Their destination blazed in the night sky, far outshining the other stars. Steve gazed at it from the balcony that looped around Luna’s observatory, his horn quiescent, as he and Luna waited for Twilight to arrive with the professor. His magic had revealed all it could reveal from this location, the highest point in Canterlot.

The light itself he was perceiving had revealed precious little additional information, mostly from what it lacked. Twilight had fashioned a spectroscopic attachment for the telescope. It wasn’t all that hard to do; it had simply never occurred to a pony to do it. They now knew that starlight lacked any spectral lines whatsoever. The spectrum perfectly fit the black body radiation curve of a white-hot object, yet it lacked evidence of the ionized plasma that ought to exist at that temperature.

Earthly science had no good answer for how a cold object could put out so much light, never mind light that had the spectrum of a hot object. Obviously magic was involved, but that was hardly news.

Maybe stars had no material substance at all.

They would find out soon enough.

Steve returned his gaze to the princess. Luna was about a dozen feet away, contemplating the city below. She had been that way since she had raised the moon a few minutes ago.

He looked down at the city himself. Pools of light outlined the three-dimensional, mountain-hugging shape of the capitol. It was a pleasing effect. He wished he could point it out to Meg, but his wife had her own cross to bear that evening, preparing that changeling to stand in for her pegasus self. Tirek’s release was coming up fast.

Not that she had any interest in participating in this venture, but that wouldn’t have prevented her from seeing them off.

The tapping sound of approaching hoofsteps attracted his attention. In the combined light of the moon and their destination, he made out Twilight coming around the curve. Behind her was Arcane Scroll.

Luna was walking towards Steve. “Nopony else shall be joining us?” she asked the professor.

“Maybe on future journeys, but not this time.” Arcane looked at the unfamiliar unicorn next to Luna. “Not in light of the royal secrets that must be kept.”

Twilight stepped forward. “This is Steve, as you probably guessed, as a unicorn. If you could turn to the side, Steve…” She waited until he had done so. “Note his cutie mark. His special talent is highly relevant.”

The professor studied the cutie mark, a grid with ripples emanating from its center. “Yes… represents waves in space-time, does it not?”

“I believe so, yes.” Steve turned around, to face forward again.

“And you never had a cutie mark prior to becoming a pony?”

“Nope. And I still don’t have one when I’m human.”

“I wonder… just because it’s not visible doesn’t mean it’s not there. We know that a cutie mark is a magical projection onto the coat. Without magic, there can be no projection, and humans do appear to lack magic even when in our realm.”

True that may all be, but almost certainly academic. “Unfortunately, becoming a cutie-mark-bearing magical pony does not grant me magic when I am once more human. It’s an interesting hypothesis, but not, so far as I can see, testable.”

“You are right, of course. One of my students scanned you in the first class you held, and he found not a trace of magic.” He gazed up into the sky, his eyes unavoidably drawn to the unusually close star. “My gut tells me your cutie mark goes latent, but still present. Alas, I can think of no way to prove it.”

Steve wasn’t sure if it made a difference one way or the other. There was no observable difference, which was the point.

“Cutie marks are a mystery for another day,” Luna said. She, too, looked up at the star. “Let us remained focused on this mystery. Any reason we should not depart now?”

Meg wandered about the Oval Office, sticking her muzzle into every nook and cranny. It wasn’t furnished the way she remembered; it was more like a composite of the office as it had existed under the last few presidents.

“So what do you think?” A. K. Yearling asked. The changeling next to the author was paying close attention to Meg, ready to study her response.

Meg stopped and turned to face the author. “Your next book?” It was the obvious inference. “You’re going to set it on our world?” That prank in the forest must have seemed too good an idea to pass up. Having a book set in the human world would be good for sales in both realms.

Green fire erupted over the changeling. “It is a world ripe for plundering,” proclaimed the archvillain Ahuizotl. “This office is but a stepping stone!”

“Spoilers?” Meg asked rhetorically. “Never mind. I’m sure Daring Do defeats you in the end.”

He leaned in to her, sneering. “Can you afford to take that risk?”

“Can it,” Yearling said. “We don’t want the agents seeing you like this.”

The changeling reverted back to its true form. “Sorry. Got carried away.”

Meg resumed walking around the mock Oval Office. “So how are you going to explain this to them, without letting them in on your little secret?”

“With a half-truth, obviously. By the time the book is published, this set will have been deconstructed, transported, and reconstructed in my casino, where it will serve to promote the book.” She trotted over to the bust of Winston Churchill and tapped it. “All this ain’t cheap to recreate. Gotta get my money’s worth out of it.”

Indeed. Even ignoring the book tie-in, an Oval Office replica would be good for business. After all, Presidential Libraries have within them an Oval Office replica. Meg completed her circuit. It was quite impressive, considering all the ponies had to work with were photos and whatever else they could find, she assumed, on the internet.

Twilight would’ve been more than happy to have helped with that—once the need had been justified with that half-truth.

Sunset Shimmer appeared on the Presidential Seal on the carpet in front of the desk, as had become standard procedure in the real Oval Office. They had all been avoiding that spot for just that reason. Standing behind the mare were Agents Fowler and Reubens.

The two agents slowly turned around, taking in the replica presidential office. “Not bad…” Reubens said. “All to promote your next book inside your casino, right?”

“That’s right,” Yearling confirmed.

Twilight must have told them—which confirmed Yearling had first told that to Twilight.

But wait… no reaction to the changeling? That’s why they were here, after all, to get first-hand experience with one.

Fowler was looking at her strangely. Before Meg could ask why, her eyes shifted elsewhere. Meg followed them, and saw another Meg. She suppressed a groan. “I’m the real Meg; that’s the changeling.”

“Funny, I was about to say the same thing.”

It was also doing a good job of mimicking her emotional state. But they could sense that directly, right?

Sunset shrugged. “You wanted to experience changelings first-hoof? Here you go.”

“We sure did.” Fowler walked around the two orchid pegasi. “You look exactly alike… you sound alike… act alike…” Her eyes locked on to something. “You’re both carrying phones. I’m guessing only one is real?”

“That phone,” Meg said, pointing a hoof, “is a fake.”

Her confidence wavered. Just because it was a changeling copy didn’t mean it couldn’t work—right? Could it work? Could they copy the CPU and other electronics?

Fowler lowered herself in front of the disguised changeling, holding out a hand. “May I inspect your phone?”

The changeling hesitated for damning seconds.

“I’m guessing you can’t separate from it?”

In an eruption of green flame, it resumed its true form. “Not… easily.”

Reubens nodded. “That’s certainly useful to know.”

Fowler got back up on her feet. “Yeah. Humans are rarely without something they could hand over.”

“Not everything we’re carrying is necessarily copied,” the changeling countered.

“True,” she admitted, “but driver’s licenses, credit cards, passports, and stuff like that would likely be copied. Acquiring the originals would necessarily introduce risks of its own. Still, that’s a valid point.”

Sunset took a seat on a sofa. “As interesting as this is, it’s largely academic. Here, in this realm, there are spells to expose changelings; what they are or are not carrying does not matter. In your realm, changeling shape-shifting cannot work due to the conservation of mass and energy, assuming changelings can function at all. And if they can, those detection spells will probably still work.”

“In other words,” Reubens said, as he took a seat on the other sofa, “we should focus on Tirek’s release from Tartarus.”

Meg took a seat next to Sunset. It was time to come up with her rationale for being there, alongside “Common Ground.”

The first long-range teleport completed. Twilight’s eyes remained closed while she quickly ran down her checklist, verifying that everything was nominal. There was still air, that much was obvious. A faux gravitational field provided a sense of “down.” Another spell created the illusion of a floor that prevented them from “falling.” Temperature appeared stable.

“Incredible…”

The alicorn finally opened her eyes, reacting to Arcane Scroll’s utterance. Below them, their planet hung suspended in the void, a sight never before witnessed by a pony. It shimmered in the moonlight. No part of the planet was currently exposed to sunlight.

Steve sighed. “Just as well Meg isn’t with us.”

“Why would that be?” Luna asked. “It looks remarkably similar to pictures I’ve seen of your world from space.”

“Exactly. Another similarity or coincidence. It’s something that’s been rubbing her the wrong way.”

Twilight scrutinized the continents. All the clouds made that difficult, never mind the lack of proper illumination, but Luna was right: they did seem to line up with Earth’s North and South America. Not exactly, and maybe that was due to the cloud cover, but it was close enough.

She knew that Earth’s continents were shaped by billions of years of plate tectonics, driven by mantle currents, which were themselves largely powered by radioactive decay in the core of the planet—decay that could not operate in her own realm. So by what means did her world acquire the same, or at least similar, continents?

“We should teleport as soon as possible,” Steve said. “We are falling, despite appearances.”

There was no sign of visible movement, but that was only due to the many thousands of miles that separated them from their home.

“Yeah.” Twilight focused on their destination and prepared the spell for the next teleport. This one would go much farther.

“I regret not bringing my camera,” the professor said.

Right! The teleport could wait a few more seconds. “I got one.” She got out her phone from a saddlebag and snapped a picture of her their world.

“That’s a camera?”

It was probably her imagination, but she could swear the planet was ever so slightly larger. “I’ll show you after we teleport again.”

She refocused on the nearest and brightest star and again prepared the spell. Without needing any prompting, Luna poured in power at the right moment.

A brief flicker, and the planet was now a marble. Stars surrounded them, no longer competing with the planet’s luminosity, such as it was .

As Twilight went through her checklist, Steve made an observation: “I don’t see the Sun or Moon.”

The Sun, obviously not; it was nighttime. The Moon… well, the planet was being illuminated by moonlight. “I never considered the possibility that they wouldn’t be visible out here, but I guess it makes sense. The objects themselves do not glow; they are the source of the magic that produces the light, all over the world.”

Luna nodded. “I believe you are correct, Twilight.”

Arcane Scroll shook his head. “Fascinating. Maybe we should some day pay a visit to those two objects.”

“So long as I have a return ticket,” Luna muttered. If anypony else had heard those words besides Twilight, they did a good job of hiding it.

“Perhaps if I could make a suggestion,” Yearling said. “While none of this is, strictly speaking, any of my concern, I am a professional storyteller.”

She was sitting behind the Resolute Desk. A replica Resolute Desk. A replica that she commissioned and paid for. It still seemed odd and a bit disrespectful, but what was the point in bringing that up? Meg shot a glance at the Secret Service agents. They didn’t seem to be offended. For all Meg knew, you could buy one on the internet. “I’m listening,” she said. Anything to make some forward progress.

The author rested her front legs on the desk. “It’s quite simple, really. Meg, as a representative of the convention, needs a point of contact with the Equestrians. Twilight’s too busy to be that contact, being a princess and all.” She waved a hoof, forestalling the obvious objection. “Yes, we all know she’s quite involved, but that’s not the story we want to paint here, and a princess delegating stuff like this has the virtue of being credible.”

When no one spoke up, Yearling continued. “So there needs to be a point of contact on the Equestrian side as well. That contact is the pegasus, ‘Common Ground,’ played by the changeling. When Tirek is released, both point of contacts will be present to represent their respective interests. That provides the rationale for you two to be seen together.”

Her eyes surveyed the room. “What do you all think?”

Meg waited for anyone else to comment first. No one did. “Works for me, I guess.”

The changeling was less certain. “But what if Tirek tries to talk to me? I still don’t know how to handle that!”

And that was the giant wild card. “I, myself, don’t know how to handle that,” Meg confessed.

“At least you have talked to him,” Sunset pointed out. “The changeling hasn’t.”

“And we can’t read thoughts, just emotions.” The changeling tilted its head. “And yours right now…”

“Just… stop.” Meg had a decision to make. “It’s complicated, okay?”

Sunset looked at her. “Complicated, how?”

Should she tell them, or not? The changeling would not be alone with Tirek. She couldn’t imagine the centaur—soon-to-be-former centaur—bringing up the subject of his Tartarus breakout. Not in front of everyone else. Even if asked by the media, what reason could he have to throw under the bus the pony who had helped him?

On the other hoof—she looked down at the appendages in question—this may be the best opportunity she’d have to inform Sunset Shimmer of her alleged role in that breakout.

Then there was the author… explorer… she wasn’t quite sure what that mare was anymore.

Yearling’s eyes were upon her.

Meg sighed. She’s kept our secrets so far… She really ought to get Twilight’s permission first, for it was a royal secret, but it had started out as her secret. And as long as Twilight trusted Yearling as well…

“Fine. What I’m about to say is not to leave this room—not without the say-so of a princess anyway.” She addressed the human agents. “Can you keep this from the President?”

Reubens answered with a question of his own: “Would this information affect our ability to protect Tirek, never mind affect the national security of the United States?”

“I… don’t think so.” And if it turned out it did, should she keep it from them? For better or for worse, Tirek was about to become humanity’s problem. Was it right to potentially endanger her world in order to—potentially—spare Equestria a certain amount of embarrassment? As for the time travel part, Serrell already knew about that and had no desire to let it go public.

“Assuming that’s the case, then the answer is yes.”

It would have to suffice. She gathered her nerve.

“When I first saw Tirek, in his cell, he recognized me, called me ‘Common Ground.’ He actually seemed happy to see me.”

She let that sink in.

Yearling smirked. “Okay, didn’t see that twist coming.”

“Time travel?” Fowler tentatively suggested.

Yearling tilted her head at that.

“Maybe. I don’t know. But it gets better. Apparently, I helped to break him out of Tartarus a few years ago.”

Sunset snorted. “That’s absurd. No offense, Meg, but what could you possibly do to break somepony out of Tartarus?”

“Oh, none taken. You’re absolutely right. Tirek initially thought I was there to break him out again.” She looked Sunset straight into her eyes. “Then he realized that couldn’t be the case, because you weren’t there.”

“How…”

“He mentioned you by name. Then Twilight, Elaine, and these two showed up, and suddenly that conversation never happened.”

“You did seem a bit rattled,” Reubens said.

“You’re only telling me this now?”

“What was I supposed to say? I don’t even know we’re the ones who’ll do it—did it! Maybe whoever did had implanted false memories. I dunno.”

Sunset wasn’t impressed. “You had yet to visit Equestria, and I was… elsewhere. Who could have known about us to impersonate us or implant memories of us?”

“Somepony from our future, obviously.” Yearling was enjoying this too much. “Once you admit time travel, almost anything is possible.”

“That’s the problem,” Meg muttered. She spoke louder. “But not every possibility has the same probability. I’m afraid the most likely possibilities call for our direct involvement. We might not want those other possibilities to be the reality. Luna reminded me of that, in my dream.”

Fowler gasped. “Luna’s been in your dreams?”

“The novelty wears off, trust me.”

Sunset was still skeptical. “So when do we allegedly go back to break him out?—never mind how.”

“Not a clue,” Meg said. “I’m hoping to get that information from him.” She turned to the changeling. “And now you know everything I know.”

The sole planet in the realm was a dim spot, barely distinguishable from the stars. One of those stars was almost painfully bright against the blackness of space. Their hops would become smaller, now that they were closing in on it.

“Shouldn’t we be seeing multiple images of everything as their light circumnavigated this realm?” Arcane Scroll asked. “I mean, if what you say about curved space-time is correct.”

“We would see multiple images,” Steve replied, “except the stars are absorbing the light before it can circle around to its point of origin. They’re creating the illusion of an infinite realm.”

“That’s one possible explanation.” The professor was polite enough—or possibly unsure enough—to mention other possible explanations.

For example: space was finite, as the realm-measuring spell proved, but flat. There would be an impassable boundary—at least, impassable to the realm-measuring spell. More data was needed; all could agree on that.

Which was why they were here. Steve cast his modified realm-measuring spell on the star before them. The feedback came quickly. “Just over a light-second away,” Steve said. Though by far the strongest feedback yet, he couldn’t make better sense of it. It was beyond his skill or innate talent. It was up to Twilight, Luna, and the professor, once they reached their destination.

Luna was perplexed. “Why would they absorb light when they emit light of their own?”

“I don’t know. Evidently, no photon of starlight can circle the realm before being eliminated by some star’s magic.” Quite honestly, so far as he could see, starlight was purely cosmetic. At first, he thought it might have been the flip side of destroying energy, to keep the average density at the critical value. But that would require the light output to vary over time; instead, the stars’ luminosity stayed constant. It couldn’t work anyway; as every photon emitted would vanish before it could circle the realm, the net energy added by starlight was zero.

Using one of several instruments she had brought along, Twilight measured the star’s luminosity. “It’s hard to be sure, not knowing our precise distance, but it does appear that its brightness is increasing a bit faster than the inverse square law would suggest.”

In hindsight, Steve realized, that should have been predicted. “That’s because the star’s magic consumes some fraction of all light passing through its extended neighborhood, even the light it itself emits.” He realized that even if the photons didn’t endlessly circle the realm, they would nonetheless impart a slight curvature to whatever region they passed through. Starlight might be more than cosmetic after all. It’d require further research.

“If that’s the case…” She closed her eyes and reached out with her magic, analyzing the ambient magic that surrounded them. “Yes… there’s definitely a spell at work here, diffuse and weak to be sure…”

“But presumably operating over an immense volume,” Arcane Scroll said, “thereby having a substantial cumulative effect.” He tried to analyze the magic himself. “I’m afraid it’s too weak for me. I can barely sense anything at all.”

“I cannot sense much either,” Luna said, “but then neither of us is the Element of Magic.”

Steve didn’t bother trying. He knew he was out of his league here.

“It’s not like I’m detecting much myself,” Twilight said. “Certainly not enough to get a feel for what the spell is doing.” She looked towards the star. “I’m sure the spells will get stronger as we get closer.”

Meg’s phone rang.

Everyone looked at it, most of all the changeling. Probably wants to improve its emulation of it, she thought. Maybe a changeling can impersonate an inanimate object, but she doubted it could ever functionally mimic modern human technology.

She didn’t recognized the number. It could go to voice-mail. Most likely a scammer anyway.

“If they call again, you should answer it,” Reubens said.

“Huh?”

“I gave them your number, as you have the only working phone in this realm.”

“Well, Sunset’s—” The phone rang again.

Same number.

She took the call.

“Hello, Meg?”

The voice was unfamiliar. “Yes?”

“Could you please give your phone to Agent Reubens?”

What else could she do? She looked towards Sunset Shimmer, holding up the limb with the phone. “Could you…?”

“Sure, no problem.” With her magic, she extracted the phone from its holder and floated it over to the agent.

“Agent Reubens here.”

Everyone patiently waited for the call to finish. It didn’t take long.

“I’ll pass it along.”

Reubens held the phone out in Meg’s direction. Sunset returned the phone to its holder on the mare’s forelimb.

“Something happened?” Fowler asked.

Reubens grimmaced. “Yeah, you could say that. Senator Clarence Routledge will be in attendance for Tirek’s release. He wants to welcome Tirek’s return as a representative of the government.”

That name rang a bell; where had Meg heard it? It came to her. “Wasn’t he calling for a special prosecutor to investigate Serrell’s involvement with the imprisonment of humans in Tartarus?” All such calls had ceased after Tirek’s press conference.

“So, not a friend of Serrell?” Sunset rhetorically asked.

“I rather doubt it,” Meg said.

“And he can’t stop this Senator from attending?”

“That will be up to Princess Twilight,” Reubens replied, “as it is she who decides who may enter Equestria.”

Meg shook her head. “I doubt much good would come from denying him entry. He’d just use that to his political advantage.”

Yearling was still seated behind the replica presidential desk. “What’s in it for Routledge? He must have some motivation to publicly welcome Tirek like that.”

Meg shook her head. “You mean, beyond being on national television for the biggest event of the century? He probably wants to run for president himself someday. Assuming that associating himself with Tirek doesn’t backfire on him.”

“Precisely. Why take that risk?” Yearling gave her a thoughtful smile. “There must be more to it than meets the eye. Call it a writer’s hunch.”

“Where did it go?” Steve looked around in vain. The star was gone. “Did the teleport go wrong?”

“I rather doubt it,” Twilight said. “It was a short hop. There’s no way we could’ve overshoot like that.”

At their previous location, the star had been so bright that Luna had added a sunshade spell to their bubble. The other stars brightened as that spell was canceled. There was still no sign of their destination.

“Examine the ambient magic?” Arcane Scroll suggested.

“Good idea.” Twilight closed her eyes and lit up her horn. She flinched and desisted immediately. “We’re in the right area, all right. The spells are stronger than ever.” She looked around again. “So why don’t we see it?”

The view ahead slowly washed out, as if dawn was breaking. It got steadily brighter.

Arcane Scroll rubbed his muzzle in thought. “Perhaps starlight doesn’t come from the star itself, but from its spell operating in its vicinity. We must be drifting away from it.”

“We shouldn’t be drifting,” Twilight said. “We should be motionless with respect to it.”

“But the star isn’t motionless,” Luna said. “It wants to flee our world. Only my nightly efforts have brought it so close.”

“Could you use your magic to bring it closer to us right now? It can’t be far away.”

“I see no reason why not.”

Her horn lit up. The brightening reversed, and in a few seconds it was dark again. “It truly is close,” she said. “I’ve never had a star respond so fast.”

“But if it isn’t radiating light itself, how will we see it?” Steve asked.

Twilight’s horn lit up. “By illuminating it with light of our own, of course.”

She swept her horn about, trying to locate the star. Finally, something sparkled in the distance. Twilight locked on to it, narrowing the beam of light. The star erupted in coruscating colors, visibly approaching. But to know how far away it was, one first had to know how large it was, and they had no clue as to its size.

Luna was evidently thinking the same thing. “It’s probably best if I slowed it down, though I don’t think it’s very large.”

It appeared to be a foot across. Two feet. Three feet. Four feet.

“I’m getting a sense of distance now. It’s almost here.”

Nine feet. She further slowed its approach. Eleven feet. It drifted to a stop. It seemed to be about a dozen feet across. Its shape was hard to discern, as the light endlessly refracted about within the object, making it hard to see the actual surface.

“I wish Rarity were here,” Twilight said. “If I didn’t know better, I’d say this was a flawless gemstone of enormous size.”

“I suspect that’s exactly what it is,” Arcane Scroll said. “What better matrix for spells of this power and longevity?”

“Yeah… let me try something with my light spell…”

The flash and sparkle faded away. The surface was now visible, sort of. It did in fact look like a gemstone, one that was spherical, virtually transparent, apparently flawless, and had far too many facets to count. The object rested just outside their bubble, being held in place by Luna.

Arcane Scroll got as close as he could to it. “A simple analysis spell should identify the gemstone, assuming it isn’t something never before encountered.”

A few seconds later he had his answer. “I believe it is a diamond. It is definitely the source of the spells.”

“A diamond that big,” Steve said in awe. “And I’m guessing every star is like this. They had to have existed for as long as this realm has existed. Where did they come from? How were they enchanted?”

Arcane Scroll turned about to face the others. “The answers to those questions may best be answered by studying the object in front of us.” He smirked. “Even better, those questions haven’t been rendered unanswerable by the Discordian Era.” He looked up. “Not out here amongst the stars.”