Author's Note
By the way, if you were wondering, this is in the SS universe but you don't need to read that to understand this fic. If you like the premise (even if it was already used) then like my story and tell me your opinions in the comments. If you don't like it, leave a comment why.
Prologue
Derpy Hooves walked along the streets of Ponyville, and right by her side was her adorable little foal, Dinky Hooves respectively.
She drew an eye to her daughter, who was bouncing happily to move forward towards their destination, which was the Ponyville school.
Derpy smiled warmly at the acts of her daughter, she was something special.
As they approached the school, Dinky turned around and started bouncing backward to look at her mom.
"What is it muffin?" Derpy asked.
"Nothing." The filly sang. "I'm just happy that you're walking me to school today!" She grinned.
"Today's my day off!" Derpy said. "And I took the chance to see my little filly go to school."
Dinky stopped bouncing when they reached the school and jumped at her mother, hugging her.
Derpy returned the hug happily. "Have a good day at school pumpkin."
"I will. Bye, mom!" Dinky left her mother and bounced off to the school grounds.
Derpy thought to herself. "Now... what to do on my day off." She put a hoof on her chin. "Hmm..." She gasped. "I know! Muffins!" With that thought in mind, she started to fly to her favorite sweet shop, Sugercube Corner, smiling while doing so.
For years...
I've worked on this for years...
And I'm so close.
Not even the nobles know, that's for the better.
They wouldn't want this, it's too "dangerous", too "risky."
We'll soon see if that's the truth.
Time...
All of time will be in my grasp, I can almost feel it.
I can witness everything, control fate for the better.
If I were an idiot!
Why do I do this? I know it is risky like Princess Twilight Sparkle herself would tell me, I know it is dangerous like Princess Celestia would warn.
So why do I continue?
To be honest, I don't really know.
Fame, control, curiosity? I can never tell.
I'm so close, just a couple more items then it will be complete.
All I need is... time.
Muffins: Check
...That was all there was to it.
Derpy had her basket of freshly baked muffins in her mouth. She made her way towards the park, where she could eat in peace. The muffins were right below her snout, so she could smell the steamy goodness radiating off of them. She resisted the urge to take a bite, hard enough as it is to resist eating all. She had to save some for Dinky later.
She flew above the green grass. Below were ponies casually walking around, doing their own things.
She flew for a minute before she arrived at the park, then it took another minute to find a good spot for her to eat, presumably a bench where was comfortable.
She noticed an empty bench and went straight ahead to sit on it and started to dig in, taking a blueberry muffin out first, then biting half of it.
If the order was correct, and Pinkie always gets it right, she should have precisely five blueberry muffins, five chocolate chip, five cranberry and five plain. That was the "regular" as Pinkie and Derpy recognized for her order. And it helped that she both got a 25% discount from Pinkie herself and a promotion of her job as mailmare. She could buy this order once a day for a year and still have enough money for more important stuff.
Sadly, she would still be forced to stop eventually since she was to pay for Dinky's school choice in the future, but that's for Future Derpy to worry about.
As she dug in for a chocolate chip, she took notice of the scenery around her. The wind was fluent, and flowed through her mane and coat with little resistance, helping her relax, but also making the muffins get colder a lot faster. There were not a lot of foals around because school was a thing, but there were many mares and stallions out. Not surprising, since it's about lunch time... wait, how long was Derpy here for? School seemed like it just started and it starts at eight o' clock. Odd.
She checked the sun but that was useless since it was too bright and she could never tell the time that way. She looked around for any signal.
Nothing.
"Oh well." She shrugged. "I just have to be ready to pick up Dinky from school." No doubt Dinky would be waiting happily.
"I've done it." Doctor Hooves-
"Time Turner!"
Ahem... Time Turner looked at his creation. It was a blue metal medallion.
"I can't believe I ran out of purple paint. This blue is alright, though."
It had roman numerals around the circumference, and in the middle was a purple spark that cracked and flashed. The spark was contained in see-through glass that was placed in the middle of the object.
"One more incy-wincy thing." Turner grabbed a small brown string and tied it to the medallion. Now it truly looked like a medallion. He took the medallion and put it around his neck. "It, no... The Time Amulet is complete!" He declared.
Suddenly, the huge monitors in his research lab started to flash red and alarms went off.
"Huh?" Turner rushed up to the monitor and inspected them. "What are these signals? I never designed them into the system." He started to panic when, all of a sudden, the Time Amulet started being pulled from Time Turner's neck. The stallion realized and started to pull back on the string. "What... is going... on?!" He strained.
The string soon started to rip to Turner's shock and it was too late for Turner to grab the Amulet as the string ripped entirely.
The Amulet attached to the machine below the monitors with a clang, and it started to shine brightly.
Turner covered his eyes and yelled as some kind of force pushed him back.
Once the light faded away, Turner opened his eyes not to see red flashing monitors, but various blue coding on them. The alarm stopped too, and the Amulet...
"My word..." Turner was speechless.
It was floating in mid air. The purple spark in the middle was replaced by a blue aura, and the Amulet glowed blue and purple brightly.
Turner ignored the Amulet for a second and focused on the monitors.
"Hold on a second..." He typed a few keys in. "This code..." He typed more. "It's... familiar!"
Derpy hummed happily as she entered her home. She stored her leftover muffins for Dinky in a cabinet and went to the living room. When she was about to sit down on her couch to relax, the doorbell rang.
"Coming!" She walked over to the door and opened it to reveal her best friend. "Doc! How nice to see you!"
"I'm sorry Ditzy, but this is not the time to be happy." He had a serious face.
If Doctor called her "Ditzy", then this was serious. "What's going on?" She asked nervously.
"Come." Turner turned and started trotting away.
Derpy made sure to lock the door and quickly followed. She soon caught up by flying and started to walk right next to Time Turner.
"Tell me Doc, what's going o-"
Turner put a hoof to Derpy's mouth. "Not here, this is top secret. We are making our way to my lab."
After minutes of speed-trotting, the two finally made it to Time Turner's home. They entered and went straight to the basement, where his lab was placed.
Derpy quickly noticed the change from the last time she was here. "What happened in here?"
Turner sighed. "There's good news, bad news, terrible news and the unspeakable." He quickly said. "What do you want to hear first?"
"Uhh... good news?"
"The good news is that my Time Machine's done," He explained.
"Oh, that's great Doc!"
"But the bad news is, is that I got strange readings from the Time Amulet that tells me that time is changing." Time Turner said as he was looking for tools around the lab.
"Changing?" She didn't know what a "Time Amulet" was either.
"Something is changing time, yes. And the terrible news is that it's for the worse."
Derpy was shocked. "A-and the unspeakable?"
"It's unspeakable but I'll tell you. I used up all the purple paint and had to use this blue for the Amulet."
Derpy noticed the frustration in his voice.
Turner stopped looking for stuff and went to the control panel beneath his four monitors.
"What are we gonna do doc? I mean, if time's changing for the worst wouldn't that mean Equestria's in danger?"
"Precisely. And that's why we are going to save it."
"How?
"With this." He showed Derpy the Time Amulet.
"Woooah, what's this?" Her eyes sparkled.
"This... is the Time Amulet: My time machine."
"It's so... small."
"Quantity is not everything... or is it volume?"
"Size?"
"Yes, size."
He used another string to hang the Amulet on Derpy's neck.
"How do we... ohhh."
"I see you've caught on. We use the time machine to travel back in time, fix the past, then come back without making any differences in the timeline. And by 'we', I mean you."
"Ohhh... wait, what?!"
Turner held item he was working on, on the workbench. "Here." The item was a white cube with a golden circle on each side, he gave it to Derpy and went back to the control panel.
"Why do I need this?" She asked.
"Timespace is very dangerous to travel in, you could be torn apart as if you've entered a black hole. Well... that's what scientists believe." He said as if it was nothing.
"What?!" Derpy yelled.
"Don't worry you'll be fine. That cube, The Protection, will protect you and it will help you fight in case you need to."
"O-oh..." It helped a little, but it still made her uneasy.
"It's almost set up. According to the readings, the timeshift was in 12,014 A.D."
"After Discord... his first appearance." Derpy realized. "Wait, isn't that whe-"
"Yes, I believe whatever or whoever is changing time is focusing on main history changes. Okay, stand still." He started typing on the keyboard below the monitors. "Here are the Rules of Time Travel which you MUST follow. Don't directly interact with anypony, no talking, nothing. The only thing you interact with is the change in time, this especially goes for your past self. Nothing must be changed except for the incorrect change. You must also never reveal who you are to anypony, not even Celestia herself, got it?"
"I'm not sure about this Doctor. Why do I have to go back in time? Why can't you go?"
"I'm afraid there's no way to come back from time without the use of this machine. And we obviously can't take it with us so it'll have to stay here and pull whoever has the Time Amulet back to the present. I'm the only one who can operate it so I can't go."
"Oh..."
"I'm sorry Derpy, I really am. But you are the only one I can trust right now."
"B-but... what if I mess up? What if I cause something even more bad to happen."
"I believe in you Derpy." She still looked nervous. "Who is the mailmare that delivers letters from Ponyville to Canterlot all the way to the Crystal Empire?"
"I... I am."
"Who travels in the hot sunny days, snowy weather, or a thunderstorm?"
"I do..."
"And who is my favorite mare in Ponyville."
"Me?"
Turner nodded.
"I... I can do this. If there is no one out there that can, then I will step up."
"Yes!"
"I'm doing this for everyone I care about, especially Dinky."
"Thata girl! Now, are you ready?"
Derpy nodded determinedly.
"Alright then, stand still." He instructed.
"Okay."
Turner pushed some buttons on the panel then walked up beside it. He held a lever that was attached to the side.
"Alright, here we go. Remember the Rules of Time Travel."
Derpy nodded and stood still.
"Three, two, one," He pulled the lever.
A bright light escaped the Time Amulet and expanded around Derpy. Her mane rippled like it was being pushed by wind.
All the while Derpy tried to keep her cool.
Then suddenly, Derpy vanished.
In a flash of light, Derpy appeared in the middle of a crowd.
She immediately looked at her surroundings.
"Nopony noticed me?" She asked herself.
She was in a building covered in streamers all the light's were off. She looked outside to see that it was dark.
"Did Doc send me exactly when-"
"Fillies and gentlecolts," Derpy took notice of Mayor Mare on the front stage.
"It is." She realized as her anxiousness grew.
"As mayor of Ponyville, it is my great pleasure to announce the beginning of the Summer Sun Celebration!"
Everypony around Derpy cheered.
"In just a few moments, our town will witness the magic of the sunrise, and celebrate this, the longest day of the year! And now, it is my great honor to introduce to you the ruler of our land, the very pony who gives us the sun and the moon each and every day, the good, the wise, the bringer of harmony to all of Equestria..."
Some birds started to sing.
"Princess Celestia!" She declared as the curtains Rarity pulled from above were opened.
It revealed... nothing.
Ponies grew worried and started to to panick.
"Remain calm, everypony, there must be a reasonable explanation!" Mayor tried to control.
"She's gone!" Rarity yelled from above after searching for any hiding spots.
Everypony gasped, save for Derpy, who knew what was about to come next.
Everypony gasped again as dark mist started to spread from above, then a black alicorn appeared flapping her wings a bit.
The black alicorn spoke. "Oh, my beloved subjects. It's been so long since I've seen your precious, little sun-loving faces."
Derpy nearly fainted.