Several days have passed since the Crystalling. The Crystal Empire was no longer in danger of being buried in the harsh snows of the winter tundra. Everypony living there was grateful and happy. But none more so than the royal couple, Princess Cadence and Shining Armor. Flurry Heart, their newborn daughter, was sleeping peacefully in her crib. Little did the infant princess and her parents know that a horrible event was about to take place.
Ponyville
Fluttershy woke up and fed Angel Bunny. As she tended to feeding her chickens, Twilight Sparkle along with her friend and assistant Spike arrived for a friendly visit.
"Good morning, Fluttershy. How are you?" Twilight said cheerfully. The yellow pegasus turned and waved at her friends.
"Hi, Twilight. Hi, Spike. I'm fine," she replied. "And how are you two?"
"Doin' good, thank you," said Spike. "Taking care of your animal friends as always?"
"Mm-hmm. It's great to be home, and it feels so good to have everything back to normal."
Twilight nodded in agreement. After their fateful battle with Chaos and the Four Fiends, she and her pony friends returned to their normal states. They were able to handle several situations and had their own adventures, until Starlight Glimmer enacted her revenge scheme against Twilight but was foiled when she saw the consequences of her actions and vowed to redeem herself.
"So how is everypony doing?" asked Fluttershy.
Twilight explained. "Well, Rarity and Pinkie Pie are in Manehattan for several reasons. One, Rarity wants to extend the Carousel Boutique; two, Pinkie's looking for the perfect gift for her sister Maud. Applejack's helping her family with Sweet Apple Acres, and Rainbow Dash is still waiting to be a full-time member of the Wonderbolts."
"It seems like they're all doing well."
"Sure does."
Suddenly, the ponies and dragon began to hear something from a distance. "Princess Twilight! Princess Twilight!" the voice called out. They looked around and saw an armored pegasus fly just above them.
"Down here!" Twilight shouted. The pony looked down and saw who he was looking for; he floated down and landed on the ground, almost dropping to his belly, panting from exhaustion. "What happened? Are you all right?"
"I... I came from... the Crystal Empire," he panted. "We... we're under siege from... monsters...!"
Everyone gasped. Twilight especially since she now knew that her extended family was in danger. They carried the guard to the hospital and bought tickets for the Friendship Express. Their destination: the Crystal Empire.
The Crystal Empire
As the three friends approached their destination, they couldn't believe what they were seeing. An entire army of demons not unlike those they had fought on their previous otherworldly adventure had entered Equestria and attacked the Crystal Empire! Several Crystal Ponies panicked and ran as far as they could from the monsters. Some of them even fought back but were taken away as some of the demons opened up portals taking them to Celestia knows where.
"Twilight..." Spike said nervously. "What's happening?"
"I don't know, but we can't let this go on!" Twilight declared. She and the others stood between the invaders and several helpless Crystal Ponies, preparing themselves to do battle.
Fluttershy, regaining some of the courage from her journey rammed her head into one of the monsters while Twilight fired a magic beam into some of them. The demons, finding their enemies too difficult to defeat, opened another portal and escaped.
*music fades out*
Needless to say, our heroes were confused.
"What in the name of Celestia is going on here?" said Twilight.
"AAAAAAAAAAAAAAAHHH!!!"
"Princess Cadence!!" The three ran off to the royal chambers where they found Cadence with here hooves in her face, crying and Shining Armor comforting her.
"What happened here?!"
"Twily..." Shining Armor said solemnly, looking towards an empty crib. Twilight's heart stopped.
"Where's Flurry Heart?!"
"That's the thing: she's been foalnapped!"
"What?! NO!"
"We just..." Cadence sobbed. "We heard of the invasion... *sniff* ordered a counterattack... went into this room... and... *sniff* found it ransacked!! Our baby's gone!!" she cried.
Fluttershy and Spike gasped. "Why...?" the yellow pegasus asked. "Why would anypony do such a horrible thing...?"
As she asked this, a guard came and announced, "Princess Cadence! It's the Crystal Heart again!"
Twilight wondered. Maybe Cid knows about this...
As they reached the Crystal Heart, only three cutie marks were being displayed: Twilight's, Fluttershy's, and that looked like the Crystal Heart itself, the very same design on Princess Cadence's flank.
"Cid!" Twilight said. "What happened?"
"I know exactly who's responsible for this. Please come..."
"Let me go with you!" said Spike.
The Lufenian spirit hesitated. "Spike, was it?"
"Yeah...?"
"You are aware of the dangers that Twilight and her friends informed you of on their last journey, are you not?"
"Yes, but I wanna go this time. I want to go with my friends!"
Cid contemplated the dragon's words. "Very well, Spike. Please enter."
Like before, the Crystal Heart emitted a beam of light, but this time invited the chosen ones in. The two princesses looked in Shining Armor's direction and after a few minutes nodded. "We'll take care of things here."
The two embraced him briefly and went inside with Spike and Fluttershy.
The Chamber of Crystals
Twilight, Fluttershy, Cadence, and Spike all woke up to find themselves in the room the former two knew well.
"Is... is this the Chamber of Crystals?" asked the Princess of Love.
"Looks like it."
"Hey, Twilight. Look at this!" Spike pointed towards Roman numeral I above one of the Crystals. It glowed a bright yellow color, indicating that it had been visited before.
"Ponies, Spike..." said Cid.
"Don't tell me that my daughter's foalnappers came from one of these worlds."
"I am afraid so, Princess Cadence." The crystal under the Roman numeral II began to display images of a war-torn city.
"Decades of long peace had come to an end. The Palamecian Empire have summoned demons from the underworld in their bid for conquest. Four youths from the recently occupied Fynn have begun to flee with Imperial soldiers on their trail..."
The mares held their hooves in front of their muzzles.
"How? Why?" Twilight asked. "Why would anyone do such a thing? And why did they take my niece?"
"I do not know why little Flurry Heart was captured, but I fear nothing good can come from the Emperor's intentions for her." The crystal then displayed a new image: that of an attractive blonde-haired man with a quadruple-spiked crown on his head. "From what I have gathered, his name is Mateus. Do not be deceived by his face. For he is a cunning and ruthless individual with little regard for anyone else, and he views all that oppose him as mere insects that exist only to be crushed by the might of his military. His goal: world domination."
*music fades out*
Fluttershy quivered with fright. She clung to Princess Cadence for reassurance and was pulled into a protective hug. Just then, the crystal opened the gateway to the war-torn world.
"Twilight..." said Spike.
"Yes?" she asked nervously.
"If what Cid says is true... we've gotta go in and save Flurry!"
"My thoughts exactly. Cadence?"
"You don't need to ask. My baby is in the hooves... or, eh, hands of a madman, and I am going to save her!"
"Fluttershy?"
The yellow pegasus was still clinging to Cadence's leg, shaking.
"I... I'll go," she said. "When I first saw her, it was the just the most adorable things in all Equestria. And if anyone hurts a friend and/or any member of my friend's family... They need to be taught some manners."
Twilight, Spike, and Cadence all agreed and jumped in ready to save Flurry Heart.