Once the girls entered the castle, the fairies flew off to the villagers hiding in the treehouse, squeaking in Gingerbread's ear.
"They're right!" he said, turning to the villagers. "We have to fight the Mouse King!"
"Yeah!" Peppermint agreed.
However, Pimm was listening as they made plans to rebel against the Mouse King.
Clara, Applejack, and Rainbow Dash finally snuck to the balcony of the castle, and gasped in horror when they saw the Mouse King having his army toss firewood into a large pile.
"More wood!" the king ordered. "I want this to be an unforgettable show!"
Then he looked up, and just missed the trio duck behind a pillar as Pimm flew up to him.
"All is coming together!" the Mouse King told Pimm. "Soon the Nutcracker will be a pile of cinders!"
"Um... about that..." Pimm stammered, and the Mouse King turned on him.
"What?" he asked.
"Your subjects want to rebel," Pimm said.
"Sweet!" Rainbow Dash whisper-shouted.
The Mouse King snatched Pimm.
"I want every villager, fairy, and general troublemaker rounded up to witness the display of my absolute power!" he ordered.
"I'll do it, sire," Pimm agreed, and flew away.
"Bring out the hostage!" the Mouse King ordered, and two mice soldiers carried out Sunset, who was bound with rope and gagged with cloth.
"Let's see if your friends will be willing to give up their magic to protect you," he sneered to her.
"Is he gonna kill her?" Rainbow Dash gasped.
"We have to get the others before we try and rescue her," Clara said, and the three started looking for their friends, running into two mice soldiers.
"Oh!" Clara gasped. "Uh..."
"What are you three doing here?" one of the soldiers asked, raising an eyebrow.
"The Mouse King sent us," Rainbow Dash said, thinking on the tips of her toes.
"Yeah!" Clara added. "He needs you right away in the courtyard, and if you don't hurry, he'll turn you into houseflies! Or was it horseflies?"
The two soldiers squealed and ran past them. Clara sighed with relief and opened the door they were guarding, only to find it empty.
"Clara!" the Nutcracker's voice cried out, and all three of them stopped short.
"You guys heard that, right?" Applejack rubbed her ears to make sure she was hearing things correctly.
"Guys, were trapped!" Pinkie's voice called out.
"They can't see us!" Fluttershy's voice said.
"Well, obviously!" Pinkie's voice giggled. "The Mouse King put us behind an invisible wall!"
"I thought today was supposed to be a chill day," Rarity's voice whined. "Besides, how can we see them?"
"They clearly can't hear us, either," Captain Candy's voice pointed out.
"Clara," the Nutcracker's voice said again.
Rainbow Dash walked further into the room, slamming her face into the air.
"What the what?" she asked as she fell to the cobblestone floor.
Applejack seemed to realize what happened.
"Stand back," she said, readying her arms as she delivered two swift punches, shattering the invisible glass, revealing her friends, Captain Candy, Major Mint, and the Nutcracker.
"We have to hurry," Clara informed them. "The Mouse King is building a bonfire!"
"And he has Sunset!" Rainbow Dash added.
"And he'll try and kill her for our magic!" Applejack finished.
"Then we have to hurry!" the Nutcracker pulled out his sword. "I doubt this bonfire is to warm the castle."
The group ran onto the balcony, seeing all the villagers and fairies gathered around the Mouse King. Sunset was still in the tight grips of the soldiers, with a massive bonfire next to her.
"Sugar Plum Princess or no Sugar Plum Princess, that rat has to be stopped!" the Nutcracker said.
"I'll give you magical girls ten seconds to reveal yourselves!" the Mouse King shouted. "Or your friend gets it!"
Sunset screamed through the gag as the soldiers dragged her closer to the fire.
"Not today, rat!" the Nutcracker jumped off the balcony.
"Ah, welcome to the party!" the Mouse King said. "You girls have three seconds... two... one... throw her in the fire!"
"GO DIE IN A FIRE!" Rainbow Dash jumped down as well. Twilight was right behind her, using her telekinesis to force Sunset out of the soldiers' grip, undoing the ropes and gag. Sunset quickly ran over to her friends.
"What did I miss?" she asked.
"We had a setback with the fake Sugar Plum Princess castle," Rainbow Dash said bluntly.
"There's more to being a king than having a crown!" the Nutcracker yelled to the Mouse King, who he was dueling.
"Oh? Suddenly you're an expert?" the Mouse King sneered.
"You'll never gain their loyalty until you've earned their respect!" the Nutcracker shouted.
"Huh," Rainbow Dash said as she kicked a mouse out from under his legs. "That's the method to my madness."
"I don't need their loyalty!" the Mouse King spat. "I don't even need them!"
He shot blasts at the villagers and fairies, and they all turned to stone, even if Rarity tried to protect them with her shields.
"Hmm," the Mouse King said. "How about taking your powers now?"
He aimed his staff at Rarity, and suddenly, white magic flowed out of her and into the staff, dulling her geode as the shields disappeared and she collapsed to the ground. The Mouse King shot a blast, and crystals speared one of the pillars.
"Why, you little--" Rainbow Dash sped forward, but the Mouse King blasted her too, and her magic flowed into his staff.
"Argh!" she said, trying to use her super speed. "I--I can't go fast anymore!"
"How about you slow down even more?" the Mouse King blasted her again, and suddenly, it took her ten seconds to make just one step.
"How... dare... you..." she hissed in slow-motion.
"This ends now!" Pinkie threw a handful of sprinkles that exploded, but she too lost her magic.
"Twilight, you have to hide," Sunset said. "You need to keep your magic!"
"What about you?" Twilight asked.
"I'll be fine," Sunset suppressed a weak grin as her magic was forced out of her.
Twilight nodded and ran away, and the Mouse King took Fluttershy and Applejack's magic.
"Ah," he said, looking at his staff, the ruby now colorful. "Now, let's end this, Nutcracker."
He shot a blast of magic, and quickly sped away as the sprinkles exploded.
"Let's get the real fun going," the Mouse King said, and suddenly, he started growing larger and larger. Fluttershy squealed and ducked behind Applejack in fear as he looked at the six standing below him, the size of ants in his eyes. He roared with laughter as he kept abusing the geodes' powers, eventually using crystals to spear the Nutcracker to the side of the bonfire.
"NUTCRACKER!" Clara screamed, now in the courtyard. She rushed over to the Nutcracker as the Mouse King leaned over them.
"Make your choice, Nutcracker," the Mouse King said. "Dismemberment or barbecue?"
"No!" Clara stood up defiantly. "You're nothing but a coward hiding behind a magic wand!"
"Oh, snap!" Sunset cut in. "You need some cold water for that burn, mouse?"
"Oh, I see your mouth is still far too big," the Mouse King said, aiming his staff at Clara. The Nutcracker thrust his sword between her and the blast of magic, and it reflected off, causing the Mouse King to shrink. He dropped his staff in shock, causing the crystal to shatter, and the girls' magic was restored in them as the Mouse King found himself standing in the middle of his crown, the size of a... well... mouse. He squeaked as he jumped through a hole into a sewer.
"That's where you belong!" Major Mint scoffed.
Twilight peeked out from behind the pillar.
"Where'd he go?" she asked.
"He's gone," Applejack stared at where the Mouse King had disappeared.
They all turned and saw Clara hovering over the Nutcracker, his paint chipping.
"No, no, no," Clara said.
"It's okay," the Nutcracker said. "I'm just wood, remember?"
"You're more than just wood," Clara said. "Prince Eric."
She gave the Nutcracker a kiss, and he was enveloped in blue magic.
"Enter transformation," Rainbow Dash and Sunset said at the same time.
And once the magic disappeared, it revealed a young man where the Nutcracker once stood.
"It's Prince Eric!" Captain Candy pointed at him.
Clara helped up Eric, and a pink light covered her, transforming her nightgown in a pink glittering ballet dress with silky ballet slippers. Her hair curled up, and a golden tiara formed on her head.
"Of course," Eric gasped. "The princess has been with us all along!"
"What?" Clara looked down at her new clothes.
"It's you!" Eric said. "You're the Sugar Plum Princess!"
Rainbow Dash smirked and held out her hand. Sunset rolled her eyes and started digging in her pocket for ten dollars.
"I won two bets in one movie!" Rainbow Dash exclaimed, holding out the two bills. "How is that even possible?"
"You called it out before me," Sunset elbowed her in the side, and they both started laughing as the world around them lightened up, the Mouse King's spells and enchantments undoing themselves. The people turned back to normal, the fairies fluttered around the newly pink castle, and the bonfire disappeared, revealing the fountain underneath it.
"It's time to take your place as king," Clara said.
"Well, if the people want me to," Eric blushed with embarrassment.
"Three cheers for Prince Eric!" Major Mint pumped his fist into the air, and the villagers followed suit.
"Well then, King Eric," Twilight said. "What should we do now?"
"I think we should celebrate," Eric turned to Clara.
~Time skip~
The dancing lasted for hours, and finally, Clara and Eric walked to the center of the courtyard.
"The pas de duex!" Twilight sighed happily.
"Say what now?" Rainbow Dash turned to her as Clara and Eric began dancing. They performed a lovely duet together as Parthenia around them was rid of the Mouse King's spells. They finished dancing, and a little girl handed Clara a bouquet of flowers.
"Thank you," the now King Eric said. "As your new king, I will let the wisdom and leadership of my father be my guide."
Everyone cheered as he turned to Clara.
"Clara, would you do the honors of being my queen?" he asked her.
"Say yes! Say yes!" Rarity begged in the background.
Clara looked down at her locket.
"This locket was supposed to take me home," she said. "But now, I feel as if I'm already home."
She and Eric shared a kiss, and Rarity fainted.
"So... how are we gonna get back home?" Rainbow Dash asked.
"I don't know," Twilight replied. "But we could always stay here."
"You mean stay in Parthenia?" Pinkie squealed. "Count me in!"
Suddenly, Pimm flew by, with the tiny Mouse King on his back. He snatched the locket off of Clara's neck and smashed it open, releasing the magic inside. The snow fairies quickly froze Pimm into an ice statue, and they fell in the distance.
Eric turned to Clara, who was now disappearing. He tried to grab her hand, but his went through hers.
"Clara!" he cried, and turned and saw the Equestria Girls starting to disappear as well in streaks of white. In their eyes, the world around them was turning into light.
"Eric..." Clara breathed before she disappeared entirely.
"Clara!" Eric yelled as the entire world turned into light for the Equestria Girls.