There are awful things out there.... Horrors that I wouldn't wish on the most foul of beings... Prey they never find your world.
Contrary to what everypony believes, princess Luna does sleep during the night, in a way. Every night, she lays in her bed, watching the dreams of each and every intelligent creature throughout all of equestria; a silent, ever watching guardian, in a meditative state. The cool breeze of the night air blowing gently through the curtains, caressing her still body and rustling her midnight fur, is the only indication that her chambers aren't frozen in time, as she lays unmoving, still and silent as the grave.
However, this night was not a regular night. Although appearing calm and still on the exterior, Luna was panicked as she observed the dreamscape, to find it awash with night terrors, dreams full of fear; dreams of demons, monsters and hellspawn that nopony should ever even have to imagine, let alone dream about with such clarity. As the fearful cries of thousands of terrorised consciousnesses echoed about the dreamscape, Luna struggled to comprehend what she was witnessing. Even during the time that Nightmare Moon had control of her body, Luna had never seen this much sheer terror. But what worried her the most, was that all of the nightmares, all of the horror she was viewing was the same, no matter the race, age or gender of the dreamer: demons appearing from portals, and immediately causing havoc, slaughtering ponies, and destroying structures.
These were not simple fears that the ponies needed to overcome manifested in a dream, as nightmares should be. Something was causing this.
Something maleficent.
And whatever it was had enough power to effect the entirety of Equestria.
It was upon this realisation, that Luna jolted out of her slumber, knowing she must alert her sister. Kicking her bedsheets off as she sprung to her hooves, she was up and out of her door before the bedsheets hit the ground, the sound of her galloping in the direction of Celestia's room through the once silent corridors alerting the night guard to her urgency, rushing past as they jumped out of her way.
Celestia awoke drenched in sweat, and hyperventilating, with the blankets tangled around her legs, startled awake from what had been an awful nightmare, in which many of her ponies, including those she held dearest to her heart, were torn to pieces in front of her very eyes, and she was helpless to stop it. Dazed, she looked about her room with wild eyes, trying to locate any of the demons that had been tormenting her, only to calm down slightly when she realised she was in her bed, and safe. Her heartrate slowed a little, before skyrocketing again at a deafening series of bangs. Again, she looked frantically around the room, trying to locate the source of the thunderous sound.
Quickly, she realised the horrifying sound of approaching demons was only somepony knocking furiously on her door, shaking it in it's frame, nearly bursting though, but still having the decency to wait to be allowed in, even with the obvious urgency in the knocking. Shaking her head to try to clear some of the fear from her head, Celestia opened the door with her magic, allowing her sister entrance.
"Sister, I have news of dire importance!" Luna exclaimed, approaching the bed with haste, sweating and panting from her unplanned run through the castle.
"Lulu? What is it? Did you have the nightmare too?" Her eyes widened again, as realisation came to her. "It must mean something! It could be a prediction! A premonition! We must gather the elements!"
Celestia gave her sister no time to respond, leaping from her bed and making her way towards the doorway, not caring for her ragged look, and failing to notice Luna's panting until she spoke again.
"Nay, sister, not I. The entirety of equestria has been witness."
Celestia stopped in her path, her entire body tense and unmoving, as if she had suddenly frozen. "You mean to say...?" She trailed off, unable to accept that this could happen to her subjects while she slept.
"Indeed. Every consciousness that was asleep in that moment, dreamed the most horrible of dreams. Each and every one the same as the other; their loved ones slaughtered mercilessly before them. This is not premonition, but control. Something is forcing these dreams upon our ponies, and we must find a way to stop it."
"You're right, Lulu. We have to stop this as soon as possible. I'll tell Twilight to alert the elements. You go to Ponyville and help them, while I will stay here to co-ordinate efforts, and keep the population calm. No doubt there will be mass panic once ponies realise they all shared the same nightmare. Keep me updated through dragonfire."
With that, Celestia gave her sister a brief nuzzle, before turning to depart, hastily going towards the communications area of the castle, and leaving Luna on her own. A stern frown formed on her face as she thought about her night bringing terror to her ponies once more. As anger took hold, she made her way to the balcony, leaping high into the sky, catching the air in her wings and going into a steep dive, before leveling out and shooting towards Ponyville with fire in her eyes.
In the laboratory of her castle, Twilight lifted her head from her work on the portal mirror as a familiar sensation tingled across her flank. Looking back, she could see her cutie mark pulsating, alerting her to a problem. She looked towards the clock, which read as two-twenty seven in the morning, and frowned, before talking aloud to herself. "Really? The cutie mark thing still happens, even at this time of night? Hmm, maybe it's because I was awake anyway."
Deep in thought, she made her way to the throne room, only to be startled by frantic knocking on the front door of the castle. "That must be whoever else got the alert," she mused aloud, heading towards the door. When she opened it, she was greeted by the sight of Rainbow Dash and Rarity.
"Girls! Did you get the cutie mark signal too? Did it wake either of you? Did you..." She trailed off as she noticed the looks on her friends faces. They both looked as if they had seen a ghost. Rarity's eyes were wide with fright, and her lip was trembling. Rainbow was hovering off the ground, clutching herself as she looked around anxiously. "Girls, what's the matter?" The looks on their faces was worrying her; She'd never seen her friends look this scared before
"Oh Twilight! It was Terrible! I had the most awful nightmare, and when I woke up, my cutie mark was blinking, so I ca-"
Rainbow cut Rarity off. "Hey! I had a nightmare too! There were these monsters everywhere! Not that I was scared!" She added, looking away and rubbing her front leg, touching down on the ground.
"Of course you weren't, darling," Rarity put her hoof on Rainbow's shoulder sympathetically. "I don't suppose you had the nightmare too, did you Twilight? " she asked, looking towards her expectantly.
"No, I was awake and working on the portal. But if you both shared this nightmare, I wonder how many other ponies had the same one." While she was talking, Spike came running, hugging Twilights leg as soon as he was close enough.
"Twilight! You're okay! I had a really bad nightmare! It was horrible!" He cried, his voice muffled by twilights fur. Shaking hard, while clutching twilights leg hard enough to cut off blood circulation, and staining her fur with tears, it was obvious he was traumatised by what he had seen. Suddenly, He jumped away from Twilight and belched a cloud of green smoke that formed into a scroll. Twilight quickly grabbed it in her magic, rubbing Spike's back reassuringly when he grabbed her leg again. Opening the scroll, she began to read aloud.
"Dearest Twilight,
A great curse has come upon the entirety of Equestria.
Tonight, everypony who was asleep shared the same nightmare; one of demons causing pain and suffering, murdering ponies in the most evil of ways. This was no natural happening; it is the nefarious scheme of somepony evil, and I intend to find the culprit. I have sent Luna on her way to help you, while I will stay in Canterlot to keep the public calm. Gather the elements and try to work out how this happened.
Your friend and teacher,
Celestia"
Twilight looked up from the letter with hardened eyes