Chapter Text
Brainstorm was going to scream. He was going to throw a full-scale tantrum. And maybe even topple the bench just to prove his point. Because this—this fragging nonsense—was beneath him.
A stabilizer kit for public transit mechs. That was what the requisitions board had dumped on his lap. Not a quantum singularity cannon. Not a time-folding bracelet. Not even a halfway interesting thermal regulator. No, he was supposed to waste his genius making sure commuter frames didn’t wobble when they hit a pothole.
He jabbed a soldering tool into the circuit board with unnecessary force, muttering loud enough for the walls to hear. “Do you know what I could be doing right now? I could be designing engines that run on nothing but smug satisfaction. I could be unraveling the mysteries of cross-dimensional physics. I could be solving the big problems, not this pitiful scrap!”
His wings spread wide, an involuntary punctuation to his outrage. He glanced around his lab—half a junkyard, half a shrine to invention—and felt the insult all over again.
The state didn’t deserve him. Cybertron didn’t deserve him. None of them had the vision. None of them could see the brilliance simmering just beneath his plating, waiting for the right project, the right excuse to change everything.
Instead, he got stabilizers.
He slumped dramatically into his chair, one servo pressed to his forehead like he was a tragic figure out of a bad drama. “Brainstorm,” he whispered to himself in his most woeful tone, “you could have been a legend.”
The chair squeaked under him, unimpressed.
His comm pinged.
Brainstorm didn’t even look at first. Whoever it was could wait. He was busy languishing. But then the ping repeated, sharper, carrying the encrypted tag that meant official channels.
He groaned, dragging himself upright. “If this is about another fragging stabilizer—”
It wasn’t.
The message header blinked Nightbeat in bright, no-nonsense glyphs. The text was short:
> Forensics lab. Now. Got a new mission.
Brainstorm froze. His wings perked, then twitched back down. “Mission?” he muttered. “I don’t do missions. I invent. I innovate. I… oh, frag me sideways.”
Because he knew exactly what that meant. If Nightbeat was calling, it wasn’t some routine errand. It was serious. And the last time he’d been dragged into something “serious,” he’d ended up blowing out half the processing wing of the city archives.
He pinged back a reply with as much sulk as could be compressed into a single datapacket.
> This better be important.
The return came instantly.
> It is. Move your aft.
Brainstorm threw down his soldering tool so hard it bounced off the bench. “Slag it! Fine! But only because if I ignore him he’ll send someone to drag me by the wings.”
He stomped toward the door, muttering all the way, leaving the stabilizer kit abandoned in disgrace.
The walk through the corridors did little to cool him down. If anything, every civilian mech he passed gave him another excuse to huff and puff about how wasted his talents were. They didn’t even glance up at him. They didn’t know who they were walking past. A genius! A revolutionary! A mind that could redefine the entire fragging galaxy!
And yet here he was, trudging toward the forensics lab like a scolded sparkling.
By the time he reached the door, he’d worked himself into another full-blown monologue, muttering about bureaucrats and bean-counters and how one day he’d show them all.
The lab doors slid open with a hiss, cutting him off mid-sentence. The air inside smelled faintly of disinfectant and overcooked energon. Rows of equipment lined the walls, all neat and tidy—everything Brainstorm’s lab decidedly was not.
And in the middle of it, leaning over a console like he was married to it, was Nightbeat.
Brainstorm sighed loudly, wings flicking for maximum dramatics. “All right, detective, what’s so important that you had to drag the greatest inventor on Cybertron out of his lab? This had better be good.”
Nightbeat didn’t bother looking up. He just waved a hand toward the far side of the room. “Come take a look at this.”
Brainstorm dragged his pedes, muttering. “If this is another boring calibration problem, I swear, I’ll—”
He stopped dead when he saw the slab.
A body lay there, stiff and still, armor caved in around the spark chamber. But it wasn’t the wounds that froze Brainstorm. It was the wrongness of it. The way the lines of the frame seemed warped, as if something inside had chewed outward instead of in.
Brainstorm’s wings went stiff. “Eugh.”
Nightbeat finally straightened, visor gleaming like it was part of the act. “We’ve got a problem. Civilians turning up dead. Spark cavities hollowed. Witnesses say they saw a shadow that didn’t move like a bot should.”
Brainstorm’s optics narrowed. “This isn’t a science problem, this is a horror story. You need a priest. Or—” he flailed his hands, “—someone who handles this kind of slag. Not me.”
Nightbeat smirked faintly. “Priests don’t build detection equipment.”
Brainstorm gagged theatrically, pressing the back of his hand to where his mouth was under his mask. “You seriously want me to poke that thing? Oh, no. No, no, no, no, no. This is outside of warranty, pal.”
“Too late.” Nightbeat gestured at him like a judge delivering a sentence. “You’re already in.”
Brainstorm groaned loud enough for the civilians outside to hear. “This is abuse of genius-level talent. Criminal, really.”
And then—like fate intervened to keep him from storming out—he saw him.
Across the room, red paint gleaming under the harsh lab lights, stood a mech so clean-cut he made precision itself look sloppy. Broad shoulders, perfect plating, visible microscope alt-mode, the definition of Brainstorm’s type leaned over a console. His fingers moved with careful efficiency across a datapad.
Brainstorm forgot his protest mid-breath.
“Who’s that?” he blurted, wings flicking upright.
Nightbeat didn’t even glance over. “Perceptor. Forensics analyst. He’s been helping me cross-reference patterns in the killings.”
Brainstorm’s vents hitched. “Perceptor, huh? Never heard of him. But wow, look at him. Look at the way he types. That’s… that’s art.”
Nightbeat raised a brow ridge. “Are you seriously ogling my forensics partner while there’s a corpse on the table?”
“Yes,” Brainstorm said without hesitation. “Absolutely. That is exactly what I’m doing. And frankly, it’s the only reason I haven’t walked out of this freakshow.”
Nightbeat pinched the bridge of his nose. “Primus save me.”
Brainstorm leaned an elbow against the console, smirk playing at his lips under his mask as he watched Perceptor adjust a data model with perfect calm. “If I have to put up with this nightmare, at least the view is good. Call it hazard pay.”
Nightbeat cleared his throat loudly, dragging him back. “Focus, Brainstorm. The point is, we’re hunting a sparkeater. And you’re going to help.”
Brainstorm nodded absently, optics still glued across the room. “Uh-huh. Sparkeater, sure. Monster. Yep. Totally listening.”
Perceptor bent to adjust something on the console, plating shifting smoothly as he did. Brainstorm’s wings twitched so hard he nearly smacked a light fixture.
Nightbeat kept talking, outlining theories, procedures, witness accounts—but Brainstorm caught maybe one word in ten. His processor was too busy cataloguing the curve of Perceptor’s frame, the focus etched into every precise movement.
“Brainstorm!” Nightbeat barked.
Brainstorm jerked his helm around, caught guilty. “What? Yes! Monsters, corpses, danger! I’m all in. Sign me up.”
Nightbeat narrowed his optics, unconvinced.
Brainstorm crinkled his optics to show he was smiling, wings flicking high. “But I reserve the right to complain the entire time.”
Brainstorm smoothed both hands over his chest plating, wings flicking up like pennants. Making himself look more important than he really was. Nightbeat had gone back into investigation mode, ignoring Brainstorm’s prepping.
He strutted across the lab floor, every step rehearsed in his head, every line ready to deploy.
“Hey there, gorgeous,” he purred, leaning far too close to Perceptor’s console. “What’s a mech like you doing in a dead joint like this?”
Perceptor didn’t look up. His fingers moved across the screen, steady and precise. “Analyzing data.”
Brainstorm faltered for half a beat, then rallied. “Well, data’s cool and all, but you know what’s cooler? Me.” He tapped his own chest with a flourish. “I’m Brainstorm. Certified genius. Maybe you’ve heard of me?”
Perceptor paused just long enough to spare a glance at him. The look wasn’t disdainful. It wasn’t amused. It was… unreadable. Then his optics dipped back to the screen, silent.
Brainstorm’s wings twitched. Okay, maybe that opener was a little rusty. He leaned in closer, crowding Perceptor’s personal space. “Listen, I’ve been thinking… the two of us, side by side? We’d make an unstoppable team. Like brains and—well, more brains. Think about it.”
Still nothing. Just the rhythmic tapping of Perceptor’s fingers on the pad.
Brainstorm’s internal monologue was starting to spiral. Oh, frag, I miscalculated. He thinks I’m an idiot. He’s going to tell Nightbeat, and Nightbeat’s going to roast me alive, and this whole thing is going to implode before it even starts—
Then Perceptor finally looked at him.
And without a word, he closed his console, stood, and walked past Brainstorm toward the door at the far side of the lab.
Brainstorm blinked, wings frozen mid-flicker. “Wait—what? Where’re you going?”
Perceptor didn’t answer. He keyed open a small storage closet, stepped inside, and tilted his head just once. A silent follow me.
Brainstorm’s vents stuttered. “Oh. Oh?” His optics brightened like spotlights. “OH.”
He darted across the room before Nightbeat could notice, slipping inside just as the door hissed shut behind them.
The space was cramped, lined with shelves stacked high with sterilized kits and spare tools. Perceptor stood close, plating gleaming in the dim light. For a long, breathless second, Brainstorm wasn’t sure if he was about to get punched or kissed.
Then Perceptor dropped smoothly to his knees.
Brainstorm’s processor blue-screened.
“Wha—wait—you—you’re—”
“This closet is soundproof,” Perceptor said calmly, hands on Brainstorm’s hips already working at the seams of his plating like he’d been planning this for cycles. “I am testing a hypothesis.”
Brainstorm’s vents hitched, wings snapping rigid. “A hypothesis? What—uh—what hypothesis?”
“That you will not resist.”
Brainstorm stared down at him, utterly undone. He opened his mouth behind his mask, thought about protesting, thought about asking questions, thought about acting like he had any self-control at all.
But instead he laughed, breathless, a little wild. “Fragging right I won’t.”
It didn't take much for his plating to retract and his spike to pressurize. It was almost embarrassingly fast, but Perceptor didn't seem to care. He looked almost… hungry.
Brainstorm slapped a servo over his mask the moment Perceptor’s perfect lips closed around his spike. His wings shot so high they nearly smacked the overhead shelving.
“Primus—” the word cracked out muffled against his palm. His vents stuttered, loud in the tiny space. “Oh, frag, oh fragfragfrag—”
Perceptor’s optics flicked up, unreadable, steady, as if he were taking notes. He was precise, deliberate, every shift of his mouth calculated like he was running data models in real time. Every movement of his tongue a test.
Brainstorm’s knees buckled against the shelf behind him. He slapped his free servo against the wall, digits digging shallow grooves into the metal. “You’re—you’re killing me—”
The sound he bit back turned into a strangled laugh. He couldn’t help it. His terrible flirting shouldn't have worked. Yet here he was, getting his first ever blow job in the forensic lab's storage closet from the prettiest mech he'd ever laid optics on.
“Thank you, Primus,” Brainstorm whispered into his palm, optics squeezed shut. “Finally. Finally, someone up there appreciates genius.”
Perceptor hummed faintly, as if in dry agreement, and the vibration sent Brainstorm’s entire field sparking. He nearly yelped, wings clattering against the shelving.
He bit down hard on his bottom lip to stay quiet. Perceptor had said the closet was soundproof, but if Nightbeat hears— The thought crumbled almost immediately, swept aside by another hot rush of pleasure.
“Oh, frag—you’re—you’re too good at this,” he hissed under his breath, his servo sliding up to cover his optics. “This is unfair. Illegal. Should be—should be outlawed.”
Perceptor’s servos gripped his thighs, steadying him like he was nothing more than another experiment in need of containment. Brainstorm’s vents rattled, cycling too fast, his plating heating against the cool air of the closet.
“This is—this is history!” Brainstorm’s words tumbled out between shaky laughs. “Mark it down, greatest moment of my life, bar none! Forget quantum engines, forget stabilizers—this—this right here—”
A sharp jolt of pleasure tore the rest of his words into a choked moan. He slammed his helm back against the wall with a hollow clang, barely able to clamp down on the noise.
So instead it came out in strangled bursts. “Primus, Perceptor—don’t—don’t stop—”
Perceptor’s optics gleamed up at him, steady as ever. There was no smirk, no smugness, no indulgence. Just that same clinical detachment, as though every sound, every twitch of Brainstorm’s plating was being recorded and filed away.
And frag, if that didn’t make it even hotter.
“Hypothesis confirmed,” Perceptor murmured as he momentarily pulled off of Brainstorm’s spike, giving it little kisses and licks before taking it back into his mouth, swallowing it down like a starved mech.
“Confirmed, replicated, published!” he gasped, the words spilling out without sense. “Ten out of ten, Perceptor—keep—keep running the experiment!”
And in the back of his mind, somewhere under all the noise and heat, Brainstorm wondered—half-dazed, half-terrified—how many times he’d let himself be used as a test subject if it always felt like this. Let Perceptor lock him up and—nope! Don't think about that!
Brainstorm’s cooling fans whined as he tipped forward, plating rattling. His whole frame wanted to fold, to collapse under the intensity, but Perceptor’s grip was unyielding.
Those steady hands held him in place, firm and immovable. It shouldn’t have been as hot as it was, but frag, Brainstorm’s wings quivered like live wires. Strong. Too strong. Perceptor didn’t even falter when Brainstorm’s weight pressed into him.
“Oh, frag,” Brainstorm hissed, his voice cracking high, muffled into the crook of his own arm. “Perceptor, you’re—oh, you’re—”
He lost the words in another surge that left his optics blinding white. His vents sputtered, hips jerking, trying to warn Perceptor before he could overload down his throat—that's common courtesy, right? But Perceptor just held him firm, not letting him jerk away.
And when he finally tipped over the edge, it was with a half-choked cry he barely smothered against the mech’s shoulder, every note a squeal as hot transfluid spilled out of his spike. He couldn’t help the pathetic noises he made as Perceptor kept him from rutting desperately into his mouth, only using his servos.
He slumped down, wings sagging, frame trembling from helm to pede. Perceptor braced him, steady as a wall, sucking down every drop given to him, letting Brainstorm ride out the shudders without a flicker of strain.
“You’re so fragging strong,” Brainstorm whispered hoarsely, pressing his forehead against Perceptor’s scope, wondering if he could return the favor. His vents wheezed in disbelief, cycling too fast as Perceptor finally pulled off of his spike with a wet pop. “And you—you didn’t even flinch—Primus above, that’s—that’s unfair.”
Perceptor’s optics gleamed faintly in the low light. “You appear to have… enjoyed the experiment.”
“Enjoyed?” Brainstorm let out a weak laugh that shook his whole frame as he let his spike retract into its housing. “Perceptor, that was— that was the best fragging thing to ever happen to me. I’m going to— I’m going to build a monument. A statue. A whole wing of a museum.”
His words dissolved into breathless chuckles. He dragged himself upright with difficulty, still leaning heavily on Perceptor. “You’re incredible. Fragging incredible. I’m—I don’t even have words.”
Perceptor stood, his servos still on Brainstorm’s hips. “You flatter me.”
“I understate you,” Brainstorm countered instantly, his wings twitching as though trying to lift off even in his exhaustion. “You’re—you’re the whole damn cosmos condensed into one mech. And Primus help me, I don’t deserve this, but thank you, thank you, thank you—”
He whispered it again, softer, reverent, almost like prayer. “Thank you.”
For a long moment, Perceptor only regarded him quietly. Then, in the same calm, precise tone he used to deliver data, he said, “I find flier frames like yours particularly attractive.”
Brainstorm’s processor hiccuped. “Wh—what?”
Perceptor tilted his helm slightly, as if clarifying a variable. “Your build. Your frame design. The line of your wings. They appeal to me.”
Brainstorm’s optics went wide, a gasp hitching out of him like a sparkling caught red-handed. His wings shuddered high, trembling so hard they rattled against the shelving again. “You—you—you think I’m attractive?”
Perceptor’s optics brightened hungrily. “Yes. I would not mind making this… a recurring arrangement.”
Brainstorm made a sound somewhere between a sob and a laugh. He slapped a hand over his face, half to hide, half to hold himself together. “Frag, you’re going to make me cry in a storage closet, you absolute menace.”
He dragged his hand down, optics shining too bright, vents fluttering in disbelief. “Yes. Yes, yes, yes—recurring, permanent, forever, whatever you want. I’m yours. Done deal.”
Perceptor simply inclined his head, as though confirming a contract. “Then we have an agreement.”
Brainstorm laughed again, broken and breathless, pressing his forehead to Perceptor’s helm. “You’re going to ruin me. And I’ve never wanted anything more.”
When the door finally slid open, Brainstorm stumbled out first, trying to force his wings down into something resembling casual. He was still running hotter than he should, but frag it, he could fake composure. Probably.
Perceptor stepped out just behind him, entirely composed, striding with the same calm certainty as if they’d spent the last stretch in a lecture hall instead of… well. What they’d actually done.
Nightbeat glanced up from a datapad, optics narrowing in suspicion. “Where in the Pit did you two disappear to?”
Perceptor didn’t miss a beat. “I was clarifying certain methodological processes for Brainstorm. He expressed confusion regarding the application of forensic data to engineering extrapolation.”
Brainstorm bobbed his helm furiously, nodding like a sparkling agreeing to candy. “Y-yeah! That’s exactly it. Forensics stuff. Processes. Very complicated. Needed a visual aid. You know how it is.”
Nightbeat frowned, optics flicking between the two of them. “Alone?”
“Privacy is occasionally necessary for detailed explanation,” Perceptor replied smoothly, without the faintest flicker of shame.
Brainstorm raised a finger, ready to add something dumb, then froze, realizing silence was safer. He settled for a strained crinkle of his optics, hoping it would come off as a genuine grin to the detective.
Nightbeat sighed, muttering something about eccentric scientists, and returned to his datapad. “Fine. But next time, at least tell me before vanishing in the middle of an active investigation.”
Perceptor inclined his helm with solemn gravity. “Understood.”
Brainstorm forced a cough into his fist, wings twitching like they were itching to give him away. “Yeah, understood. No problem. Won’t happen again.”
Nightbeat gave him a long look, then shook his helm. “Just… try to keep your heads in the case. We don’t have the luxury of distraction.”
The words landed heavier than Brainstorm expected. He swallowed, guilt and exhilaration warring in his spark chamber. He nodded anyway, lips pressed tight under his mask.
Perceptor, utterly unruffled, adjusted the settings on his visor and strode back toward the workstation. “Shall we proceed?”
Brainstorm trailed after him, his spark still fluttering like unstable circuitry, but he managed to force his strut into something resembling confidence. “Yeah. Yeah, let’s proceed. With the, uh, corpse stuff. Super fun.”
Nightbeat rolled his optics. “You’re impossible.”
Brainstorm muttered under his breath, “That’s what makes me brilliant,” though his optics kept flicking to Perceptor’s aft as if pulled by magnets.
Perceptor glanced over his shoulder once, optics gleaming faintly, and Brainstorm swore the mech’s mouth twitched in the ghost of a smile.
Heat flushed through him again, but this time he kept it locked down, folding his arms across his chest and trying very hard to look like someone who hadn’t just had their processor scrambled in the best possible way.
Nightbeat didn’t press further. He was too busy with the case files, with the strange corpse, with the endless tangle of details waiting to be solved.
But Brainstorm’s processor wasn’t on corpses or data or sparkeaters anymore. It was caught in a loop of one thought: Perceptor.
And if that meant he had to sit through the rest of this job just nodding at whatever Nightbeat said while dreaming about what came after, well… he could live with that.
For once in his chaotic, impossible existence, Brainstorm felt like the universe had handed him something good. Something extraordinary.
And frag if he wasn’t going to hold onto it with both hands.