They hurried down the street, looking for any sign of Flitter or trouble, but there was no immediate sign of Flitter. For that matter, there wasn’t much sign of anypony, as pretty much everypony was asleep in their homes by this time of night. It was possible that Flitter’s scream could’ve woken someone up, but all of the houses in the town remained quiet and dark, and Flitter’s scream did not sound again. Without any further commotion, it was unlikely they were going to draw anypony out at this hour, which was good in that they wouldn’t be in any danger, whatever danger there might be, but also meant they weren’t likely to give any help.

But beyond finding Flitter, though, Rainbow and Spike didn’t really know what they were looking for. To them, Ponyville seemed as peaceful and quiet as could be expected given the late hour. But the Doctor seemed to know what to be looking for, and roughly what direction to be heading for, because he led the way through the streets, weaving through them as he stubbornly worked to head west, in the rough direction where Flitter’s cloud house would be. Since Rainbow knew the Doctor couldn’t know the layout of Ponyville, she assumed the Doctor had pinpointed exactly what direction the scream had come from. If so, Rainbow was impressed; he must have good hearing.

After a couple blocks, though, they still hadn’t seen anything amiss.

“We *pant* sure she’s even *pant* out here, or even *pant* in trouble?” Spike wheezed, struggling to keep up with the faster pace of the two ponies, both of which were in better shape than him. “I mean, *pant* Flitter couldn’t have gone *pant* that far, *pant* could she?”

“If she flew, she could,” Rainbow admitted, as she stopped to pick up Spike by the spines and put her on her back to ride. “Speaking of which, Doc, maybe we shouldn’t be looking on the ground. Maybe we should be looking in the sky!” she pointed up with a hoof.

“How far can she fly?” the Doctor asked, pausing at an intersection to choose where to head next.

“All the way, if she wanted,” Rainbow used the moment to glance around. “But nothing really seems amiss out here…and if Flitter did fly, I have a hard time seeing what could be around to put her into danger.”

“Oh, they’re out here all right,” the Doctor assured mysteriously as he picked a direction confidently and proceeded forward at the same breakneck speed. “And it wouldn’t matter where Miss Flonger is, they could get at her if they really wanted. In fact, she’d be a prime target, being active and away from the rest.”

“But who’s ‘they?’” Spike asked.

“And where’s Flitter?” Rainbow asked. “If something has stopped her, then she probably landed, and then Spike would be right, she wouldn’t have gotten far…” she spread her wings suddenly. “Spike, hold on, I’m going to fly up and get a bird’s eye view of things!”

“Miss Dash, wait!” the Doctor began to object, but Rainbow had already taken to the sky, Spike clinging tightly as the blue pegasus rose rapidly into the air. Momentarily impressed to see her flying so effortlessly, the Doctor called up a warning; “Be careful!”

Rainbow went on up until she was quite high above the village. There she parked herself and started scanning the world below her for any sign of Flitter. Spike leaned over to look as well, one set of claws tightly gripping his ride’s rainbow mane to keep from falling. Finally, after a tense moment, they spied their target.

“There she is!” Spike cried, pointing down at the grey-blue pegasus, currently galloping wildly through the empty streets, appearing to be in a panic.

“Doc, this way!” Rainbow called to the stallion below, and quickly flew off to catch up with the other pegasus.

Rainbow and Spike arrived first, Rainbow swooping in above Flitter. “Flitter, what’s going on?!” Rainbow shouted in her direction.

Flitter spun to face them, in a panic. “Be quiet and get down here!” she exclaimed urgently in a harsh whisper. “They’ll notice you!”

Rainbow immediately dropped to the ground with a thump. “Who’ll notice us?” she asked, puzzled. “What’s got you so spooked?”

“I…I don’t know exactly!” Flitter admitted in a panic, trotting in place as she frantically scanned the street around her. “But they’re there! And they were chasing me, these…these things! They’re all shadowy and…and misty, but there was definitely some sort of visible shape and creature behind it all and it did NOT look friendly.”

Rainbow frowned. “You sound like you’re describing a ghost…but ghosts don’t exist…don’t they?”

“Depends on what you mean by ghost,” the Doctor remarked as he arrived at the group, having ran the whole way but hardly seemed winded. He, too, seemed alert and on guard for anything malicious out on the streets.

“But last I checked, ghosts don’t have shadows,” Spike pointed out from Rainbow’s back.

“These did,” Flitter insisted.

“They aren’t your usual kind of ghosts,” the Doctor remarked, turning to Spike. “Mister Spike, you still have my screwdriver?”

Spike looked at his claws and saw that he did, having forgotten he had it when they ran off so quickly. “Yeah, here it is,” he announced, turning it on. “You want me to start waving it around?”

The Doctor grinned, pleased that the dragon was following with his thinking. “If you could please, Mister Spike.”

So Spike did, waving the glowing rod around at the street, focusing on no particular area.

“What the hay is that thing?” Flitter asked, eyeing the sonic screwdriver with distrusting eyes.

The Doctor turned to reply, but he was cut short of that chance when the device started to trill again, this time more urgently than at the library and doing it no matter where you pointed it.

The Doctor didn’t even need to look at it before he spun around, on the defensive. “They’re here,” he announced grimly.

Rainbow followed the Doctor’s example and also took up a defensive position, but she still didn’t understand. “Who’s here?” she pressed.

It was then that she noticed something shadowy out of the corner of her eye, and when she glanced to look at it, she saw it wasn’t alone. Flying in a swarm that stretched across the width of the street were several balls of shadowy mist; dark and unclear shapes that did look something like ghosts, only they really did cast a shadow on the ground, and looked very dangerous like Flitter said. With a chill running down her back, Rainbow noticed they were rapidly surrounding them from all angles. Even the sky was quickly blocked off. Flitter began to whimper and tremble as they all pressed themselves together in a group with nowhere else to go.

“Doctor,” Rainbow repeated, with more urgency, “Who are they?”

The Doctor had his eyes narrowed. “They’re called Dimenost.”

“Dimenost?” Spike repeated as he gazed warily at the surrounding swarm of shadowy beings. “What the hay are Dimenost?”

“Little opportunists, that’s what!” the Doctor snapped, and then turned to address the swarm. “Isn’t that right, eh? Eh? You all saw me crashing into this universe, so you’d thought you’d come and join the party, hmm?”

“Uh, Doc, I don’t think they can talk…” Rainbow began, but she was surprised when the swarm responded.

“The inhabitants will accommodate the Dimenost,” an unearthly and hauntingly powerful voice echoed out from within the apparently intelligent swarm, sounding distorted. “The tear has granted the Dimenost access to this realm. This cannot be reverted.”

“Oh really?” the Doctor challenged as he stepped towards the swarm, fearless. “And how do you plan to manage that? Because anyone worth their salt can see that you are all still quite out of phase at the moment! You can barely interact with this world at all! How do you plan to make them do anything?”

“The Dimenost have other ways of presenting themselves, Outsider,” the voice stated confidently.

This sounded very ominous to the other ponies, but to the alien Doctor, his attention fell on the finer details.

“Outsider? Outsider?” he repeated, incredulous, then suddenly grinned. “Oh! OH! You don’t know who I am! Ha!” he turned to the others brightly. “They don’t know who I am! No idea what I can do! Oh, they saw me arrive all right, but they must not have gotten a good look at me! Oh, this is brilliant!”

“The Outsider will not mock the Dimenost,” the voice commanded, sounding perturbed.

“Or what?” Rainbow challenged, feeling braver with the Doctor being so unintimidated by the shadowy beings. “What are you going to do, huh?”

A bolt of lightning suddenly flashed out from without the swarm, impacting the ground right before Flitter’s hooves. Startled and terrified by the event, Flitter screamed and leapt off the ground and onto Rainbow’s back, joining Spike. Unprepared for the sudden increase in weight, Rainbow’s legs buckled, and all three tumbled to the ground forming a heap of bodies.

“The inhabitants will accommodate the Dimenost,” the voice ordered again, the swarm still crackling with energy to show it could do the stunt again without warning. “The inhabitants will not challenge the Dimenost.”

The Doctor was still not swayed by their show of force. “Pfft!” the khaki-colored stallion said, blowing a raspberry. “So you can hurl a few lightning bolts! That’s all just flash and pizzazz and we both know it! And they can only stun at best here, so all you’re succeeding at is delaying the inevitable! And anyway, I may not have been here very long, but I highly suspect these ponies are not just going to roll over and let you overpower them. Not that it’d come to that, because you’d have to get through me first!”

“The Outsider will not stop the Dimenost. The Dimenost cannot be removed from this realm. The tear has presented the means.”

“Oh, I know about the tear, and you know I know too, because that’s how you knew it was even there. And I also know that if you lot are all still so out of phase and the best you can do is simple stun lightning, that tear isn’t very big, not enough for you to get into this realm as fully as you’d like! So your attempts to invade this world is really just grabbing at straws!”

“This will not remain so. The tear has presented the means.”

“And what do you mean by that?”

“The tear is growing.”

The Doctor abruptly stopped, his eyes widening some. “What did you say?”

“The tear is growing.”

The Doctor went quiet for a moment. Rainbow, extracting herself from the heap she had been pinned under, noticed and didn’t like what it implied.

“Doc,” she asked slowly. “What does that mean?”

The Doctor turned and snatched his sonic screwdriver from where Spike had dropped it in his fall. “It means this conversation is over, Miss Dash,” he replied as he tweaked the device with his hooves. “Fortunately, what the Dimenost haven’t realized yet, is that I “have other ways of presenting myself” too.” And with that, he popped the device into his mouth, spun around, and activated it, the device making its trademark buzzing sound. Only this time it was at a higher pitch, suggesting it was doing something different from before.

Whatever it was doing, the effect was immediate. The disembodied voice of the swarm suddenly let out a cry of annoyance as the swarm all started to swirl around, their forms muddling together as they were blown outward from their prey by some other force. Within moments, they had all dissipated into mist and vanished from view within the darkness of the night. And like that, the silent night they had known before settled upon the street again. The others looked around in surprise.

“Well,” Spike remarked, somewhat shell-shocked by what had just transpired. “That escalated quickly.”

“What just happened?” Flitter demanded, still panicked as the Doctor removed the sonic screwdriver from his mouth and was attempting to put it back inside his jacket with little success. “What did you do?”

“Chased them off by irritating the fabric of space in this area enough that they were forced to retreat back into their bubble of existence,” the Doctor replied quickly as he gave up on trying to put the screwdriver back in his jacket and instead tucked it behind one ear like a pencil.

“So you beat them?” Flitter asked, brightening slightly.

“Oh no, the space-time irritation only lasts about a minute at best and then they’ll be back and angrier than before,” the Doctor replied as they turned to look at them. “So what we need to be doing right now, while we have the chance to do it, is to RUN!” he immediately galloped off back in the direction they had come. “Back to the library!”

Rainbow didn’t hesitate to follow and immediately sped after the stallion with Spike following her lead. Flitter still didn’t trust the Doctor, but she was quick to decide she’d rather be around the Doctor than the much more intimidating Dimenost and brought up the rear. They had barely gotten as far as a block before the Dimenost began to reform, fading back into existence, and were soon giving chase to the fleeing ponies and dragon.

“The Dimenost will not be stopped by the inhabitants,” the voice stated darkly and coldly as the swarm of dark shapes moved to descend on them. “The inhabitants will be punished for challenging the Dimenost.”

The swarm suddenly unleashed several bolts of stun lightning at their prey, dangerously coming close to hitting several of them repeatedly. It caused Flitter to panic even more and give them all incentive to run faster. Rainbow quickly saw that they just weren’t going fast enough on hoof.

“We need to go faster!” she declared, and turned her head to Flitter. “Flitter, grab Spike and start flapping! I’ll be right behind you!”

Flitter didn’t argue, grabbing the little dragon and unceremoniously tossing him onto her back as she took to the air, surging ahead and away from the pursuing Dimenost. Rainbow insured they were safely away before taking to the air herself, staying low as she swooped over the Doctor who was still pressing on by hoof.

“Brace yourself, Doc!” Rainbow called as she dropped down to grab him around the middle.

“Now hold on, Miss Dash,” the Doctor began, having his doubts about this plan. “I’m not so sure this is such a good ideeeeeeaaaaAAAA!”

He trailed off as Rainbow heaved on his body, flapping her wings harder as she lifted his body and both rose into the air. They surged ahead as well, catching up with Flitter. The Dimenost soon fell behind. Apparently they were unable to go as fast, but they still made their anger known.

“The inhabitants will not escape!” the voice called after them as the swarm continued to lash stun lightning in their direction, to little avail. “The Dimenost will prevail!”

Their threats did not make the fleeing group want to slow down though, and they pressed on until they arrived again at Twilight’s library. By then, there was a notable gap of distance between them and the Dimenost, but now they had arrived, the shadowy swarm was starting to catch up, the shadow they cast blotting out the light of the moon as they drew nearer.

“C’mon, everyone inside!” The Doctor said, pushing everyone into the tree building the moment they were on the ground again. Once inside, the Doctor slammed the door shut behind him. He pulled out his sonic screwdriver and started to mess with it again. “I need something to amplify the sonic’s power! Like a battery or something! The more power, the better!”

“I think I know just the thing!” Spike declared and threw open a door tucked into one corner of the library’s lobby and proceeded down the staircase that sat beyond. “Just a second!”

“Hurry!” Flitter squealed, looking through the window as the Dimenost arrived outside the building and started to surround it.

Spike was back quickly, bringing with him a plain box. “One of Twilight’s old science experiments!” he explained briefly as he brought it to the Doctor. “It should still have a magical core with a good charge on it that you can use for power!”

“Magic?!” the Doctor repeated, taken aback. “Magic?! You mean to tell me—” he stopped and shook his head roughly. “Never mind! If it means power I can use, I’ll take it!” Pulling open the box, he started to attach the box’s inner workings to his sonic screwdriver.

“Doc!” Rainbow suddenly called as she and Flitter backed away from the window. “They’re getting in!”

Sure enough, the shady bodies of individual Dimenost had started to swoop down on the library and then started to fly straight through the walls of the library like the ghosts they resembled.

“Got it!” The Doctor suddenly cried, and flipped a switch on his screwdriver. “Tally ho!”

The screwdriver started to buzz again, its light pulsing, and once again the effect was immediate as the Dimenost, just about to reach their targets, were suddenly swept aside and flung back out of the library, flying through the walls again all willy-nilly. Outside, the swarm billowed outwards as it circled the library, like it was being pushed back, until a sizeable dome of empty space now separated the building from the intruding enemies. The Dimenost attempted to push back in, but seemed unable to. They were consistently pushed back to the borders of the invisible dome that kept them at bay every time. In silence, the group watched this proceed under the buzz of the amplified sonic screwdriver, the tension still hanging heavily in the room.

Unsurprisingly, it was the Doctor who finally broke it. “Ooh, ‘tally ho,’” he repeated, putting a hoof to his lips, a grin starting to form upon them. “I rather like that. Maybe I’ll make that my new catchphrase…‘tally ho,’ it’s got a nice ring to it, doesn’t it?”

The others stared at him for a moment.

“You are absolutely crazy!” Flitter suddenly exclaimed at him.

The Doctor made a sweeping and comic bow at this, as if he was aware of this fact and quite proud of it. It made Rainbow laugh, and everybody started to relax some.

“But I don’t understand,” Spike spoke up finally, examining the contraption the Doctor had set up, his face illuminated by the strobing glow of the screwdriver. “What exactly did you do?”

“The same thing I did before in the street, only ten times better,” the Doctor explained. “By hooking up the sonic to an added power source, I can use it to disrupt this area of space perpetually, for as long as the power source holds out. It doesn’t get rid of the Dimenost, but it’ll keep them from being able to reach us, blocking them kind of like a shield or bubble.”

“What about the ponies that are outside the library?” Spike asked, worrying for their safety.

“Unless the ruckus we’ve made has woken any of them up, they should all still all be asleep and thus safe for now,” the Doctor promised. “The Dimenost are not like us biological creatures. They don’t sleep at all, and thus don’t understand the concept of it at all. So they don’t treat a sleeping person…or pony…as a threat or anything worth their attention otherwise. They might as well be actually dead in the minds of the Dimenost, so the joke’s on them in a way. Besides, they’re probably more interested in us, me especially, because we’re the ones that stood up to them, and they don’t like that. They’re going to want to stop us…or at least try and figure out all they can about us in a quite unpleasant way.”

“But as long as that thing works, the Dimenost can’t get at us in here,” Rainbow recapped, pointing a hoof at the buzzing sonic screwdriver.

“Correct!” The Doctor confirmed brightly then shrugged. “Unless they find a way around it, which…isn’t entirely impossible…they are clever things, the Dimenost. This group seems especially so, in fact, if they’ve figured out a way to make the tear bigger…”

“And just who are these Dimenost?” Flitter demanded, pressing her snout into the Doctor’s. “And don’t play ignorant either! You clearly know them far better than you’ve told us!”

“Well, the Dimenost are actually more common than you’d think,” the Doctor explained. “It’s just usually they can’t ever reach us, because they normally exist outside any given universe.”

“Wait…” Spike said, rubbing his forehead as he tried to puzzle this out. “…outside the universe?”

“Okay, picture the universe like a big bubble,” the Doctor explained, holding up his forehooves to outline such a bubble. “It’s not really bubble shaped, but this is to help you picture it in your heads better.”

“Okay, so I’m picturing the universe as a bubble,” Rainbow Dash said, picturing a soap bubble with Equestria, the sun, the moon, and stars sitting inside of it in her head.

“Now picture another bubble that sits around it, like the universe is a smaller bubble inside of a bigger bubble,” the Doctor continued. “That bigger bubble is where the Dimenost exist and live. It’s called “the Fringe,” a kind of final boundary that separates one universe from everything else around it. Every universe has one, but the universe itself can’t interact with it, nor can the Fringe and everything within it interact with the universe, because they are both self-contained from each other in separate bubbles, with no way for one to enter the other, so to speak.”

“So…how are the Dimenost getting into our universe if they aren’t supposed to be able to?” Spike asked.

The Doctor winced and rubbed the back of his head, ruffling his bronze-colored mane. “Yeah, that’s actually kind of my fault,” he admitted. “See, in order to go from my universe and into yours, I kind of, sort of, had to punch a hole into it, and in so doing, punching a hole in the Fringe as well.”

“You WHAT?” Flitter repeated, turning angry. “So this is YOUR fault?”

“Do keep in mind that I crashed into this universe, so it wasn’t intentional,” the Doctor explained. “I didn’t really have any control over it at the time. Heck, I don’t even think I was conscious for it, but remember those bubbles I told you to picture? Basically what happened is that me and my TARDIS pushed on the bubbles until they touched, joining together, so to let me in. That, in turn, also created a way for the Dimenost to get in as well. That’s the “tear” the Dimenost were talking about. It’s out there right now, probably right over Ponyville if you could see it…which you can’t, because it’d sit on a different dimensional plane from us, but still…”

“But you were telling them that tear was too small for them to get in,” Rainbow stated, remembering the Doctor’s confrontation with the shadowy beings.

“And it should!” the Doctor promised. “Even the TARDIS punching through it wouldn’t have left all that big of a hole, and whatever hole it left would’ve eventually closed up naturally, on its own, in fairly short order. It wouldn’t have been worth the Dimenost’s time to even try to make use of it, usually.”

“But they said it’s getting bigger,” Spike said.

“They must be causing that, not me,” the Doctor said. “Somehow the Dimenost have figured out some way to force that little tear to form into a much bigger one, so they can get into this universe more fully.”

“So more of them are going to be coming?” Flitter exclaimed, turning fearful again.

“More than that, they’ll become more tangible, more physical, faster, better, stronger, and so forth,” the Doctor said. “See, at the moment, they’re only kind of here. They’re here in presence, mentally and visually, but physically they’re all still in the Fringe, because the tear still isn’t big enough for them to get all the way through. You’re really only seeing a part of them right now. That’s why they seem so much like shadowy ghosts. And as far as you and I are concerned, that’s really all they are. They’re “out of phase,” as the proper term would have it. They can flash their lightning at us, but like I said, that can only stun here. Other than that, they can’t touch us, hurt us, or do much of anything to us except make verbal threats for now. That and crowd us…which I don’t honestly know what might happen if they did that, but I’d rather not find out.”

“But as the tear gets bigger…” Rainbow prompted, starting to understand.

“…the more that’s going to change,” the Doctor finished, nodding. “And suddenly they’re going to become very, very real, not to mention dangerous to us all if we let them.”

“But what they do they even want then?” Flitter asked. “Why are they here?”

“Oh, well, envy mostly,” the Doctor replied, nonchalant. “The Fringe is really just this big misty expanse that they fly around in and not much else. So a universe seems by far more lush and vibrant in comparison, and they want a piece of that. It doesn’t help that while a Fringe and it’s universe usually never interact, two different Fringes of two different universes can, and usually will. It’s complicated as to how that happens, but Dimenost interact with their multiverse selves all the time. And some of those other selves have managed to sneak a peek into a universe before, and no doubt shared what they saw with all the other Dimenost in the multiverse. In fact, that’s why I’m surprised they didn’t know who I am because, long story short, my people have encountered them before, but that’s neither here nor there. Anyway, what this means is that now they all want to get into a universe, regardless of what universe they live around.”

“So…and maybe this is a stupid question…but why not let them?” Spike asked.

The Doctor sighed. “Unfortunately, I know from past experience, as well as the past experiences of several other time-aware races back in my universe that have had run-ins with the Dimenost, that us and them can’t really coexist without one causing harm for the other. We’re just too different. It’d be like trying to force an ice cube and an open fire together. Plus, the Dimenost see themselves as superior to pretty much everything else in existence, and will probably try and enslave everybody to prove it. And interaction with a fully formed Dimenost is…” the Doctor paused, looking for the right word, “…hazardous to one’s mental health. Physically touch one, and they can get inside your head and mess around in it, without any regard for privacy or sympathy or anything as they dredge up anything and everything in your head…even the stuff you might not want to remember. The shock of the experience can be very traumatizing even in just a brief exposure. So imagine what someone might be like after several lengthy exposures.”

Spike gulped. “They’d probably go crazy.”

The Doctor nodded solemnly. “And most would. I even know of members from my race who went mad after prolonged interaction with a Dimenost, and members of my race are no strangers to telepathy like that.” But then he grinned. “So lucky for us, the fix is easy. Even if the Dimenost open the tear wide enough to fit fully into this universe, they’re still tied to the Fringe. Why is complicated—it’s an advanced physics thing—but you close the tear, and they are all forced back where they belong and all’s good again. We just have to figure out what they’re doing to force the tear open bigger and stop them. It shouldn’t be anything my TARDIS can’t handle.”

“You mean that crazy box you arrived in?” Flitter asked incredulously, pointing upwards where the box presumably still hung in the library tree. “How the hay could that little box possibly do all of that?”

No sooner had she said that, a great donging sound rang out from above them, followed by a familiar “whirr” sound ringing out once before concluding with a solid “thump” that, though faint, could be felt from here, vibrating through the floor and up their hooves. They all gazed upwards at the roof of the room for a moment, in the direction of the sound.

“Well, speak of the devil, she’s ready! Perfect timing!” the Doctor declared cheerily, before looking back at the others and grinning playfully. “So how about I go and show you?”

Author's Note

Fillies and gentlecolts, the Dimenost. Fun fact; had actually first devised them for a totally different and unrelated story, but when that fell through, I figured they'd make for a good Doctor Whooves villain, and they wound up here.

Next chapter: the TARDIS revealed.