; the baby died as well.
- Eyeless Face: Old Francis says of the beings beneath Marblehaugh Park, "the Folk are mostly mouth". Corinna later encounters one and sees that its face is indeed mostly taken up by a large mouth, with no eyes.
- The Fair Folk: Known as the Folk, they live underground and can cause crops to wither and animals to fall ill if not placated with offerings of food. They are repelled by cold iron, sea salt, and holy symbols.
- Hellhound: The Hill Hounds, vicious faerie dogs which specialize in hunting and killing.
- Holy Burns Evil: The Folk are repelled by the symbol of the cross and flinch at the invocation of the names of Saints.
- Horror Hunger: Corinna has always been able to subsist on very little food, but when she moves to Marblehaugh Park she begins craving fish — and she hungers for it not merely raw, but still-living. She initially repulsed by this craving, but eventually learns to accept it along with her other supernatural aspects.
- Human Sacrifice: When the Folk become unruly, one of the ways they can be calmed is through a human sacrifice; however, this is generally not considered to be a morally acceptable method, and Folk Keepers are employed to placate the Folk through other means. Sir Edward, however, has been making human sacrifices to the Folk in secret.
- Magic Hair: Corinna's hair is silver and grows two inches each day, requiring her to constantly cut it. When she stops cutting it, she learns that it also grants her the ability to sense her surroundings and the Power of the Last Word.
- Make It Look Like an Accident: Sir Edward tampers with the Windcuffer, expecting Finian to sail with it and perish in the sea. Being an experienced fisherman, Finian notices this, but instead believes Corinna was the one who did it.
- Masquerade Ball: At the Midsummer Festival, everyone dresses in costume. Corinna, as a nod to her Magic Hair, dresses as Samson.
- Mystical White Hair: Corinna has silvery white hair. The hair grows at a rapid pace of two inches per day, and she also possesses a number of other supernatural talents such as requiring hardly any food and always knowing the exact time.
- Puberty Superpower: Sealmaidens apparently come into their magical powers when they turn twelve years old.
- Rapid Hair Growth: One of Corinna's magical traits is that her hair grows two inches per night. She constantly trims it, both to prevent anyone learning about her magic and to disguise herself as a boy.
- Rapunzel Hair: Corinna's hair grows very rapidly; when she stops cutting it to pass as a boy, it soon reaches four feet in length.
- Room Full of Crazy: The Marblehaugh Park cellar has the words "Poor Rona" painstakingly carved into the stone over and over and over...
- Selkies and Wereseals: The sealmaidens, who have the form of sealions in the ocean but can take the shape of human women by taking off their fur coats.
- Shapeshifter Mode Lock: A sealmaiden whose fur skin is stolen is unable to shift shapes until she gets it back. Lady Rona was trapped in human form when Lord Merton burned her sealskin. Corinna's is also permanently damaged; she could use it once to transform to her seal form, but would afterwards be unable to ever change back to human.
- Shapeshifting Lover: A dark twist on the standard tale. A man stole a sealmaiden's fur coat and married her, but then tried to avert the usual second half of the tale by burning it to prevent her from ever finding it and returning to her kin. However, this resulted in the sealmaiden going insane and eventually dying.
- Sweet Polly Oliver: Corinna disguised herself as Corin to become a Keeper, since girls aren't usually allowed to take the position.
- Weakened by the Light: The Folk are repelled by light, including sunlight, starlight, and candlelight.
- Words Can Break My Bones: The Power of the Last Word is the ability to compose rhyming verse to which forces fae creatures such as the Folk to submit to the will of the speaker. Pre-composed or previously used poetry will not work; the Power of the Last Word can only be exercised through original and spontaneously inspired verse.