With the rising of Celestia’s glorious sun and the obnoxious crowing of a nearby rooster, a cream-colored filly with a red mane awoke in her bed on a warm midsummer morning. She pulled off her nightcap and groggily arose to start her day. After she combed her mane, brushed her teeth, and straightened her tail, she stared in the mirror for a moment, thinking about what she had to do at school today. As a thought crossed her mind, her eyes widened, as did her smile.

Friday! Today was the day!

She squealed in delight and raced down the hall, where she accidentally crashed into her older sister Applejack.

“Uh-oh,” she moaned, “Ah’m sorry, sis! Didn’t see ya there.”

“It’s alright, Apple Bloom,” the orange mare replied, wincing in slight pain. “Just be careful next time. Where’s tha fire, sugarcube?” she asked, her tone switching from calm to curious.

“Ah forgot ‘bout today! Miss Cheerilee said we were having a guest speaker in class today!”

“Well, ya better git goin’ then,” she replied. “Grab an apple or two on yer way out!”

“Will do!” she called as she raced into the kitchen and dropped three apples into her saddlebag, along with her lunch. An elderly green mare was seated at the dining room table.

“Well, somepony’s in a rush this mornin’!” she said.

“Sorry, Granny Smith, but I don’t wanna be late for school today! Ah gotta go!” she admitted hurriedly as she slung her bag over her back. “Ah love ya!” She gave her grandmother a hug.

“Love ya too, Applejack,” she said back.

“Granny!” the filly protested sweetly, “I’m Apple Bloom! Applejack is still upstairs.”

“Oh…right. Well, off with ya!”

“Bye!” she said as she raced out the door, shouting another farewell to Big Macintosh, who was busy bucking apples.

“Eeyup,” he replied unsteadily.

As the filly raced off to school, she never saw her big brother’s face turn a revolting shade of green.

“Good morning, class!” a fuchsia mare greeted.

“Good morning, Miss Cheerilee!” they called back.

“Well, class, as you know, we’ve been working on our times tables up to 8x8, and the time has come for you to take a test…”

The class groaned at the idea.

“But if everypony does well,” Cheerilee continued, “I’ll have a very special surprise for all of you after lunch!”

“YAY!” they cheered.

“But before that, we have to get through this,” She passed out the test sheets to the class, who groaned once more. “Everypony grab a pencil and begin. Set your worksheets on my desk when you’re finished.”

The test was an innocent set of multiplication problems. Just figure out the problems and write down the answers. As usual, Silver Spoon and Diamond Tiara finished first, both looking as snooty and stuck up as ever. Apple Bloom eyed her paper nervously at first, but then she remembered all the time that she, Sweetie Belle, and Scootaloo had spent studying with Impact Hammer down at the Broken Wing Workshop, and the answers began to flow from her head like water. 5 x 3…15, 4 x 7…28, 7 x 8…56. She was done in about twenty minutes and finished at the same time as her fellow Crusaders did.

As she passed in her test and returned to her desk, Apple Bloom breathed a sigh of relief. The worst part of her day was behind her. Now she could look forward to the rest of it…

That afternoon…

“Follow me, everypony!” Cheerilee called to her class, leading them out into the meadow behind the schoolhouse. She led them to a large clearing in the center of the grassy field. Once everypony was seated, a burst of white magic brought forth a silver pony with crimson eyes and a blue-and-black striped mane. Her left wing and left foreleg shimmered in the afternoon sun, reflecting much more light than normal wings and legs were meant to.

Impact Hammer, the alicorn who ran the Broken Wing Workshop, the new repair center in the heart of Ponyville, was standing before them wearing a lab coat and safety glasses.

“Hi, everypony!” she said with a smile.

“Hi, Miss Impact!” the class replied.

“Impact has prepared a science demonstration for us,” Cheerilee explained, turning their attention to Impact as she sat down beside her students. “They're all yours.”

“Before we begin, I need each of you to put one of these on.” She picked up a box with her magical aura and passed it around to the class. It was filled with foal-sized pairs of safety glasses, and each pony took a pair and placed it over their eyes. “Safety first, everypony!” she said with a smile as she levitated an adult-size pair toward the schoolmare. “You too, Cheerilee.” The teacher nodded gratefully and Impact gently guided the protective eyewear onto her face.

“Today, we’re going to talk about the science of matter,” Impact said as she began her lesson. “Does anypony know what matter is?” she asked.

Silver Spoon raised her hoof apprehensively.

“Isn’t matter just…stuff?” she asked.

“Actually, yes!” Impact explained, “Matter is the substance from which all physical objects consist. It’s in everything from the grass and the trees to you and me! Matter comes in three forms on our planet, known as states of matter. Can anypony name one?”

An orange hoof shot into the air.

“Gases!” Scootaloo cried.

“Exactly!” she said as she held up two balloons in her magical aura, one red and one blue, “Gases have neither definite shape nor definite volume.” She let the balloons go. The red one flew off into the sky, but the blue one sank to the earth like a rock. “Those balloons were the exact same size and shape, but behaved completely differently! Can anypony tell me why?”

It seemed like nopony would figure it out until Apple Bloom raised her hoof.

“Yes, Apple Bloom?”

She scratched her head for a moment. “Ah think tha balloons are filled with different gases.”

“That's absolutely correct!” Impact said with a smile, “The red balloon was filled with a gas called helium, which is lighter than air, so it rises. The blue balloon was filled with a gas known as xenon, which is heavier than air.”

“So that’s why tha blue one sank!” the yellow filly realized, her eyes alight with epiphany.

“Exactly! What’s another state of matter?”

Diamond Tiara’s hoof rose.

“Liquids.” she spoke with an elegant tone.

“Well done!” Impact replied as she turned the class’ attention to a jar of used cooking oil. “Liquids have a definite volume, but no definite shape. The shape of a liquid conforms to the container it’s placed in.” She raised it above her head and dumped it out, letting her magic condense it into a floating sphere. The oil began to flow, guided by her will into a hypnotizing show of shapes and waves, rippling and twisting in all directions, until it rose into the air and exploded, dispersing into a fine mist. With a flick of her horn, the droplets recombined into a single laminar stream and flowed back into the jar, much to the students' amazement.

“And the third state of matter?” she asked as she twisted the jar’s lid closed.

Sweetie Belle raised her hoof.

“Solids?” she asked.

“Very good, Sweetie Belle!” she praised, “All solids have a definite shape and a definite volume.” She paused for a moment as brought forth a wooden table with her magic. “I actually found this table in the basement of my house when I first moved in, and I just can’t stand to look at it anymore, so…I’ve decided to destroy it!” She looked toward the class, who were now thoroughly intrigued. “How do you think I should put this eyesore out of its misery? With a sledgehammer? With a hatchet?” She cast a devilish smile. “Or…with a chainsaw?”

Several colts sat bolt upright. They immediately recognized the name of the signature weapon from the Equestria-famous zompony apocalypse comic book saga The Trotting Dead.

“CHAINSAW! CHAINSAW! CHAINSAW!” roared the cheering crowd, mostly from the colts, Scootaloo, and most surprisingly, Miss Cheerilee!

“Well…can’t argue with that!” she said with a smile as her horn glowed and her bionic hoof transformed. The outer metal panels slid back to reveal the intimidating bladed weapon. She reared back and let out a loud battle cry as the chainsaw came to life with a powerful roar, then swung forward, letting the razor-sharp teeth bite into the ugly table and cleave it in two. As the pieces fell to the earth, the class roared with approval. Impact turned off her chainsaw and let it disappear underneath the outer shell of her mechanical hoof, which regained its default structure.

“Well!” she said, wiping the sweat from her brow, “That was fun…OH! That reminds me! Some substances can change from one state of matter to another. These are called phase changes, and one substance in particular on this planet can exist in all three states, depending on the temperature. Can anypony tell me what I’m talking about?”

“WATER!”

“Absolutely right.” She teleported an ice cube tray, a drinking glass, and a teapot before her. “Because of its low melting and boiling points, water can freeze into solid ice, melt back into liquid water, then boil into steam. As you can see, the three states of matter are everywhere, either as solids, liquids, or gases. From the foods you eat and drink, to the air you breathe, to the planet beneath your feet. Isn’t that fascinating?”

The foals nodded in agreement.

“But…I’ll let you in on a little secret.” She leaned in close to whisper to the class. “Did you know that a fourth state of matter exists?”

The class began to murmur anxiously.

“Miss Impact?” Apple Bloom said nervously, “Ah thought ya said there were only three states of matter.”

“Yes. On Earth. There are three states of matter found on Earth.” She cast a spell and her bionic hoof transformed again, exposing a dark grey open-ended cylinder. “While it isn’t found naturally on our planet, it can be created to a certain extent. It goes beyond our planet, beyond our solar system, beyond our galaxy. This fourth state of matter makes up 99% of our universe.” She closed her eyes and began to focus. Her mane and tail began to lightly crackle and spark with electricity. Eventually, a blue sphere of energy materialized in the end of the device. “This is the fourth state of matter, and it’s called plasma.” she explained as she opened her eyes.

The class sighed with astonishment at the sight of the swirling blue energy ball.

“Plasma is created when a gas is heated to point that it becomes ionized, where the atoms don’t same the same number of electrons as protons…”

“Remember, Impact!” Cheerilee warned. “These are foals you’re instructing.”

“Oh…yeah…right,” Impact said with a slight blush. “This is my Plasma Cannon,” she said to the class. “It allows me to channel my natural electricity into bursts of energy. When the gases inside get really, really hot, I can launch them like this. Glasses on, everypony!” she quickly warned.

She turned and eyed a large bulls-eye tacked to a tree, one of several temporary targets she’d set up all around the schoolyard. Striking a tripod stance, she lined up her target, aimed and fired. The blue energy ball shot outward and left a charred black hole in the paper…and the tree. She spun around, faced the jungle gym, and took out a row of targets tied to the bars with six rapid-fire blasts.

Over and over, she spun, flipped, and fired, blasting every target in the school yard, eliciting louder and louder cheers from the class with every target she hit, until she blasted her final target: a pinecone perched atop the schoolhouse roof. The schoolyard erupted with applause.

“Very impressive, Impact!” Cheerilee said, awestruck.

“Yeah!” Scootaloo cheered, “I’ve never seen Rainbow Dash do anything as cool as that before!”

“Where’d ya learn ta shoot like that?” Apple Bloom wondered.

“Practice, practice, practice. Every single day,” Impact said confidently. “I’m pretty sure I could hit just about anything with this thing.”

“Anything?” called a voice from behind.

Out of nowhere, a majestic white alicorn emerged from behind a tree. Everypony stopped in their tracks and knelt to the ground, praising their illustrious princess.

“Good afternoon, Princess Celestia!” everypony greeted in unison.

“Good afternoon, my little ponies!” the solar matriarch replied. “Such a wonderful day to be outside, isn’t it?”

“Yes. Yes it is,” Cheerilee agreed. “What brings you to Ponyville so...unexpectedly?”

“I suddenly need a reason to consort with my subjects?” Celestia replied with a strict tone, casting a fierce glare toward the fuchsia mare. As the schoolmare’s eyes widened in fear, the princess’ gaze softened and she erupted into a fit of giggles. “I jest, Cheerilee, I jest,” she assured with a smile, “My personal chef had a funeral to attend this afternoon, so I decided to go out for lunch today.” Using her magic, she produced an apple from her bag and took a big CHOMP out of it. “Mmm… delicious!” she cooed blissfully, which prompted a beaming grin from Apple Bloom. “It also gave me the perfect opportunity to visit my daughter.” She cast a wink and a smile at Impact, who blushed at the unexpected attention.

It had been six months since Celestia publically revealed Impact’s status as her adoptive daughter. Needless to say, most of Equestria was shocked and appalled by the news, but when the two explained the terrible accident and the subsequent events that brought them together, their hearts softened and their perspective soon shifted. Everypony began to see that Celestia was not only a kind and just ruler, but a loving, caring mother as well.

“How’d you know I was here?” Impact asked. As the question left her lips, the image of a certain purple unicorn popped into her brain. She smiled knowingly.

“Twilight…” the two alicorns said simultaneously, chuckling at their perfect timing.

“So, Impact…what are YOU doing here?” Celestia wondered.

“It’s a science experiment,” she explained. “I’m demonstrating the four states of matter: solids, liquids, gases, and plasmas.”

“Really?” The princess raised an eyebrow as she noticed the shredded table, singed targets, and general disarray. “You appear to be simply destroying things for sheer amusement.”

“Maaaaaaybe…” she replied nervously, “Why do you ask?”

Celestia’s horn began to glow with a pale yellow energy and she levitated over a large green oval-shaped object; an object which brought a smile to the face of every colt and filly in Cheerilee’s class.

“That depends,” she said with a sigh. “I just hope I didn’t haul this thing all the way from Canterlot for nothing…” Her lips curled into a devious smirk. “Care for one last demonstration?”

Over at Sugarcube Corner, Rarity emerged from the bakery, her brand-new white sundress sparkling in the sun. Pinkie Pie and Twilight Sparkle were following right behind her. The elegant unicorn had just made it out the door when Pinkie’s tail suddenly started twitching.

“Hold up, Twilight!” the earth pony said, using her body as a barricade between her best friend and the outside world.

“What is it this time, Pinkie?” Twilight wondered with a hint of sarcasm.

“Oh, nothing! Just an unexpected change in the weather!” she said with a cheer.

“But it’s a cloudless blue sky, darling!” Rarity protested, “And the weather reports don’t call for rain until this evening!”

Out of nowhere, Rarity was drenched with a deluge of an unknown substance which, from Twilight and Pinkie’s perspective, was wet, chunky, and pink.

“AAH!” she screamed, “MY NEW DRESS! IT’S RUINED!!!”

“What the hay was that?” Twilight wondered, silently grateful that she was still standing inside the building.

Pinkie stepped outside and sniffed the strange substance staining the unicorn’s dress. She took a careful lick and her eyes shot open at the sweet taste.

“MMM!” she groaned with delight, “Tastes like watermelon!”

“Well, that was certainly unexpected,” Twilight said with a giggle.

Pinkie Pie was about to go in for a second taste of Rarity’s now-delicious dress when various parts of her body began twitching, which escalated into violent trembling, then paroxysmal convulsing, and finally culminated in what appeared to be a full-blown epileptic seizure. Twilight and Rarity could only stare in horror as their best friend’s body twisted and contorted into the most unnatural of angles, even for a pony as flexible as Pinkie Pie.

“Uh-oh…” she shouted, her voice trembling as she vibrated, “This is gonna be a doozy!”

“What’s going to happen, darling?” Rarity wondered before going back to moaning and complaining about her fruit-splattered ensemble.

“I don’t know,” she explained after she stopped twitching and stood back up on her hooves.

“So somepony gets startled or something,” Twilight said skeptically, dismissing the thought with a wave of her hoof, “You can just warn them before it happens. You know.”

“That’s just it,” Pinkie said, her voice quaking with extreme worry, “I don’t know.”

“What do you mean?”

“The who, the what, the where…IT’S JUST NOT THERE.” she stammered as she paced back and forth, visibly trembling with anxiety.

The two unicorns’ apprehension grew as their pink friend kept rambling.

“Now something very, very bad is gonna happen and I can’t stop it! What if somepony gets hurt…or worse? I couldn't bear the thought of somepony getting hurt because of me! My Pinkie Sense has never betrayed me like this before! Read my lips, Twilight! I. DON’T. KNOW.”

“Well, what do you know!?!?” Twilight and Rarity asked, now thoroughly unsettled.

“All I know is somepony in Ponyville is in for a really big shock tonight…” Pinkie admitted with a sigh.