Ponyville Mysteries: Schoolhouse of Secrets

My Little Pony: Ponyville Mysteries: Schoolhouse of Secrets by "Penumbra Quill" (collective pen name of Michael Vogel and Nicole Dubuc) is the twenty-fifth book in a series of chapter books published by Little, Brown and Company and the first entry in the "Ponyville Mysteries" series.

In this book, the Cutie Mark Crusaders attempt to solve a strange mystery at the Ponyville Schoolhouse that appears to revolve around new student Lilymoon.

New ponies on the block
The story opens on an individual referred to in narration only as "The Pony" observing the village of Ponyville and expressing a particular interest in the Everfree Forest.

At the Ponyville Schoolhouse, the foals in Cheerilee's class make their way to the school to begin another day of classes. A number of foals are especially worked up after Twilight Sparkle and her friends recently stopped a manticore attack on the Friendship Express, and many ponies in town are expressing endless praise. Apple Bloom, starting to feel overshadowed by her heroic older sister Applejack, wonders if there is anything that the Cutie Mark Crusaders are meant to do beyond helping ponies with their cutie marks.

Diamond Tiara informs the Crusaders that a family of ponies recently moved into an old house on Horseshoe Hill and a filly from that family is going to be a new student in their class. The Crusaders decide to give the new filly a warm welcome and offer to show her around town. Once class begins, the school foals meet their new classmate: a unicorn filly named Lilymoon. However, the new filly does not smile, has a piercing and studious gaze, and mostly keeps silent, saying nothing except her name and that her family is originally from Trotsylvania.

A schoolhouse haunting
Lilymoon's behavior is off-putting to the rest of the foals, and they keep their distance from her throughout the school day. After school, the Crusaders discuss Lilymoon's strange behavior on their way home, and they spot her sneaking off into the Everfree Forest. They follow her inside, but after quickly losing track of her, they decide to find out what's going on the next day.

The next morning, when the Crusaders go to school, they find paint smeared all over the walls, books stacked up high on top of one another, and the classroom desks and chairs stuck to the ceiling. Furthermore, Lilymoon was apparently the first to arrive. As Cheerilee goes to get Starlight Glimmer or Zecora to fix this mess, the foals start to wonder who could have done this, and the blame quickly starts to shift onto Lilymoon.

When Pipsqueak accidentally knocks over one of the tall stacks of books, an invisible force in the classroom suddenly rushes toward him and carries him into the air. Using their Equestria Games flag-carrying routine, the Cutie Mark Crusaders save Pip, and the invisible force seems to disappear. The foals confront Lilymoon, who seemed focused on Pipsqueak the entire time, but Lilymoon denies all accusations and runs off. When Cheerilee returns and learns what happened, she announces that class is cancelled for the day and that the schoolhouse will be closed until they figure out what's going on.

The Crusaders' big mission
With the rest of the day free, the Crusaders head to Sweet Apple Acres, where Applejack, Big McIntosh, and Granny Smith are busy making baked goods from zap apples. When Applejack asks why the fillies aren't in school, the Crusaders explain what happened, making particular mention of Lilymoon and the house that her family moved into. When Granny explains the house's ominous reputation, Applejack considers rounding up her friends to investigate, but Apple Bloom insists that she and her fellow Crusaders can handle it.


 * Applejack: Well, of course I know that. I'm just worried about you is all.
 * Apple Bloom: Of course you're worried about me! You're the almight Applejack, hero of Equestria! And I'm just your little sister who can't do anything on her own!

After Apple Bloom's angry outburst, Sweetie Belle and Scootaloo find her sulking at Sugarcube Corner. Still feeling overshadowed by her older sister, Apple Bloom wants to prove that she and her friends aren't little fillies anymore and can handle the occasional crisis on their own. Sweetie Belle and Scootaloo, feeling equally overshadowed by Rarity and Rainbow Dash respectively, sympathize with Apple Bloom and offer to help. They decide to head back to where everything started: the Everfree Forest—where Lilymoon happens to be sneaking off to again.

Fracas in the forest
Apple Bloom, Sweetie Belle, and Scootaloo follow Lilymoon into an unfamilar area of the forest, taking extra care not to be discovered. They find her in a small clearing using her magic to stack rocks on top of one another, just like the books at the schoolhouse. Accepting this as proof of Lilymoon's guilt, Apple Bloom steps out to confronts her, but vines from the trees suddenly ensnare Sweetie Belle and Scootaloo and pull them up into the tree branches.

Apple Bloom tries bucking the tree to free her friends, but the vines suddenly grab her as well. Lilymoon pokes at the tree's trunk with her hooves, causing the vines to pull tighter. Apple Bloom pleads for her to stop, but Lilymoon doesn't listen and soon runs away. As the fillies struggle to break free and cry out for help, the vines eventually loosen enough for them to get untangled, and the Crusaders decide to confront Lilymoon once and for all at her hilltop house.

The house on Horseshoe Hill
At Lilymoon's creepy-looking house on top of Horseshoe Hill, the Cutie Mark Crusaders look through the window and see two unicorn ponies who have the same coat and mane colors as Lilymoon brewing potions in a a large cauldron. All of a sudden, they find themselves surrounded by fog and stuck to the ground; another resident of the house—an elderly unicorn named Auntie Eclipse—has discovered and trapped them for snooping around.

Before Eclipse can ask why the Crusaders are snooping around the house, an unexpected explosion from inside distracts Eclipse long enough for the Crusaders to escape. Unfortunately, they are soon cornered by another, younger unicorn mare named Ambermoon as well as the two potion-brewing unicorns from earlier. As the unicorns converge around the intruding fillies, Lilymoon appears and reveals that they are her classmates, and the unicorns let them go. Apologizing for the confusion, the unicorns introduce themselves as Lilymoon's family: her father Blue Moon, her mother Lumi Nation, her older sister Ambermoon, and her great aunt Eclipse. The Crusaders are further surprised to learn that, just like them, Lilymoon and her family all have matching cutie marks.

In Auntie Eclipse's library, the Crusaders ask Lilymoon directly about what happened at the schoolhouse and the Everfree Forest. Lilymoon explains that she didn't attack them—she saved them from a poison joke tree by tickling its ticklish spot. However, while she denies using magic on the schoolhouse, she does admit having some involvement in the incident. She explains that the school is currently occupied by a bogle, a rare and invisible creature, and that she accidentally brought it to Ponyville by disturbing its nest in the forest. She had tried to rebuild the bogle's nest, which the Crusaders caught her doing earlier, but it refuses to leave the comfort of the schoolhouse.

The Crusaders suggest asking Lilymoon's family for help, but Lilymoon refuses, saying her family members are experts in science, botany, magic, and potions and she doesn't want to be seen as a disappointment to them. The Crusaders sympathize with Lilymoon, also having ponies to which they look up and want to prove themselves, and offer her their friendship and assistance. Together, they come up with a plan to get rid of the bogle.

The bogle debacle
Apple Bloom, Sweetie Belle, Scootaloo, and Lilymoon sneak into the Ponyville Schoolhouse after dark and hear the invisible bogle snoring. Apple Bloom and Sweetie Belle wake the bogle up by disturbing its nest in the classroom, and Scootaloo and Lilymoon cover it in paint to make it visible. Enraged by having its nest and slumber disturbed, the bogle chases after the fillies. They lead it toward the site of its original nest in the Everfree Forest, which they have decorated with warm, glowing lanterns and fabrics and cloths from Carousel Boutique.

The fillies take shelter from the bogle in the treetops, and the creature appears pleased with its refurbished nest. However, with the bogle now sleeping directly under them, they are unable to leave the forest until sunrise. When the fillies are finally able to get away safely the next morning, they are confronted by both Apple Bloom and Lilymoon's worried families. Lilymoon confesses and takes responsibility for everything that happened. While Lilymoon's parents are impressed that their daughter encountered a bogle without gettng hurt, they apologize to the Apples for any problems she caused. Lilymoon and her family leave to return home, and Lilymoon gives the Crusaders one last look of gratitude.

When Applejack asks Apple Bloom why she didn't come to her for help in dealing with the bogle, Apple Bloom says she wanted to prove that she can be just as brave as her big sister. Applejack tells Apple Bloom that she already thinks she's brave and she is always going to want to help her, but it doesn't mean she thinks Apple Bloom can't help herself. The two sisters make amends, and the Crusaders promise not to go looking for danger and causing unnecessary trouble—especially the imminent trouble they'll be in with Rarity for stealing fabrics from her boutique.

The story ends with "The Pony" from the prologue observing the Everfree Forest with concern and expressing deep interest in the Cutie Mark Crusaders.

Quotes

 * Apple Bloom: It just seems like there's gotta be something more out there for us to do.
 * Sweetie Belle: We've been helping other ponies figure out their cutie marks. After all, we've had plenty of experience with that!
 * Apple Bloom: I know, and don't get me wrong. I love that our cutie marks are all about helpin' other ponies with their cutie marks. But don't y'all wish it was a bit more... exciting sometimes?
 * Sweetie Belle: Exciting sounds like another word for dangerous.


 * Diamond Tiara: We're all trying our best to be welcoming, but if a pony doesn't want to be friends with anypony else, far be it from me to force her!


 * Apple Bloom: You think maybe she just misses her friends back home?
 * Scootaloo: Lilymoon? With an attitude like that, what makes you think she has any friends back home?
 * Sweetie Belle: She gave me the creeps. The way she stared at us? Spooky.
 * Apple Bloom: Maybe things are different in Trotsylvania. Maybe starin' at ponies is the way they say hello?


 * Twist: Thith definitely theemth like more than jutht a prank.


 * Silver Spoon: Well, if nopony else is going to point out the obvious, I will. Nothing like this has ever happened before, so what's the big difference now? Would you like to tell us anything, Lilymoon?
 * Lilymoon: I have nothing to say to any of you.
 * Apple Bloom: Now, everypony, just take a breath. Lilymoon, nopony is sayin' this is your fault or nothin'—
 * Diamond Tiara: I think that's exactly what we're saying. You don't think it's a little bit odd that Lilymoon shows up, and the next thing you know, all this happens?


 * Granny Smith: It's that new family up on Horseshoe Hill! That house has been empty for more moons than I care to count. Somethin' strange about it.


 * Apple Bloom: When Applejack was my age, she had already defeated Nightmare Moon!
 * Scootaloo: Actually, I don’t think they were quite this young when—


 * Sweetie Belle: A giant tree is pulling us to our doom and nopony even knows we're out here! How could it get any worse?!


 * Apple Bloom: Wh-who's there? What do you want?
 * Auntie Eclipse: What do I want? I'm not the one snooping into other ponies' business, now, am I? Auntie Eclipse thinks you should answer your own question. What do you want?


 * Lilymoon: My father is an expert on reading the stars. Astrology, science, magic. My mother spent her life studying the plants of Equestria. She can recognize every leaf, root, branch, and berry that exists, especially the ones with magical properties. My sister is a natural with potions and spells, and Auntie Eclipse... well... she knows everything about anything that has ever happened in Equestria.
 * Sweetie Belle: They sound smart! Why don't we want to ask them how to get rid of the bogle again?
 * Lilymoon: I can hear exactly what they would say. Oh, Lilymoon, you shouldn't have gone out alone. Oh, Lilymoon, don't mess with things you don't understand. Oh, Lilymoon, why can't you be brilliant and amazing just like the rest of us? Oh, Lilymoon, why are you such a disappointment?


 * Lilymoon: Why would you help me?
 * Apple Bloom: That's what friends do.
 * Lilymoon: I don't have friends.
 * Scootaloo: Well, with that attitude, I can see why.


 * Sweetie Belle: As my sister would say, you can't argue with good taste.


 * Lilymoon: I couldn't have done it without... my friends.


 * Applejack: You are one of the bravest ponies I've ever met in my life... and I know some pretty brave ponies. But you're also my little sister. I'm always gonna worry about you, and I'm always gonna want to help you. It don't mean I think you can't help yourself. It's just what big sisters do. Got it?
 * Apple Bloom: You really think I'm brave?
 * Applejack: Of course I do!
 * Apple Bloom: Well, then just stop bein' so amazing all the time, and I won't have to work so hard to keep up.


 * Rarity: What in Equestria happened to my fabrics?!
 * Sweetie Belle: We are in so much trouble.