Chapter Text
The Space Bridge's energy readings had teetered on the brink of losing control for seven full cycles.
This was not the first time [Optimus] had dealt with visitors from a parallel universe. He had read through the records from the mirror-verse incident three times, annotating every page. In theory, nothing should have gone wrong. But theory was theory, and theory put into practice always came up short. Scrap, which fool had sworn that Earth technology could sustain this junk-heap of a Space Bridge for an entire week?
The Lost Light's engineering crew had been stationed outside the transmission chamber for three days. The shift roster had been revised four times, and the coolant for the energy dampeners had already been swapped out twice. [Ratchet] had refused to leave the medbay since day four—not out of premonition, he said, but experience. After fighting a war for four million years, he maintained a near-paranoid vigilance toward any anomalous energy readings. Now he stood before the transmission chamber's control console, his optics fixed on the screen displaying the wildly fluctuating Higgs Field disturbance values. His welding torch spun once between his fingers.
"The disturbance peak just exceeded four thousand giga-electron-volts," he said. His voice wasn't loud, but in the enclosed space of the transmission chamber, every mech heard him clearly.
"What's the normal range?" [Rodimus] asked. He was leaning against the hatch frame, his posture seemingly casual, but the faint tremor in his shoulder plating gave him away—the captain of the Lost Light was tense.
"The normal range," [Ratchet] said dryly, "is zero. This thing shouldn't exist in the first place."
The glow on the transmission platform began to coalesce. It was an irregular, milky-white halo of light, its edges flickering with low-frequency violet, as if space itself were being torn by some external force. At the halo's center, the temperature skyrocketed from ambient to a plasma state in point-three seconds, then plummeted back below freezing in the next zero-point-three—the macroscopic manifestation of cross-dimensional quantum tunneling, a waveform recognizable to anyone who'd studied advanced particle physics. But recognizing it was one thing. Seeing it firsthand was another.
[Ratchet] had seen this waveform before. On the battlefield. Every time a Space Bridge was forcibly torn open, the residual energy traces looked exactly like this.
"Everyone, stand back," [Optimus] said. His voice wasn't loud, but it was deep enough to reach every corner of the chamber.
The halo began to contract, condensing from an amorphous dispersion into a sharply defined silhouette—tall, angular, silver armor encasing raw purple protoform. The shoulders were broad enough to bear the main support beam of an entire mine, the waist terrifyingly slender. The barrel of a fusion cannon emerged first from the light, followed by the purple insignia on the chest plate, across which a crack ran nearly the full width of the frame.
Every weapon in the room came up in the same instant.
Only one mech didn't move.
[Ratchet] narrowed his optics at the figure walking out of the Space Bridge. He had seen too many Megatrons—furious ones, wounded ones, ones barely clinging to life, ones wearing awkward smiles during peace speeches. But this Megatron was not like any he had encountered. He couldn't quite pinpoint what was different. Something about the armor, perhaps—an unvarnished roughness to it. Not battle damage, but something far older. Scratches from ore slag. Rust smears from the railings of the gladiatorial pits. A kind of primordial coarseness that four million years of war had never polished away. On his left arm ran a crude fusion-weld scar, clearly a battlefield self-repair—the method rough but effective, like the first patch a miner who'd walked straight out of the mines and onto the battlefield had ever given himself.
"Put your weapons down," Megatron said, sweeping his gaze across the room. His voice was low and steady, the barrel of his cannon remaining pointed at the floor. "I wouldn't mind a fight on your turf, but frankly, I'm not interested right now."
"You're not the shiny pacifist I know," [Ratchet] said. His welding torch was still in his hand. He hadn't lowered it. In any universe, facing any Megatron, lowering your weapon was not something a field medic should do. But he wasn't aiming it at the mech's helm either. He held the welding torch at an angle from which he could weld at any moment, and fire at any moment. That was the stance of a veteran, not a pacifist.
"You noticed."
"No scrap, I'm a medic." [Ratchet]'s fingers loosened on the torch's grip, then tightened again. "I could tell your lot's armor wear patterns apart with my optics closed. Who did those patch jobs on your arm? No one in your world gives you proper maintenance?"
Megatron looked down at the rough fusion-weld scar on his left arm. His optics flickered once—not the brightness of anger, but the brightness of being forced to remember. "Shockwave is a scientist. Not a welder."
"I hear that," [Ratchet] said dryly. "That tone of yours—you're showing off."
[Optimus] stepped forward. He did not raise his weapon. His faceplate was especially still in the afterglow of the portal, and he studied this unfamiliar arrival as though reading an open book—a book he thought he had already read the last page of, only to discover that this copy was bound in a completely different order. He saw the crack that nearly ran through the Decepticon insignia on Megatron's chest. Not fresh, but never repaired either. In his world, no Megatron would ever have allowed his insignia to remain damaged for more than a single cycle. Yet this one had not patched it. Not out of laziness. That crack was itself a statement: I come from a world where the war is not over. I do not need an intact insignia to prove who I am.
"You are not our Megatron," [Optimus] said.
"I never intended to be."
The two leaders faced each other across three paces. The energy readings on the transmission pod's display were jumping wildly; some alarm began to shriek; [Ratchet] turned away cursing to work the console. Someone shouted, "The dampener's about to overload!" Someone else was frantically cutting the auxiliary energy conduits. But [Optimus] did not look back. He watched this stranger, this mech who shared the same face, the same optics, the same gladiator-honed stance as the one he'd fought for four million years. Yet deep within those optics burned something he had not seen in his own universe's Megatron for a very long time. Not ambition. Not remorse. Something more primal.
"Welcome to our Cybertron," [Optimus] said.
Megatron stepped down from the transmission platform. The resonance frequency his pedals left behind was recorded by sensors installed beneath the chamber floor. [Ratchet] would later replay this data segment repeatedly—not because of any anomaly, but because the frequency matched, perfectly, the bedrock resonance frequency of the old mines beneath Iacon. A mech could change his faction. He could change his universe. He could not change which kind of ground his pedals remembered the feel of.
They sorted out several things very quickly.
First: the portal could hold for less than two days. After that, even if they wanted to send him back, there'd be no way. [Ratchet] delivered this with the tone of someone announcing an irreversible diagnosis. The primary dampener's Higgs Field induction coil had already developed micro-fractures. The auxiliary energy circuit had lost three nodes in the last power surge. The remaining coolant was no longer sufficient to support a second round of calibration. In other words, this portal was no longer a door. It was a fuse burning down to its end, and before it burned out, they had to send him back—or let him stay.
Second: this Megatron came from a world where the war was still going. Not a stalemate, not negotiations—a genuine, cannons-blazing war. The brightness of his optics was higher than that of most mechs in this universe, the kind of brightness that belonged only to someone who had never yet stepped out of combat mode, the kind that required constant battlefield scanning. Standing in the corridors of the Lost Light, his gaze swept involuntarily across every entrance and exit, every possible escape route, every weapon that could be hidden behind a maintenance panel. [Rodimus] noted that it took him only two minutes to walk from the transmission chamber to the briefing room, but in those two minutes, he had completed a full threat assessment of the entire ship.
Third: he demanded to see this universe's war records.
[Optimus] approved it. [Rodimus] couldn't understand. He caught up to [Optimus] in the corridor, lowering his voice; Megatron was already three corridors away, but the captain of the Lost Light never underestimated the sensitivity of any Megatron's audio receivers.
"Aren't you afraid that once he sees how we ended—"
"He will see it sooner or later," [Optimus] said, stopping in his tracks. His optics settled on the silver back of the figure examining an energy distribution panel at the end of the corridor. "Better we show him the full picture ourselves than let him find out from some other source."
"The full picture," [Rodimus] repeated. "You mean everything? Including—including—"
"Including the cost," [Optimus] said. "Let him see the cost."
[Rodimus] fell silent for a moment. He wanted to ask what exactly "the cost" referred to, but he felt there was no need. The Lost Light's database held a full four hundred petabytes of war records: casualty statistics, lost colony logs, atmospheric composition analysis reports after orbital bombardments, decommissioned soldier lists sorted alphabetically. Millions of years of continuous war records—others could no longer be sorted in any order, because [Rodimus] had seen [Ratchet] in the archives, spending an entire night welding storage interfaces for old-format fragments. The word "cost" contained too many things, and [Rodimus] knew very well that the cost [Optimus] was talking about meant everything one could look up in the public archives. Some things, even unspoken, could be extrapolated the moment you saw the numbers. And some numbers, once seen, could never be forgotten.
[Rodimus] was assigned as guide. He was more than willing. As captain of the Lost Light, he had encountered more bizarre parallel-universe visitors than the Council archives had on file—an Autobot traitor from a mirror universe, future Cybertronian refugees from a time rift, even another version of himself from some parallel universe whose designation he himself could no longer recall. But a Megatron still fighting a war? That definitely made the top three.
"Don't you find it strange?" [Rodimus] said as they walked. "A Megatron who's not looking to cause us trouble—I mean, not looking to topple the peace we painstakingly built—and instead wants to hit the archives first?"
Megatron gave no answer to that question. His stride was longer than any Megatron [Rodimus] was used to, every step like a forced march, the gait of a miner hauling ore toward the lift in an underground tunnel—slow, coiled with power, each pedal planted fully before the next step was taken.
They started from the ruins of what had once been Iacon.
There were few places not rebuilt after the war. Iacon's northern district had taken an orbital strike late in the war, blasted into one enormous crater. The Reconstruction Committee had spent a year debating what it should become; someone proposed a war monument, someone else proposed filling it in to build a new industrial zone, and in the end, [Starscream] said just leave it—let every Autobot who makes the long pilgrimage here see exactly what they won. This had nearly triggered a fistfight in the Council chamber, but the vote passed in the end. Was it because the idea was right? No. It was because no one could agree on any alternative, and the ruins themselves had been objectively present the entire time.
The ruins had now become a heritage site. The wreckage of the dome still held the shape it was in when the orbital cannon struck it; molten alloy hung suspended in midair, held by the gravity field in a counter-intuitive equilibrium, like magma frozen halfway through a drip. Every time [Rodimus] came here, he felt those alloys were still dripping down from the sky, but they'd been dripping for three million years.
Megatron stood at the edge of the ruins, looking at the skeletal dome. There was no expression on his faceplate, but he looked for a long time.
"What is this place?"
"Iacon Library site," [Rodimus] said, standing beside him, his optics sweeping over the molten alloys suspended overhead. "Took an orbital strike about two million years into the war. The mechs inside never made it out. They never rebuilt it. The Council said leave it as a memorial."
Megatron didn't answer. He stared at that ruin for so long that [Rodimus] began to feel uneasy. His knuckles slowly tightened at his side, something deeper shifting—as if he were calculating the coordinates this ruin would correspond to on his own war's trajectory.
They kept walking. Past the Council plaza, where [Rodimus] explained that brawls broke out regularly in the Council now, because the Autobot and Decepticon seats were split evenly and every single proposal took at least three cycles of arguing. Yesterday's fight, for instance, had been about whether the lights on the Energon Tower's peak should be blue or red—blue for neutrality, red for remembrance. In the end they decided on blue for the upper half and red for the lower. No one was satisfied, but no one had the energy left to keep opposing it.
As they passed the energy distribution station, [Rodimus] said the place was now governed by a new energy code [Shockwave] had signed, a document so intricate it seemed designed to torment. Which drop of energon went to which district, which block to which time slot, which time slot reserved for which purpose—all of it written into the code, the calculation formulas in the appendices alone as long as a doctoral dissertation. [Shockwave] now managed energy distribution, and he managed it with the same airtight precision he had once applied to weapons R&D. [Rodimus] didn't know whether a former war criminal spending four million years killing countless people and then suddenly writing formulas for your electric bill was a good thing or a bad thing. All he knew was that this month's industrial zone allocation file was fifteen percent thicker than last month's.
Then they passed the newly constructed Memorial Park, where [Rodimus] said the memorial wall bore the names of all confirmed fallen soldiers—both sides, alphabetically, no faction distinctions. Someone had carved new names into the wall—not late additions of the fallen, but the serial number of a civilian maintenance worker. Rumor had it he'd discovered that using an encoder at a certain angle burned grooves of a different width, and if the names he etched weren't recorded by the memorial registry, then they were people he simply wanted to add.
Megatron stopped in front of that wall.
"Four million years," he said. Not a question. He simply turned the number over in his vocalizer, as if tasting it. His optics swept across the countless names on the wall, the etched grooves that covered the entire surface with a uniform density, top to bottom, left to right—a death-chart of stars, alphabetically indexed. Every name corresponded, in his own memory banks, to a date, a set of coordinates, a tactical designation. He refused to cross-reference them at this moment, but his processor was already doing it.
"How long has your world been fighting?" [Rodimus] asked.
"Shorter than yours," Megatron answered. "And it's not finished."
He pulled his gaze from the wall, sweeping it over the Autobot insignia on [Rodimus]'s chest, over the Cybertronians crossing the plaza who wore no faction insignia at all, toward the distant Council building—once the site of the Senate. Every detail was being recorded by his optics, but he offered no commentary. He was only watching, like someone reading a history not yet filed into any archive.
"The Decepticons here," he said. "They all followed the other me and surrendered?"
"Not all of them." [Rodimus] considered. "[Soundwave]'s still around. [Starscream]'s still around—oh, and [Starscream]'s a Council member now, you can imagine the circus. And there are small scattered groups, not much of a force." He paused; the brightness of his optics flickered with an almost imperceptible fluctuation—the usual precursor for when the captain of the Lost Light was about to ask a question he might not like the answer to. "Do you want to see him?"
"I'll pass on Starscream. Same in every universe."
"I meant the other you."
Megatron didn't answer right away. His fusion cannon's indicator light flickered once, at a frequency that reminded [Rodimus] of a detection radar—scanning, locking, standing by. In that exact moment, the streetlamp just happened to shift from dull red to orange-yellow, splitting his faceplate exactly in half—one half caught in the light, the other still cold silver. For a single instant, [Rodimus] felt the mech standing beside him was not a mech, but a commander that had just completed all intelligence gathering and was internally debating its next move.
"Lead the way," he said.
The streetlamp returned to normal. His faceplate became whole, silver, once more. When [Rodimus] heard that answer, he paused briefly. The truth was, the answer he least wanted to hear was exactly those two words: Lead the way.
Megatron was coming to meet himself. Two Megatrons. The same faceplate. The identical voice. Similar life trajectories, from the bottom of the mines all the way to the door of the Galactic Council, now standing at entirely different coordinates staring at the same question: at precisely which step had they diverged and arrived at today? One was still fighting. The other had surrendered. One wore the purple Decepticon insignia, a crack in it that had been left there for Primus knew how long. The other had switched to a red Autobot badge and had written in his memoirs that "tyranny cannot earn peace."
And [Rodimus] found that he was not looking forward to this meeting at all, yet felt that no one but himself should be standing in the front row to witness it happen.
The meeting place was chosen in [Optimus]'s office. Not an interrogation room, not a cell, not any room with surveillance equipment and one-way glass—just a normal office, with windows, a desk, and two cups of high-grade energon on the corner of the desk, untouched. The artificial rain outside had just stopped, and Iacon's lights blurred into a wash of warm orange-yellow across the wet window glass.
[Optimus] had pushed the desk to one side, dismissed all guards, and left only himself and [Ratchet] present. [Ratchet] stood in the corner with his arms folded, his welding torch hanging from his waist at its most convenient angle, his optics sweeping the room, wearing an expression that said anyone who starts a fight in here is getting welded to the wall. But he knew, deep down, that he wouldn't be the one to throw the first punch. Because he'd seen that fusion-weld scar. A mech who repaired his own armor wouldn't fire the first shot in someone else's office.
By the time [Megatron] entered, the electromagnetic cuffs had already been removed from his wrists. [Optimus] had insisted on this. During the preparation, [Ratchet] had objected vehemently, saying removing the cuffs was equivalent to putting a former war criminal and a freshly arrived interdimensional war criminal in the same room and betting on whose fusion cannon would charge faster. [Optimus]'s answer: if two Megatrons were going to meet and one of them was wearing restraints, the meeting would have reached its conclusion before it even began. He had no intention of predetermining a winner or a loser for this encounter.
[Megatron] wore simplified civilian armor—no fusion cannon, no battle treads. He looked like a veteran who'd been retired for a very long time, the kind who, after mustering out, chose to work the night shift in the archives. His armor had no new scratches but hadn't been waxed either; his joint hydraulics hissed so faintly they were only audible in a completely silent corridor. His optics were very dim, which was normal in this universe: after the war ended, most mechs' optics had gone dark, as if their systems had automatically entered power-saving mode. But to the other Megatron's optics, it registered as signal decay—not just physical deterioration of optical sensors, but a spark that, after making too many decisions it wasn't sure were right but was absolutely certain were irreversible, had dimmed from a blaze to a constant low burn.
Megatron watched his other self walk in. His optics swept from helm to pedal and paused on the Autobot insignia for two full seconds before moving on. That insignia was fastened perfectly straight. Head-on, the upper-left region of the chest plate, the primer, the edge finishing—all of it was standardized to a degree that suggested someone had spent time studying the badge-wearing protocol. But Megatron noticed an extremely small dent on the back of the badge, the kind left by repeated removal. This mech had taken the badge off many times—for interrogation, perhaps, or for cleaning, or possibly to sit alone on his recharge berth, staring at it through the entire night, and then pin it back on the next day.
"Sit," [Optimus] said, gesturing to the two chairs in the center of the room. They were placed facing each other, an empty table between them. The tabletop was so clean it reflected the light. Above it hung a single low-wattage overhead lamp, rationed out of the postwar energy quota—not bright, but just enough so that every faceplate had half of itself in shadow.
Both Megatrons moved toward the chairs at the same moment. They stepped forward with the left pedal simultaneously, the stride length identical—muscle memory formed by long-term maneuvering in confined spaces, a habit the same kind of life had carved into their gears over hundreds of thousands of years. [Ratchet] cursed under his breath at the sight of it. He'd seen too many coincidences in his lifetime. Some could be explained. Others only made you want to run the sensor diagnostics all over again.
They sat, facing one another.
The silence stretched nearly thirty seconds. Thirty seconds long enough for [Ratchet] to double-check everyone's vital signs, long enough for the overhead lamp to flicker a second time, long enough for Megatron to complete an analysis of every microscopic wear mark on the opposing facial armor and reach a conclusion that deepened his optics by a fraction, though no one detected it.