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The war ended not with a victorious bang, but with a whimper.
The spark of Primus, their planet’s core, went out millions of years ago as collateral from the ravages of their conflict, and with him, their homeworld became uninhabitable. Both sides of course blamed each other, and the neutrals blamed them both — though special scorn went to the Autobots when Optimus Prime cast the AllSpark out into deep space, thus rendering them all infertile and incapable of conceiving new life, let alone constructing mechs cold. Their numbers dwindled through a mixture of battle, disease, and famine, until finally Megatron was faced with a simple choice:
Sign a ceasefire to save their people, or allow their species to go extinct.
With an uneasy peace at hand, both sides retreated to the Ark and the Nemesis to tend to their wounds and grieve their dead while their leaders jointly ventured to Earth to retrieve the AllSpark, much to their respective soldiers’ chagrin. To the Autobots, their noble leader was going alone with a savage, brutish, basal Alpha who could do untold atrocities to him. To the Decepticons, their savior was at the mercy of a pious, polished, elite Omega Prime whose saccharine schtick was surely a cover to get close enough to sink his blade into their leader’s spark.
To the mechs in question, they were on a mission with their ex-bondmate.
The concept of conjunx endura was supposed to last forever, until one or the other of the conjunxed pair returned to the AllSpark. However, there was also conjunx disjunta, in which each of the rites were symbolically undone. Unlike conjunx ritus, a sparkbond was irreversible. Permanent. Able to be broken only by death…
…or, apparently, the Matrix of Leadership enveloping one’s spark.
Megatron used to think that his bondmate truly had died, that the Senate had pinned Orion Pax down and pried open his chest plates and extinguished his spark with the Matrix, so horrible was the pain that ripped through his chassis, through his very spark, a horrible scream building within his throat as he fell to his knees all the way in Kaon. He used to believe that they killed his Orion and replaced him with that thing called Optimus, who walked around in the reformatted, “upgraded” frame of Megatron’s dead lover, the gravest and most personal of insults.
As millennia passed, he realized that the truth was much worse: that Orion’s spark still burned within that alien chassis, behind those sad ethereal sapphire optics, coloring the timber of that deep baritone voice that pleaded with him so sweetly to stop his conquest of destruction. That it was the Matrix, the will of Primus himself that severed their bond.
That Orion did it willingly.
This renewed millions of years more of dark, bitter hatred fueled by betrayal, but try as he might, Optimus would not die, nor would Optimus give up on him, constantly asking him to please stop and work with him instead of against him to save their people.
Megatron did not listen for the longest time. But eventually the energon staining his servos grew too heavy, his numbers grew too few, and the optics of his remaining soldiers too hollow and desperate.
And so, striding out onto the would-be battlefield towards a life-weary Optimus, Megatron held out not a sword, but a servo.
They spent years scouring Earth for the AllSpark together, taking on human ‘big rig’ semi trucks as their alt-modes so that they could drive across the continents without revealing themselves to the planet’s indigenous lifeforms, following clues found only in myths and ancient art.
At first, their partnership was distant and frigid. They rarely spoke, even when it seemed a necessity, and when they recharged they often did so out of sight of each other. But as their years of self-imposed exile turned into decades, their relationship began to thaw. Slowly, Optimus began to make quiet comments about how beautiful the planet was and how curious its lifeforms were, almost to himself. Megatron even began to agree, so reverent was the tone of Optimus’s voice, as deep and rich as the planet’s immense blue oceans and warm as its deserts. His voice was like music when it wasn’t bellowing war cries, and Megatron found that he missed it.
But Megatron could never make things easy.
“I find it… interesting, your fondness for this world,” he said one day as they drove slowly along a precarious mountain path.
Optimus did not deem it worth restraining the offense in his field. “Oh?” he gruffed, already gearing up for an argument, and while he may be an Omega, Megatron knew from firsthand experience that he could give as good as he got. The Functionist painting of Omegas as obedient ornaments for the upper castes or pathetic baubles for the lower castes was as full of slag as the rest of the drivel that came out of their fool mouths.
“After all that we have seen watching and searching this miserable rock… I can understand finding such alien wilderness beautiful, but the humans? What of the war, Optimus, the hatred, the death? I’ve seen little more than cruelty in the time we’ve been here.”
“If they had watched and observed our species and homeworld for the past millions of years, would they say the same? Have we no worth beyond the pain we’ve inflicted, have we no potential? And throughout the war, did we not love? I know I did.”
Megatron wished his field prickled with jealousy, but instead it was awash with grief before he clamped it down. “You… found love, then?” he said mildly and absolutely not at all timidly.
“...I found all sorts of love,” Optimus replied after a moment. Then his tone turned dark and heavy. “And I lost many of those I loved to this war.”
To you went unsaid.
“It was you who taught me early on not to get attached,” Megatron muttered.
Optimus’s engine revved as they started up a steep incline, the dirt road churning beneath their tires. “You mean to tell me you did not spend your ruts with anyone in all this time?”
“Oh, please. Rutting alone would have compromised me for too long. Of course I took a partner.”
“A partner? Not a rotating harem of disposable berth warmers?”
Megatron angrily revved his own engine and snapped, “Who do you think I am? A Senator?”
“Who was the partner, then?”
“Jealous, Prime?”
“I need a name before I make my point.”
“That’s awfully petty of you.”
“Shall I guess?”
“I’d be greatly amused if you did.”
“Soundwave.”
Megatron’s engine quieted down into a rumble. “...Of course it was Soundwave.”
“No one else?”
“As if I’d let anyone else see that side of me.”
“Then can you truly claim not to be attached to Soundwave if you’ve rutted with him alone for millions of years?”
“A mere side effect of Alpha coding, and he is my sole exception. And who, may I ask, did you share your heats with?”
“Ratchet, Elita-1, Ultra Magnus, Jazz, Ironhide…”
Megatron huffed.
“Now who’s jealous?”
“I didn’t know you could be so vulnerable with so many.”
“Vulnerability is what gives life meaning,” Optimus argued. “For all those I have loved and lost, if I could go back and give myself one warning at the beginning of the war, it would be to love with less restraint. I cannot imagine spending one’s life in fear of love for the consequence of pain. Without love, what else is there to live for, to fight for?”
“What a remarkably selfish approach to life. Love is not some all-powerful force that makes the universe expand and the galaxies spin, and it has no place in politics. In fact, I argue that love is a corrupting force, a plaque that obscures clarity and encourages inequality. For example: a mech will love their conjunx and sparklings over a stranger. When asked who should have the last rations of energon, will they choose their pack, or the strangers? Love makes mechs choose their own kind over the collective. I am above such weakness, as any Lord High Protector should be.”
“Why fight for the collective if not out of love?”
“Respect. Objective ethics. Because it’s the right thing to do.”
“Are the Autobots counted among your respected collective? Are the neutrals?”
They drove in silence for a long while, before eventually Megatron asked, “Why do you think I offered a peace treaty, Optimus?”
Optimus carefully rounded a curve with no guardrail separating them from the sheer drop to the sharp rocks below. “Part of me is expecting to be shot in the back as soon as we find the AllSpark.”
“I wouldn’t put it past me,” Megatron said tiredly. “But that would just reignite the war, and your Autobots would fight to the last spark in your name. They would plunge our species into extinction and leave our legacy one of death and destruction, a foolish people that unmade themselves, and they would do it out of love for you.”
Optimus was silent.
“...Optimus,” Megatron prompted quietly.
They reached the peak of the mountain, and Optimus transformed back into root mode, sitting down on the edge of the road to look out over the sprawling valley below, awash with pale mist. An eagle cried somewhere nearby.
Megatron transformed and sat beside him, glancing at him in concern.
Optimus just smiled behind his mask, a pained, bitter thing. “I guess it was selfish of me to hope that you stopped because somewhere, deep inside your spark, you still loved me.”
Megatron’s expression pinched with pain, and he looked away, gritting his denta as his fingers dug grooves into the earth. “Of course I still love you,” he spat. “I’ve never stopped loving you. It’s why I hated you, wanted to destroy you and purge you from my life, to scrub my plating until it grew brittle and shattered just to remove the sensation of your touch. But that love wasn’t enough, Optimus, for either of us. We made it clear to each other that we would sacrifice the other for Cybertron and our people every time. Talk as you will about love, but your applied philosophy is that your moral code was worth more than the bond of our sparks.”
“I never bonded again,” Optimus said suddenly. “Not in all this time. No matter how many times I was asked. I never bonded again. Because the Matrix may have severed our bond and undid your Mark, but it did not sever my will. Yes, I will always put our planet and our people before you, just as you will always do the same to me, but my spark still belongs to you, and always will. But for your own sake, I hope you find love again. That you allow it. Even if you want nothing to do with me anymore.”
The wind howled around them and buffeted their plating as they sat in silence.
“...My rut is due in three years,” Megatron murmured. “If we do not find the AllSpark by then…”
Optimus just tilted his helm, his finials twitching minutely in a way that made Megatron’s energon boil.
“...will you spend it with me?”
Optimus’s sapphire optics widened and searched his face for any evidence of a cruel trick, but there was none. “Why not Soundwave?” he blurted.
Megatron huffed. “If you want me to leave Earth and return to the Nemesis, you need only say so. This joint search was mostly symbolic anywa-”
“Yes,” Optimus stuttered, opening his mask. “I mean- No, don’t go. Yes, stay. Yes, I’ll spend it with you.” He facepalmed.
With Optimus’s gaze consumed by his palm, Megatron didn’t hide his soft smile and instead focused his energy on not getting his hopes up.
–
Time passed easier after that. They recharged next to each other, chatted about simple nothings over energon, and Megatron even helped Optimus save a cat from a tree.
It was nice.
–
They did not find the AllSpark in time, though they were close.
It was the dead of night and the two of them were following an abnormal energy signal that led them into a deep cave when Megatron froze, his vents hitching.
Optimus immediately turned around and shined his headlights on the larger mech. “Are you alright?”
His cooling fans clicked on then, and with a groan, Megatron braced himself against the wall. “I’m fine.”
Smelling the nanites that said fans blew in his direction, Optimus’s finials sprang upright and he barked, “You are not fine you are in rut! How long have you been hiding the symptoms?”
“Since midday.”
“Why?”
Megatron groaned and closed his optics, mashing his faceplate against the cave wall. “I… am in control… I would never impose…”
“Megatron, did you forget our arrangement?”
“It was a pleasant hypothetical, not a promise.”
“I took it as a promise.”
“All the more r-reason-” Megatron’s engine dipped into a low growl, and the musk of a large Alpha warframe in rut was bringing up both Optimus’s battle and interface protocols. Optimus began to walk closer, and Megatron snarled, “Stop.”
“When was the last time you spent a rut alone?”
Megatron groaned again and vented heavily, his servos balled into fists. “The mines.”
“Megatron,” Optimus scolded.
“Optimus, you need to leave me.”
“That’s not happening.”
“If you d-do not leave me, I-I…”
“What happened to you being in control?” Optimus taunted, and Megatron snarled as he sank to his knees, fingers leaving gouges in the cave wall.
“I am,” Megatron managed. “But your presence… hurts…”
“Megatron, a solo rut at your age can permanently damage internal components.”
“I know that! Aghhh…”
“So why are you doing this? To prove a point? If you didn’t want me, you could have called for extraction from the Nemesis.”
“I do want you,” Megatron said forcefully, risking a glance at the other warframe and immediately regretting it at the sight of those slender, grabbable hips. “I want you s-so much it’s killing me. But Optimus, y-you…”
“What? What about me?” Optimus snapped. “You don’t want me to find the AllSpark alone, is that it? You think I’ll betray you?”
“I don’t want to hurt you,” Megatron whispered, rubbing his helm against the cool cave wall in a desperate attempt to cool his overheated plating.
Optimus closed the rest of the distance and knelt down in front of his oldest enemy and ex-bondmate, cupping the back of Megatron’s helm to press it to his, turning off his headlights to plunge them into darkness interrupted only by the moonlight filtering in through the cave entrance and their biolights. “Maybe I want to be hurt,” he murmured.
With a broken noise, Megatron surged forward and captured him in a searing kiss, pushing him down onto the cave floor.
Optimus dismissed his battle protocols and decidedly indulged his array as he spread his legs and welcomed Megatron between them, letting the larger mech grind their panels together as he ravaged his intake and feverishly ran his servos all over Optimus’s frame, caressing and groping and tracing seams.
Eventually, Megatron broke their kiss and tucked his face into the curve of Optimus’s neck cables, in-venting air deeply and shivering despite the heat pouring off his frame, his frantic grinding slowing to a gentle, languid rocking. “Open,” he rasped, dragging his glossa along Optimus’s main fuel line and feeling the pulse of his fuel pump, and Optimus made a choked-off noise as he instinctively bared more of his throat in submission and opened his valve panel. At the sound of his panel snapping open, Megatron gently sank his fangs into Optimus’s cables and opened his spike panel, freeing his pressurized and weeping spike, but rather than immediately mount him, Megatron slid down his frame, mouthing and pressing heated kisses to every sensitive seam and sensor before settling between his silver thighs and licking into his valve like a starving mech.
“Frag,” Optimus panted, rolling his hips into that steaming mouth as Megatron hooked his legs over his shoulder pauldrons, allowing Optimus to control the pace and the pressure with simple flexes as his dark servos massaged and held onto Optimus’s hips for dear life. “Just like that… slower, deeper… Oh, Alpha…”
Megatron let out a deep, rumbling growl into his valve that vibrated the internal sensors, then slid upward to suckle his anterior node into his intake at the same time he freed a servo to slide two fingers into the hot, wet folds of Optimus’s mesh, pumping them languidly and crooking them over the sensors as he bobbed his head minutely on the swollen node, sucking and swallowing around it with audible sounds as Optimus’s lubricant glittered on his chinguard.
The sight was absolutely obscene.
“Megatron!” Optimus shouted as he overloaded, chassis heaving as the warlord milked out the aftershocks, continuing to massage his inner walls and swirl his glossa around the head of his node.
Not stopping to vent, Megatron immediately crawled back up Optimus’s frame and kissed him deeply, coating his glossa with the taste of his own lubricant while his spike rested heavily atop his abdomen.
Even with this larger frame, Optimus knew that it would go deep.
> Heat runtimes initializing . . .
Optimus’s optics widened and he keened into Megatron’s mouth, servos not knowing whether to clutch the mech closer or push him away. Managing to turn his helm away from the kiss enough to speak, which just set Megatron to licking along his finials, Optimus shakily breathed, “You t-triggered my heat…”
Megatron froze for a moment, spike bobbing tantalizingly close to Optimus’s clenching valve, calipers squeezing down on nothing. “D’ya wanna stop?” he rasped, hoarse, his entire frame quaking with the effort to hold back.
“Primus, no,” Optimus panted, finding his servos and cradling Megatron’s helm in his palms. “...Do you?”
Rather than answer, Megatron just pulled back and forcibly flipped Optimus onto his front. Sensing his intent, Optimus got his knees underneath him and presented for the other mech (my Protector, my Alpha, his heat coding supplied), arching his back as he mashed his cheekplate into the cave floor.
With a snarl as his own rut coding took in the display and reverently supplied my Omega, my Prime, Megatron grabbed his spike and coated it in the leftover lubricant on his servo before lining up the head and popping it inside Optimus’s eager valve. The mech below him let out a breathy cry and immediately thrust himself backwards at the same time Megatron thrust forwards, and their combined efforts sank his spike home in one sharp movement, his pelvic span hitting Optimus’s aft with a clang as his servos curled around his hips in a vice grip.
Optimus clawed at the ground and whimpered, trying to move, but Megatron’s servos held him still and fast to his pelvis, the larger mech savoring the feeling of suddenly being inside Optimus’s tight wet heat, calipers cycling rhythmically around his spike as he twitched and whined.
Bending himself over the smaller mech’s back, Megatron shifted his arms until they were wrapped around Optimus’s middle and then bit down onto his shoulder plating with his fangs, carefully avoiding the nape of his neck, and began thrusting, slow and deep, the head of his spike teasing at Optimus’s gestation tank seal. Releasing his bite to lick the dents, Megatron purred his engines to vibrate his spike and Optimus went strutless, his optics rolling back as drool pooled in his intake.
“Alpha,” he eventually whined, spreading his legs wider and purposefully rippling his valve, “please…”
“You want more, Prime?” Megatron growled, servos roaming around the front of Optimus’s chassis and kneading at his windshields, making him shudder. The Alpha deeply in-vented at Optimus’s neck again. “So do I.”
And with that, a servo slid up to wrap around Optimus’s throat and lifted him up off of his chest and servos, the other dark servo grabbing his hips to steady them as he pulled all the way out and then slammed back in, bouncing Optimus with the force of each powerful thrust.
Optimus clutched at the servo around his throat and did his best to move to meet each thrust, throwing himself down to impale himself on the Alpha’s spike, filling the cave with the most obscene wet noises as each impact of hips against his aft and spikehead against his seal punched out desperate wanton noises from his vocal emitter, drool running down from the corner of his intake.
The next thing he knew, he was being pulled even further back until he was leaning against Megatron’s chest and sitting in his lap, his face being turned by the servo around the base of his jaw, and Optimus shuttered his optics in preparation for a kiss only for them to snap back open when Megatron licked the oral lubricant from his cheek and chin and began pressing soft kisses around his optic and temple. Squirming, wanting the Alpha to move again, Optimus let out a frustrated growl and caught Megatron’s lips with his, biting and sucking on them as he ground himself in circles on the still spike, cycling his calipers again.
Megatron let out a throaty chuckle and let go of Optimus’s throat, opting instead to grab him by the plating at the nape of his neck to shove him back down onto his knees, his face mashed into the floor as Megatron pulled all the way out with a wet squelch.
Aching and empty and pinned, Optimus whined pitifully and wiggled his hips only to be bit on the aft, and when he yelped and snarled in response, he was cut off by being speared open on the spike he missed so much, held still, and then deprived of it once more only for it to slam home again with a lewd noise.
Then Megatron picked up the pace, hauling him back onto his spike with each aggressive thrust, growing faster and faster until lubricant was splashing all over both of their thighs and the floor and his spike was kissing his seal insistently and suddenly Optimus was overloading again with a scream and a fountain of lubricant that squirted out of his valve.
“Fragging- Primus,” Megatron said brokenly, feeling the Omega’s gestation tank open, forcing himself to keep up the brutal pace and pulling Optimus’s helm back by the crest as his glossa lolled out, sapphire optics so bright they looked at risk of burning out as Megatron took his pleasure, knot rapidly swelling until finally with a last few forceful thrusts and a bellowing cry that shook the walls as his knot inflated and locked them together, transfluid surging through his spike to begin coating the walls of that waiting chamber.
They rode through the aftershocks together for a long klik, and then Megatron nearly collapsed on top of Optimus, barely catching himself before easing the both of them onto their sides, rubbing one servo soothingly over Optimus’s overheated frame while the other held up his leg to take pressure off the hip joint, nuzzling into his neck, lovingly licking and kissing at the cables there.
It took a long time for Optimus’s processor to reboot, and when it did, allowing him a filter of clarity, his finials snapped back as he blushed, a servo slipping to his abdominal plating, feeling the faint tremors as transfluid flooded his tank, bowing the plating outwards ever so slightly.
Megatron tensed behind him, his open electromagnetic field rapidly shrinking. “It won’t take,” he rasped, his grasp spasming tighter around the Omega in his arms. “Not unless we bond.”
“And what if we do?” Optimus blurted.
“...What?”
“What if we bond again? What if we end the war with the revival of our world and a litter of sparklings?”
Megatron frowned and hid his face in the nape of Optimus’s neck. “That’s the heat talking.”
“...So you don’t want to,” Optimus said, his voice thick and brittle.
“Of course I want to, it’s all I’ve ever thought about for the past four million years!”
“What do you think I’ve been thinking about for the past four million years?!”
“I don’t know, how much you hate me? How Primus Himself dissolved our union?!”
“It speaks to me, you know.”
“Prime,” Megatron said tiredly, “what are you on about?”
“The Matrix. It… does things on its own. Sends me… impressions. Compulsions. I think… I think it triggered my heat. I think it wants us to-”
“Optimus, don’t do this to me,” Megatron said brokenly, burying his face further into his neck. “Please don’t do this to me. You’re not cruel, not like this.”
“After all that you’ve destroyed in the name of war, Megatron, don’t you want to create in the name of peace? Together?”
“I don’t deserve it.”
“Then what do you deserve?”
“I forfeited my right to a family long ago. The best I can hope for now is to protect Cybertron and our people to the best of my ability.”
“And what of me?”
“You deserve better than I. Primus broke our bond for a reason, Optimus. We weren’t meant to be. You should move on, find someone else to carry for.”
“There is no one else.”
Megatron actually smiled and shook his helm. “You always were impossibly stubborn…”
Optimus smiled back and nestled back against his chest, twining their fingers together where they rested over his spark.
“...Here you are actually asking for something for yourself, willing to defy Primus and all your Autobots, and I’m actually arguing for you to- what?”
“Self-sacrifice in the name of decorum, it seems.”
“I should be struck down where I lay for doing such a thing.”
“Yes, you should.”
The two of them actually chuckled, and Megatron shifted his free servo to Optimus’s abdomen.
“I will not bond with you, not yet,” he said softly. “But… I do offer this as my Act of Intimacy.”
Optimus lifted Megatron’s servo to his lips and kissed his knuckles, feeling his optics sting again.
“I think I can accept that.”