Tension aboard Cygnus was thick. In one day, they'd gone from the shocking revelations of the original Coupling System Project to an assault by East Zogilia—one clearly intended to wipe out the legacy Cygnus' former time-displaced comrade had left behind.

It shouldn't have been too much of a threat, with the forces the Confederacy had arrayed around the lab. East Zogilia was unquestionably dangerous, but this deep in Confederacy territory, with several teams of Coupling Valiancers, an assault should've been unthinkable.

Doctor Elvira Conrad, standing behind her protege Nasu Mayuka's station on Cygnus' bridge, was forced to confront that unthinkable notion, and the means East Zogilia had used to make it thinkable.

"What's going on, Doctor Conrad?" Captain Kuramitsu asked, as calm as ever despite the situation. "What happened to our Couplers?"

"I'm not sure," she admitted unhappily, staring intently at the readouts on Mayuka's display. Outside, the standard Valiancers on both sides continued to rip and tear at each other, and somewhere much closer than she was comfortable with Dio dueled with the strange Valiancer Evgeny Kedar had appeared in. "There's some kind of interference, but I've never seen anything like this!"

"And why is Premier Kedar himself here?" Commander Kleinbeck muttered. "He said something about Watase—why should he care?"

Elvira didn't know, but she was sure Kedar's Valiancer was somehow the key to what was going on. Dio was putting up a good fight against it, exchanging Nectar rifle fire with the strange, heavyset unit, but for an ungainly machine piloted by a geriatric politician, it was performing disturbingly well.

"Look at these values, Elvira-san," Mayuka said, drawing her attention to a purely tactical section of the display. "The acceleration rate of that Valiancer... That shouldn't be possible outside of a Coupling!"

The scientist didn't know the mechanical details of Valiancers very well, but certain parameters were so closely tied to the Coupling system that she'd learned them by heart years before. Acceleration was one of them, with the physics-stretching speed of Coupling Valiancers being one of their greatest strengths.

"It's like it is a Coupling Valiancer," Elvira muttered, more to herself than anyone else. "But there's still no sign of any partner, and no Coupling could be formed on either side with this interference anyway! Unless he's a cyborg or some ridiculous thing like that..."

With a rumble that shook the ship, a stray blast from Kedar's immensely powerful weapons slammed into Cygnus' Nectar Curtain. "Doctor Conrad," Kleinbeck called over the din, "we need a solution! If we don't get the Coupling systems back online—!"

"I'm working on it!"

Outside, Elvira could see Confederacy Valiancers going down, and the larger explosions of ships here and there. Dio was keeping Kedar mostly occupied, and Fromm was putting up a good fight despite what had to be a near-incapacitating headache, but even she could tell they were losing ground fast.

Think! she ordered herself. One Valiancer, acting like it's Coupled with no Buddy in sight, interference preventing Coupling entirely... Doctor Hahn's up to something new, and the key has to be in there, but... Wait. The SAC theory? But we never pursued it because of the dangers! If it failed—

"Elvira-san," Mayuka said, looking up at her, "what about the SAC theory?" Before Elvira could recover from the surprise that Mayuka was following her train of thought and provide the obvious counterpoint, the younger woman continued, "I know we didn't pursue it, but Doctor Hahn wouldn't care about the danger—"

Elvira swore. "Of course he wouldn't... Captain, we may have figured out what's going on!"

"What is it, Doctor? And can you do anything about it?"

She bit her lip. "Well, a couple of years ago, our experiments suggested an alternate application of the Coupling system, what we labeled Stand Alone—"

Before Elvira could get any further, the entire ship was abruptly rocked to one side, and she was nearly thrown from her feet. At the same time, blinding yellow light erupted somewhere beyond the starboard viewports.

What the—I know I've seen that before!

"Singularity detected one hundred meters to starboard!" Framboise called out. "Origin unknown!"

As if we ever know what causes—now what?! Mayuka's displays had suddenly lit up with additional telemetry, and even as Elvira stared a data stream started pouring through. Completely ignoring what should have been secure firewalls, the transmission promptly bootstrapped itself through Cygnus's systems and continued on to Bradyon NX.

"Incoming transmission, bypassing our security!" Mayuka yelped. "Source is—wait, Captain, this is—!"

"Sorry to be so abrupt," a voice said over the comm systems. "But we're in a bit of a hurry. Elvira-san, we need to talk, fast!"

What the hell is going on here?! Dio raged inwardly, firing off a Nectar rifle shot at Kedar, only to see it dodged with contemptuous ease. Out of the corner of his eye, he saw another Confederacy Valiancer fall to a missile barrage from one of East Zogilia's submarines, and he cursed under his breath.

He'd hated the Coupling system for years, but he had to admit that it was one of the greatest advantages that the Confederacy had. Without it—especially after having had five years to grow accustomed to relying on it—they just weren't able to hold back the East Zogilian assault.

Dio heard a cackle as Kedar fired a massive blast past him, and an explosion a moment later signified the demise of one of Cygnus' sister ships, the flying battleship going up with a big enough bang to send several Valiancers tumbling out of control. By himself, Kedar was posing possibly the greatest threat on the entire battlefield, with his powerful, inexplicably mobile Valiancer.

Swearing with increasing frequency, volume, and vileness, Dio snapped off another Nectar blast and spun away, darting away from the embroiled forces. For whatever reason, Kedar seemed focused on Aoba—of all people—so if the old man happened to know that they'd once been partners, maybe...

A mocking laugh over the radio seemed to confirm the theory. "Yes, that's right! Run, just like Watase Aoba ran back to the past! Without him, you're nothing but an insect, to be squashed at my leisure!"

The energy blast that nearly vaporized Bradyon at least served to prove Kedar was indeed chasing him. As he threw the Valiancer into a wild corkscrew, though, Dio knew he couldn't keep it up forever. Sooner or later, Kedar would either succeed in shooting him down, or would get bored and return to the main battle. If Elvira couldn't figure out how to compensate for the interference in the Coupling systems by then—

Bright yellow light erupted into being without any warning at all. It was some distance behind Dio and his opponent—somewhere closer to Cygnus, he thought—but it was enough to distract them both; when he turned to look, he saw Kedar, too, spinning around to face the source of the interruption.

What the hell—that's a singularity! Dio thought, incredulous. Why would—

Alarms sounded in Bradyon's cockpit. At first he thought it was related to the singularity, but when he glanced at his displays he found them in total disarray; from the look of it, something was forcibly rewriting part of Bradyon's operating system on the fly, completely ignoring the Valiancer's firewalls.

After that brief glance, Dio found himself having to fight Bradyon's controls just to stay airborne. The in-flight alterations to the OS were wreaking havoc on flight systems; if Kedar had been less distracted, he was quite sure he would've died in that moment.

"A time tunnel?!" Kedar rasped incredulously. "It can't be—you—?!"

Dio didn't know what the old man was talking about, and didn't have time to try and figure it out. Abruptly, his displays stabilized, showing first SOFTWARE UPDATE COMPLETE; then, STAND ALONE MODE READY.

Stand Alone Mode? What—

"Dio!" Elvira called, sounding thoroughly shell-shocked. "Activate the new protocol, now! Link with Bradyon!"

He had no idea what was going on anymore. It was all coming too fast, with no explanation whatsoever. Without time to even try and make sense of it, he could only act on instinct. Calling to mind a command he hadn't given in five years, he said, "Connective, Bradyon!"

It was completely unlike linking with Aoba. There was no sense of any kind of intelligence on the other side, no bleed-over of emotion or reflex; only a sudden flood of tactical information going right into his mind, and a sense of time slowing down.

Along with a sound of anguish from Evgeny Kedar, whose Valiancer jerked and bobbed in the air, momentarily out of control. The cry shook Dio out of his own immobility, and he rushed right for Kedar's Valiancer, reveling in the physics-defying speed he hadn't felt in five years. Whipping out Bradyon's sword, he slashed through Kedar's right arm in a dash that took him through and past before the Zogilian could recover.

"That's got it!" a voice called triumphantly. "We were right!"

"It's you," Kedar gasped out, his machine stabilizing, despite the sparking from its severed shoulder joint. "You've come back... after all these years, you bastard, you're back—!"

"Aoba...?" Dio whispered in utter disbelief. Bringing Bradyon around for another pass, he finally saw exactly what was emerging from the time tunnel: in the fading glow of the dissipating singularity, Luxon NX and Karura hovered, looking no more worn than they had five years before.

A window sprang open on his display, showing a face he hadn't seen in person in just as many years—but had seen, looking just as it did now, less than an hour before, in recorded form. Barely visible behind him, a glimpse of someone else from that same video. "Yo, Dio," Watase Aoba said cheerily. "Long time no see, siscon bastard!"

"What—you—how?!" Dio demanded, stumbling over his words.

"Watase Aoba!" Kedar shouted, before Aoba could reply. "Seventy years, I've thought I could never get my revenge—now, here you are, right where I can finish you!" Improbably, the old man laughed delightedly. "And here I thought I was going to have to settle just for destroying your legacy!"

"Not happening, Bizon," Aoba replied, his face suddenly assuming a deadly calm that Dio had never before seen from him. "If you thought we came here just to let you blast us—whoa!" Luxon dashed sideways, shoving Karura out of the path of a Nectar cannon blast from Kedar, and Aoba tsked. "Right, no time for reunions. Dio, we're about to try something kinda reckless, okay?"

Dio surprised himself by chuckling. "Like 'reckless' ever stopped you before?"

Aoba grinned. "You know it. Hina, you ready?"

"Of course, Aoba." The girl Dio only really knew from the memories he'd seen from Aoba appeared on Bradyon's display now, and said in tandem with him, "Connective, Dio!"

Dio didn't hesitate. "Acception!"

It was at least as different from his past experiences as his brief Coupling with Bradyon itself. Instead of just one mind, he felt himself connecting with two—two which operated on such a close wavelength that he could only barely tell them apart. In that instant, he could see the entire battlefield—everything in the view of Luxon, Bradyon, or Karura, the link reported to him.

If he hadn't been so experienced with the insanity that was Watase Aoba with a Coupling system, Dio would've been overwhelmed by sheer sensory overload. As it was, he gritted his teeth against the strain and held on; the initial shock passed quickly enough for him to notice the spheres of cast-off energy that erupted from their respective Valiancers, converged, and merged in the same way he'd seen five years before.

This time there was no giant Nectar cannon shooting at them, but it was still enough to provoke a garbled shout from Kedar. "You... all these years, and you still mock me, Watase Aoba!"

Beneath his voice, Dio heard someone else yelling; someone on a dedicated link to Kedar, he supposed. "Not possible! You... whoever you really are, you can't possibly have done something like this! Not with the resources of your time! Not like this!"

"Doctor Hahn, I presume," Aoba said dryly. He shook his head, and looked out the display at Dio. "Let's wrap this up, Dio!"

"Right." Kedar's Valiancer was missing an arm, but obviously was still combat-capable—and there were still plenty of other East Zogilian forces around. Their plan with the Coupling interference seemed to have prevented them from deploying Coupling Valiancers of their own, but that was the only handicap they really had.

If Dio was right, though, Aoba's stunning reappearance was going to make the difference.

"Watase Aoba is mine," Kedar snarled over the radio. "Disable Hina if you must, but do not kill her, either! The other boy... shoot him down!"

Dio took that as his cue to move, turning away from Kedar to face the regular East Zogilians that rushed to obey the Premier's command. The first to reach him, the pilot of a commander's Alsiel, would probably have posed a significant threat to him just a few minutes before; now, with the power of the Coupling system backing him again, he dodged to the side of the Zogilian's cannon fire, darted forward, and sliced him in half with one smooth stroke.

A similar fate befell the team of two Ogres and a Krishna that tried following their commander's lead, and then Dio was among the vanguard.

Through the Coupling system, he could mostly follow Aoba and his partner's actions at the same time. When Kedar finally threw his bulky unit into motion again, they split to either side in a perfectly-coordinated pincer—against a team of Zogilian regulars who'd gone for Cygnus while everyone else was distracted. Dio heard a yelp over the radio at the sudden motion—from Aoba's passenger, he thought—but the Zogilians were probably the more surprised.

They'd likely counted on Kedar's presence preventing Coupling operation. Even if they'd been prepared for the alternative, though, they obviously weren't prepared for Watase Aoba.

He hasn't lost his touch, Dio thought, watching with a corner of his mind as Luxon drew both of its swords and dove into the fray. A slash here, a whirling chop there; Valiancer parts went flying, and when an Alsiel turned the Nectar rifle it was carrying on him, he was suddenly somewhere else. The shot went wild, followed by the rifle and then the top half of the Alsiel when Karura blurred around behind it and tore it apart.

The unexpected tactic was both wreaking havoc on the Zogilians and leaving Kedar obviously scrambling to catch up. Forced into a chase rather than the direct clash he'd clearly expected, the old man swore bitterly. "After seventy years, you finally reappear, Aoba—and now you won't even face me?!"

"Some of us have better things to do than nurse old grudges, Bizon," Aoba responded calmly; he didn't even sound winded, a far cry from the excitable youth Dio remembered. "But if you really want it—come and get it!"

He and Karura whirled around together, their rifles suddenly pointed at Kedar. It was the Premier's turn to pull away sharply, his odd variant of the Coupling system allowing him to dodge Luxon's Nectar fire, yet not quick managing to avoid Karura's shell-firing weapon.

Armor-piercing rounds left deep dents even in Kedar's heavy armor as he pulled away. "I'm going to kill you, Aoba," he growled. "I will kill you, and level the entire island, along with your precious Swan! And Hina—what I'm going to do to you will make you wish you'd been obedient all those years—gah!"

Pursued by Aoba and Karura's fire, Kedar's Valiancer stuttered in the air, the bright light on its fuselage fading. For an instant, Dio wondered why—then realized that, modified though it may have been, there was one weakness to the Coupling system Kedar must still have been subject to.

"Why is it shutting down?!" Kedar demanded. "Now is not the time for this!"

Again, there was that other voice in the background. "Even in Stand Alone Mode, there's an inherent time limit," the voice said, sounding harried. "If you go past it, the consequences—"

"I don't care! Aoba is finally here, and I will not let him get away again!"

"You're out of time anyway! Look at the radar, why don't you!"

Dio blinked, and followed the instruction himself. There were, on close inspection, a rather large number of new blips heading for the battlefield, sweeping down to engage the East Zogilians' north flank. "Cygnus," he called, "are you seeing this?"

He got an answer, but not from Cygnus. "Attention, Confederacy forces. This is Alfried Gallant; we are coming to your assistance."

"Much appreciated, Commander Gallant," Captain Kuramitsu replied, sounding as calm as ever despite the heavy losses of the day. "We've already received some unexpected reinforcements, but more is always welcome."

"...So I see, Captain. I hope you'll be allowed to explain it, later."

A loud, angry curse erupted from Kedar's Valiancer, obscene enough to make Dio wince. "So," he continued after, sounding very bitter. "You live another day, Watase Aoba. You'll wish you hadn't... All East Zogilian forces, pull back!"

"Let them go," Kuramitsu instructed, just before Dio could try and give chase. "Protecting the lab is the top priority right now."

"Thank you for that, Captain," Aoba said, sighing; he seemed to be watching Kedar flee with a very tired expression. "I don't know if our backups survived to the present day, but if they did, it'd be a big help; there's only so much data we could fit in the Valiancers."

"I'm sure, Ensign—or should I say, Doctor?" There was a definite smile in Kuramitsu's voice. "Would you please join us aboard? Your wife has clearance too, of course; I see no reason to be concerned about her loyalties at this point."

"Thank you," Aoba said again. "We'll be aboard shortly." He looked back up out of Dio's display, grinning again. "Shall we, Dio? We've got a lot to talk about."

Dio nodded, unable to trust himself to speak now that the crisis was past. "A lot" is an understatement. How... how are you even here? And... why?

Déjà vu was really the only way to describe how Dio felt, setting Bradyon down in Cygnus' hangar beside Luxon. Five years on, and it still felt more natural than the many solo landings he'd made since.

The illusion was quickly shattered, though. Landings five years ago hadn't included half the crew showing up in the hangar—and the Zogilian Coupling Valiancer information exchanges with Alfried Gallant had named as Karura had never been aboard Cygnus at all, nor its pilot. For that matter, Luxon NX never actually landed here, either...

He'd spent five years wondering if he'd truly made the right choice that day. It looked like he was about to find out.

Karura's pilot was the first to come down from her cockpit. Dio twitched at the sight of her Zogilian flightsuit; intellectually, he knew that this pilot was no enemy, but old habits died hard. Even after five years of occasional joint operations with Alfried Gallant's forces, Zogilians made him uneasy. That unease faded quickly, though, when she pulled off her helmet, revealing a face that Dio remembered very well, if only through someone else's memories.

Among the assembled Cygnus crew, though Kleinbeck looked about as uncomfortable as Dio had, Kuramitsu favored the young woman with a friendly smile. "So, at last we meet the mystery girl our lost pilot caused so much trouble over. Welcome aboard Cygnus... Yumihara Hina, I presume?"

"Watase Hina, actually," she corrected, offering a salute. "Doctor, if you want to get technical. Captain Kuramitsu, I take it? My husband will be down shortly; things in Luxon's cockpit are a bit cramped right now."

Dio thought he heard a strangled noise of distress from the throng of crew; he couldn't see where it came from, but he was pretty sure he knew. There was only one person aboard who would react like that to someone calling Aoba their husband, after all.

He had no time to spare for Mayuka, though, as at that moment Luxon NX's hatch cracked open, admitting two figures. The first one down wore a familiar—if somewhat worse for wear—Confederacy flightsuit; the other... Dio found himself suppressing a smile, to his own surprise. The flightsuit the girl was wearing might've looked twin to Hina's in cut and style, but it clearly had needed a fair bit of work for it to fit its current owner.

"Hey, guys," the boy—no, Dio corrected himself, man; to his shock, the other pilot now looked older than he was—said cheerfully, pulling off his helmet. "So... long time no see?"

"Doctor Watase, I presume." Kuramitsu shook his head. "It has been a long time, yes—longer for you than for us, I'd guess. Welcome back."

"It's good to be back. Though I bet you've got a couple of million questions for us, even with the message we left. Oh, yeah." Aoba stepped to one side, letting them have a better look at his companion, now taking off her own helmet. "Let me introduce our loyal assistant, Intern Watase Tsubasa. My sister. Tsubasa, these are the guys I've been talking about all these years: the crew of the good ship Cygnus, under Captain Kuramitsu Gengo and Commander Lene Kleinbeck. And this," he added, turning to look at one person in particular, "is my old partner, Junyou Dio Weinberg."

Watase Tsubasa tucked her helmet under her arm and scratched the back of her head with her free hand. "Um... hi. Aoba's told me a lot about you all. It's, ah, nice to meet you all..."

"The feeling is mutual, Watase-san," Kuramitsu said graciously, giving the girl—Dio realized with a start that Aoba's "little" sister was about his own age—a short bow. "Any of Aoba-kun's family is, of course, very welcome here. After all," he said with a wry smile, "you all did just completely turn the tide of a losing battle for us. It would be ungracious of us not to welcome you."

"Even if we have no idea how you're even here!" Elvira Conrad broke in, unable to contain herself any longer. "The Coupling system is only supposed to even work on elementary particles—singularity or not, the idea that that was actually a time tunnel is just—and how did you even do that on purpose?!"

Aoba laughed. "One thing at a time, Elvira-san. I know we've got a lot to talk about. But first..." He turned to face Dio again, the humor fading. "Yo, siscon bastard. Sorry we're late, but we wanted to avoid creating a fifth Iteration. Our first test with an unmanned drone wasn't very precise, and arriving before the events it recorded would've invoked the Temporal Observer Effect..."

Dio raised a hand. "Stop, you're making my head hurt. This is worse than the time you convinced me to go along with chasing Hina in Skyknight and Firebrand..." He trailed off, and blinked away what had to be fatigue-induced tears. "You're really here, aren't you."

"We are, Dio. And this time, we're all here to stay." There was a steady maturity in Aoba's eyes, one Dio was sure he hadn't had five years before. "Our drone test told us a lot about the current situation, and we've got some ideas to turn the tide. Elvira-san, we've got a lot to discuss—you might want to have painkiller on hand, it makes our heads hurt, and we invented it. But first..."

Aoba walked toward the assembled Cygnus crew, waving at Anessa and exchanging a handshake with Fromm as he went. He stopped, not to Dio's surprise, in front of Nasu Mayuka, who was visibly choking back tears. Smiling gently, he held out a hand to her.

"Hi, Mayuka-chan. Sorry I was gone so long."

Mayuka swallowed hard, and hesitantly gripped the offered hand. "It's... it's okay, Aoba-san," she whispered. "I'm just... so glad you're alive..." She bit her lip, stood still a moment longer—then threw herself at him, sobbing.

Dio quickly looked over at Hina, expecting Aoba's wife to be upset. Instead, though, all he saw was a small, sad smile, and after a moment he realized why. They used themselves as the initial test subjects for the system. If there's any marriage that's already been tested as far as can be, it's theirs—and she's probably seen his memories of Mayuka, too. She knows as well as I do that Mayuka's not a threat—and Aoba being Aoba, he'd want to be sure she's okay.

He turned his attention then to Kleinbeck, but she only shook her head, apparently willing to let the lapse in discipline slide. Given that she was looking more than a little shell-shocked herself, he supposed it wasn't too surprising.

Something drew his attention back to the Valiancers then, and his gaze fell on Watase Tsubasa. Mostly forgotten in the emotional reunion, the young woman looked more uncomfortable than anyone, very obviously feeling out of place. She still stood by Luxon, fidgeting nervously.

Hard to blame her. She's the only true civilian on a ship of military personnel, and unlike Aoba or Hina she's never been to this time period before. ...Why is she even here, I wonder?

At length, Aoba pulled back from Mayuka, patted her gently on the shoulder, and turned back to the officers. "Well. I guess it's time to do some explaining? If you'll give us time to change out of these flightsuits, Elvira-san, we can take this conversation to the Captain's office." He grinned. "Hina and I will save the math for the lab, after."

Several hurried calls to higher authority later, granting their time-displaced guests provisional security clearance, a meeting was indeed called in Captain Kuramitsu's office, during which both sides brought each other up to speed on relative recent events. Much consternation was created on either end; probably the only thing about the day that had gone as Dio might've expected.

"Whew," Aoba said, shaking his head, when Kuramitsu had finished outlining the highlights of the last five years of war. Like his wife and his sister, he'd traded his flightsuit for a labcoat, a look Dio still found very strange on him "I knew from what Hina told me that Bizon was the type to hold a grudge, but over seventy years? That's dedication."

"I'm wondering how in the world he survived to get this far," Elvira said, rubbing her forehead. "I thought you and Doctor—er..."

"Call me Hina," Aoba's wife advised with smile. "Otherwise we both try to talk."

"Right. Hina." Elvira closed her eyes for a moment, obviously fighting off a headache. "Anyway. Didn't you two kill that guy before Dio sent you back? I've seen the footage from Bradyon's flight recorder, and he looked pretty dead to me."

Dio winced. He didn't need recordings to remember that moment; a human body being hit by a Valiancer-sized rifle was messy enough to be hard to forget.

"That was the Iteration IV Bizon," Aoba told her, stuffing his hands in labcoat pockets. He looked for all the world like a professor preparing a lecture, as bizarre as that was coming from him. "Evgeny Kedar, if my math is right, is a remnant from Iteration III."

"Iterations?" Kuramitsu asked, tilting his head. Before Aoba could reply, he raised a hand, smiling ruefully. "Is this going to give me a headache, Aoba-kun?"

"Doctor Hill will probably have it worse," Hina opined. "It's harder if you actually know some of the math."

"Simple version, then." Now Aoba assumed what was unquestionably a lecturing pose. "According to the model of the timestream we've worked out, there is only a single timeline—single, but mutable. The trick is what we call the Temporal Observer Effect: any change remains valid so long as nothing prior to it is changed, even if the original cause is an event from further down the timestream.

"Our model of the time-loops surrounding Hina boils down to four 'iterations'. Well, technically a lot more, but most of those were variations of Iteration III... Anyway." He raised one finger. "Iteration I: Hina and I develop the Coupling system on our own, without any temporal interference. Hina gets sent forward during the original test, and more or less plays out my role from the iteration we all know personally."

"You mean..." Dio frowned. "That would mean Hina was the pilot of Luxon the 'first' time around?"

"Right. Until the Battle of Alaska, when... something happened we're not actually sure of, causing the singularity that linked back to our high school days." Aoba extended a second finger. "That begins Iteration II. Bizon shows up trying to kill Hina, I get caught in the crossfire, the time tunnel opens and sends her to the point Victor Ryazan adopts her, and I become Luxon's pilot." A third finger. "Events proceed as in 'our' timeline, up until Alaska, when Hina and Bizon get thrown back as in Iteration I. Begin Iteration III: Bizon comes to kill me. Events proceed according to that outline, give or take a few details, for... longer than we care to think about."

"Until," Hina said, picking up the thread, "Aoba and Dio succeed in Coupling with Skyknight and Firebrand." She nodded to Dio. "Seeing Aoba's memories then—that's why you chose to help him chase after me in the time-tunnel, right?"

He nodded back. "I honestly didn't believe in the time travel stuff until then," he admitted. "But when I saw that Aoba really did honestly believe everything he'd told us, and the time tunnel more or less proved it..."

Dio left it at that, not quite willing to admit why he'd acted so. That, having lost his mother to an attack he failed to stop—and almost lost his sister at the same time—he hadn't been willing to let Aoba go through the same, if he could possibly do anything about it.

Somehow, actually admitting that aloud felt like it would be conceding some kind of point to Aoba, and even after all these years that wasn't something he could do easily.

From the smile on Aoba's face, he had the feeling the crybaby-turned-physicist knew it perfectly well anyway.

If he did, though, Aoba didn't push it, instead continuing, "We did kill Bizon then, yes—but the change in timing of our fall down the time-tunnel changed our arrival point, too. We arrived after Iteration III Bizon's attack, so the attack still happened—and that Bizon apparently survived his Valiancer's destruction."

"And from there, your message told us what happened." Elvira sighed. "Ugh, temporal mechanics give me a headache... Oh, thank you, Captain." She took the painkiller and glass of water Kuramitsu wordlessly set on his desk, swallowed, and turned back to their guests. "So this... Temporal Observer Effect is why you didn't show up until now?"

"Right," Hina confirmed. "We'd sent an unmanned drone ahead to get final data on calculating the trip, and we didn't want to risk creating yet another Iteration by altering the events we saw in its report. Just after the battle began was the closest we thought we could risk."

"Well, I don't think anyone on our side is going to complain about it," Kuramitsu told her, smiling. "Late or not, you did save the day—and I suspect you've got a wealth of data for Doctor Conrad, if the tricks you pulled on arrival are any indication. Having you with us is far more than anything we could've expected to gain from that old lab."

Dio nodded in agreement. Just breaking the Coupling interference Kedar had caused had been an immense help; the strange triple-Coupling even more. The implications of what might be possible beyond that were staggering. And since the two inventors of the Coupling system were also veterans of using it in combat, they had a much better perspective than even Elvira.

But it still leaves one question. I don't even want to think about the math in their timeline model, but their "simple" version does make sense. Even so...

"But why, Aoba?" he found himself asking, before he could stop. "You were finally back where you belonged. Back with your family, in a time before this war broke out. Why would you come back here—especially since, from what you're saying, this must be a one-way trip?"

More, come to think of it, what was his sister here for? Watase Tsubasa, Dio had noticed, had said almost nothing since arriving, letting her brother and sister-in-law do all the talking. Obviously, she wasn't anywhere near as comfortable as they were with what had been done.

Aoba took his time replying, rather than uttering something flippant the way he probably would have in the past; Dio found that as unnerving as anything else. "...There wasn't anything left for me back there, really," he said at last. "Or Hina. Dio, from our point of view it's been eight years since we left this time; things have changed. My mother died before we perfected the Coupling system, and honestly, I had closer ties to people in this time than I ever did to those in my own. And Hina..."

"Technically, I'm like Bizon," Hina said quietly. "I'm from a no-longer-valid iteration of the timeline. My parents were still alive—but they had another Hina, one growing up normally. After I stopped looping, Aoba's family was the only one I really had. When his mother died, and Tsubasa got so involved in the Coupling project..."

"It was easier this way, I guess." Tsubasa's contribution was quiet, hesitant; but Dio got the impression she at least wanted to make clear she was there by her own decision. "I didn't have anybody left, and Aoba said he had friends here... And honestly, can you get a bigger career boost than being part of something like this?"

Dio grimaced, but didn't pursue the point any further. This wasn't what I had in mind, when I pushed them back into the time-tunnel. I thought they'd earned their peace, away from this war... but it's their decision to make. Anyway, what would I have done, if I'd lost the rest of my family, and had a chance to go somewhere I knew I had friends?

It wasn't like he was upset that Aoba was back, after all. He had no intention of admitting it, but he didn't really think it was a bad thing, at all.

Kuramitsu gazed at them silently for a time, seeming to weigh the matter himself. As usual, his thoughts were difficult to gauge, but in the end, he shrugged, leaned back in his chair, and smiled. "I don't know that I'd have made the same choice myself, Doctors, but speaking as someone who's getting very tired of this war, I'm glad you're here. Any assistance you give us, on the battlefield or in the lab, will be much appreciated. Ah... that is, if you're intending to stay with the military?"

Aoba and Hina exchanged a quick glance. "I think some kind of civilian contractor status might be best, if we can swing it," the former said. "Not that I really minded being a soldier or anything, but we're going to be doing at least as much pure science as fighting, maybe more, so the distinction could get kinda blurry."

"I suspect something can be worked out. In the meantime, once again, welcome back, Aoba-kun. I'd suggest you get some rest, for the time being." Kuramitsu was still smiling, but his eyes had noticeably sobered. "It's hard to believe Kedar is doing all this out of such a petty grudge, but whatever his reasons, I doubt he'll give up now. We're all going to be busy, when his forces have regrouped."

As glad as he was to have Aoba around again—not that he was inclined to admit it, even under the most brutal torture—Dio found himself needing an escape after the discussion moved to Cygnus' onboard lab. Pure Coupling theory had always been hard on his brain, however good he'd proven at practical application; the concepts and math being thrown around now were completely over his head.

Aoba went and became a scientist, he thought, making his way to the hangar. That's... utterly mind-boggling. When did he get so smart?

Probably, Dio mused, when he found his new partner. It was obvious Hina was good for Aoba on more levels than just emotional; even their Emphatier waveforms were a perfect match, even more so than Dio's had been.

Which, he had to admit, if only to himself, was part of why he was feeling so lost. Aoba was finally back—but he wasn't really Dio's partner anymore. Three years more had passed for the scientist than the soldier, and under very different conditions. Clearly, when they did enter the battlefield once again, even with the experimental three-way Coupling, Hina would be Aoba's main partner now.

Dio could live with that. He'd spent five years without his partner—friend, if he were forced to be completely truthful—around at all; this was just one more adjustment. It only made it a little harder.

Reaching the hangar, he was surprised out of his contemplation by the discovery that he wasn't the only non-mechanic who'd dropped by. Standing on the catwalk in front of Luxon NX, Watase Tsubasa leaned on the railing, looking completely lost in thought.

Curious, Dio cautiously approached Aoba's time-lost sister. "Miss Watase?" he said. "I'd have thought you'd be in the lab, with Aoba and Hina."

She jerked, startled. "Eh?! Oh... Weinberg-san, right?" Tsubasa shrugged, turning her attention back to her brother's Valiancer. "I'm still an intern; the kind of math they were getting into with Doctor Conrad was making my head hurt. When they're ready for more experiments, they'll call me in."

"I'm glad it's not just me." Turning to lean against the railing himself, a discrete couple of meters away, Dio ruefully shook his head. "Back when I last knew Aoba, he wouldn't have understood any of this, either. Most of the breakthroughs we made with him were because he was too ignorant to know what was impossible. Hearing him talk like Doctor Conrad is unnerving."

"You're telling me? I grew up with the guy." Tsubasa snorted. "One day he's the same old, always late for school, barely keeping his grades up brother of mine, who probably never talked to a girl outside the family in his life. Then a giant robot attacks out of nowhere, Aoba comes home with a girl, and he hits the books like he's trying to be the next Hawking. It was so weird I actually thought time travel made it make sense!"

Dio found himself nodding. "Aoba's like that. He's always doing crazy things—and it just makes it harder to take when he's right about something. He was only on Cygnus a few weeks, but he gave us plenty of headaches doing the impossible." Looking over at Luxon NX, he couldn't help but remember the very first impossibility: Aoba's appearance out of thin air in the original Luxon's cockpit.

We should've known something weird was going on from the very start, he thought. Lack of records and his crazy story could've meant he was a spy—a really bad spy—but there really wasn't any logical way he could've gotten into the cockpit. Not when it was covered in rubble.

Off to his right, Tsubasa sighed. "So... this really is seventy years in the future, huh? Even after everything, it's hard to believe Aoba really was telling the truth about his crazy time travel adventure."

"It wasn't any easier for us to believe he was from the past," Dio told her, smiling reluctantly at the memory. "Of course, I always thought he was too stupid to be a spy, but honestly it seemed more likely he'd taken one too many hits to the head—especially since Doctor Conrad was so sure time travel on anything but particle-level was impossible."

"Aoba always seemed like an idiot back then," she said, rolling her eyes. "If it weren't for me, he never would've gotten to school on time. Time travel? Ending up as some kind of hotshot ace pilot in the future? If he hadn't had a giant robot, I never would've believed it when he finally got around to telling me. ...Actually, I never really did believe it, until we accidentally sent Hina to the future in that first experiment." Tsubasa shot him a sidelong glance, one eyebrow raised. "So? How he'd convince you guys he wasn't crazy? That kind of crazy, I mean?"

Dio surprised himself with a chuckle. Watase Tsubasa, he was discovering, was very easy to talk to—their shared source of exasperation was probably a help. "Well, it was pretty obvious he believed it, if only because of how many times he almost got himself killed trying to get through to Hina. It wasn't until we did a Coupling with Skyknight and Firebrand that I really started to believe it myself, though."

He still remembered that glimpse into Aoba's memories. Brief though it had been, it had been vivid, and far too "real" for him to doubt any longer that his irreverent partner wasn't from the present world.

"Of course," he continued, "it wasn't that easy for everyone else. I think Doctor Conrad wrote it off as a hallucination caused by the unstable Coupling System the prototypes had. At least, until the Battle of Alaska happened." Dio shook his head, chuckling at the memory—one that he could finally find some humor in, now that he knew he hadn't made a colossal mistake that day. "Having a singularity open in the sky was kind of hard to ignore."

"I bet." Tsubasa shivered. "Just so you know? Those really aren't fun to actually go through, Weinberg-san. I didn't like reality taking a lunch break when Hina and Bizon first showed up with giant robots in the middle of Tokyo. It's worse when you know the math."

"Doctor Conrad's reaction a couple hours ago told me that much already, Miss Watase." Dio hesitated. "And call me Dio. If that crybaby does, his saner sister might as well, too. ...Just don't call me a siscon."

Tsubasa blinked, then slowly grinned. "Hey, anybody who realizes I'm the real smart one in the family gets to call me Tsubasa, Dio." She stuck out a hand. "I dunno what's going to happen next, but you can bet my brother is going to come up with another harebrained scheme soon. It's up to us to try and keep his head out of the clouds, right?"

Finding himself smiling back, Dio shook the offered hand. "If I know Aoba, we'll just be dragged along anyway—but at least we can watch out for the speed bumps, Tsubasa. He was bad enough at getting distracted in combat before; I can't imagine becoming a scientist has made him any better at focusing."

"It hasn't, believe me. He's better at being on time these days, but once something gets his attention—"

They were interrupted by a chime from the hangar's PA speakers. "Yo, Dio, Tsubasa," Aoba's voice called out. "Could you two both come to the lab? I had an idea."

Dio closed his eyes, counted to ten, and tried to prepare himself for a headache, before quickly crossing to the closest intercom panel. "Aoba. Do I even want to know what you have in mind this time?"

"Easier to show you, Dio. Let's just say Hina, Elvira, and I were looking over Tsubasa's Emphatier waveforms, and your latest results—ah, it's complicated. Just get to the lab, will ya?"

"Bring some painkiller," Elvira's voice cut in, sounding resigned. "Trust me, you'll need it when the tests are done."

Tsubasa's been tested with the Coupling System? And... my last recorded waveforms? Dio shot a glance at Tsubasa, but she only shrugged. Aoba... what are you up to this time?

"We'll be right there," he said cautiously. "Though I'm getting a very bad feeling about this." Shutting off the intercom before Aoba could reply, he looked back at Tsubasa. "Any idea what your brother and sister-in-law are up to now?"

"Beats me." Joining him as he headed back out of the hangar, Tsubasa frowned. "I mean, sure, they got a full readout on my Emphatier waveforms not too long before the jump, but I figured that was just for a control sample. No idea what Aoba's thinking of now." The look she gave him now was a wary one. "This is the guy who invented time travel, though. I think we're gonna need that painkiller."

Sighing, Dio could do naught but nod in agreement. Just be glad it's not Doctor Hahn, he told himself. Aoba's saner than that. Well... more ethical, anyway.

The day I think Aoba is "sane" will be the day I know I've lost my mind.

                                                                           -END-