It was a sunny day in Ponyville. The birds were singing high up in their nests, the sun was shining, and the weather patrol had placed the perfect amount of clouds in the sky. Twilight Sparkle was sitting on her tree home's balcony, reading a book on history. Her dragon assistant, Spike, was wearing a frilly apron and sweeping.
"Wow, a thousand years ago was a really busy year. First Nightmare Moon, and now King Sombra," Twilight thought aloud.
Spike rubbed his chin, deep in thought. "Huh, that is weird. Oh well, it's not like another ancient evil from a thousand years ago will appear in about a year's time, right?" Twilight laughed.
"Yeah, that would be silly."
A scream was heard coming from the other side of Ponyville. "The horror, the horror!", shouted the voice. Twilight closed her book and draped her hooves over the balcony railing.
"Oh no, Spike! It sounds like somepony's in trouble! We need to go help them!", she cried.
"Hey, with the amount of trouble Ponyville gets in, don't you think we should have some sort of organized police force instead of relying on six young mares and a baby dragon?", asked Spike.
"No, Spike, that would be silly."
"Oh, okay."
The duo ran out of the library at top speed, ignoring the ponies running the other way. The citizens of Ponyville were screaming something about slime. One of them ran up to Twilight and stopped her. "Twilight, you need to run! The slime is coming!", the mare said. She quickly turned her head around to check if the slime had caught up, and continued running.
"Huh, that was weird," commented Spike. "What do you think she-" Spike's eyes went wide before he could finish that sentence. Twilight turned her head and looked in the direction her assistant was staring. A colourful slime was oozing throughout the town behind her, seeping under the cracks of doors and through alleyways.
"That's not slime, Spike," muttered Twilight. "It's The Gak."
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The Elements of Harmony and Spike were sitting in Twilight's basement. "Okay girls," Twilight addressed them, "The slime outside is called The Gak. It used to travel across Equestria, invading cities and taking over the minds of any pony it touches. One thousand years ago-"
"Seriously?", Spike interrupted. "One thousand years? What didn't happen a thousand years ago?"
Twilight glared at him. "Quiet, Spike. Anyway, a thousand years ago the princesses used their magic to banish it to the bottom of the ocean and imprison it in the place it was banished to. Now, I just got this letter from the princesses telling me that for some inexplicable reason, they can't do it again and it's up to us. Does everypony understand?"
The five ponies nodded. They had long since come to terms with the fact that the princesses were useless when they needed them the most.
"Do you all have your elements?", Twilight asked. The others nodded. "Let's go save Ponyville! Again!"
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Twilight watched helplessly as she watched her friends get swallowed up by the Gak. They were floating inside the stuff, staring at her. "Gak...", they called to her. "Join us, Twilight. The Gak is amazing. Gak Gak Gak Gak Gak..."
"That could have gone better," commented Spike. Twilight nodded.
"Squishable... Squeezeable..." Pinkie Pie muttered in her goopy prison.
"Stretchable... Bounceable...", added Rarity.
"Are you feelin' it?" added Rainbow Dash.
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Twilight and Spike were standing on a cliff with three other ponies. Below them, slowly climbing up the cliff, was the Gak, in all its rainbow glory.
"Okay, ponies. I've assembled you here because you are the last, best hope for Equestria," Twilight addressed the others.
Doctor Whooves raised his hoof. "Um, I'm just a clock maker. How am I qualified to be the best hope for Equestria, exactly?", he asked. The other two ponies nodded.
"Oops, did I say last, best hope? I meant last hope. We're the only ponies left in Equestria not inside The Gak."
"Oh, well that's discouraging."
"Well, Trixie obviously is the best hope for Equestria! With her magical powers that are much better than Twilight Sparkles, Trixie will smite this 'gak'!", claimed Trixie, standing on her hind legs. Fireworks shot out from behind her, exploding in a plethora of colours behind her.
"Actually Trixie, I really don't like you. Get out of here," said Twilight, picking the azure mare up with her magic and throwing her over the cliff. Trixie landed in The Gak.
"Curse you, Sparkle! I will... gak... have my... gak... revenge gak gak gak!"
Twilight gave a sigh of relief. That pony was annoying. She looked from Doctor Whooves to the other pony. "I'm sorry," she said. "Who are you?"
"I'm the castle janitor. I cleaned the hallways."
"Oh."
"Do we actually have a plan?", Doctor Whooves spoke up. Twilight shook her head. At that moment, the cliff started to shake. The three ponies (and Spike) ran towards the edge and looked down. The Gak had absorbed the bottom of the cliff, and it was starting to fall into the Gak. The ponies screamed.
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It had been a few months since The Gak had appeared in Equestria. Twilight Sparkle was walking with her friends to their favourite restaurant for lunch. They strolled past the tree-shaped Gak and the houses made of Gak. A squishing sound could be heard as they walked, hooves landing on the roads made of Gak.
They reached the restaurant. A sign above the door identified the restaurant as 'The Gak'. The waiter ushered them in and found them a table. After looking over the menu, they placed their orders.
"I would like some Gak, please.", said Twilight.
"I've grown bored of the Gak. I'll have the Gak today."
"I'll have what Fluttergack is having!"
After all the ponies had placed their orders, the waiter left to fetch their Gak. They ate it, paid their bill with Gak, and left to their respective Gak houses.
Everything was Gak.
Everything.
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If you don't feel like reading the story, this sums it up quite nicely.