This fic is based on 2 prompts from the latest Transformers Kinkmeme.
PROMPT #1: "It's pretty obvious Cade is working really close to Optimus' spark chamber when he's repairing him in AOE. What if Cade accidentally crosses some wires and causes Optimus to be stuck in a state of constant arousal? And what if the repair work makes Optimus have repeated overloads?"
PROMPT #2: "What I'd love is seeing Cade realizing he has feelings for Optimus, and trying to keep it to himself. But he's doing a bad job of it. He gets flustered and nervous and trips over himself around the bot, he's completely foolishly in love. Optimus knows and loves him for it, he thinks it's endearing. At some point there's a revelation and Cade is still completely a wreck but Optimus takes care of him. It can be sexual or not, but if it is, I would prefer bot on human, not holoform (or a robotic looking holoform instead of a human one.)"
There is no shipping or romance in this chapter, but there will be in later chapters.
"OK, big guy, settle down. We're gonna be here a while."
"I am settled," Optimus replied with his usual calm pragmatism. He had recently seated himself upright against one of the support beams. His blue optics were trained on the weary mechanic, who had just maneuvered his ladder into the right position. "Cade, I must point out that you are more likely to tire than I am. If I were to lie down -"
"Then I'd just as likely fall into your chest as fix anything," Cade replied. "This way I may be twisted around a little, but at least I can reach. And when I can't, I can step forward onto you as opposed to falling in." He paused, one hand on the top rung of the ladder, the other reaching for the stained sweat-towel draped over his right shoulder. "I've pulled all-nighters before. I'll do it again if I have to. We may not have a lot of time."
Optimus did not reply to this. He knew what the human meant, but Cade could not know that Transformers reckoned time far differently. For a bot, it could be Earth months or years between powerdowns. He recalled with amusement how startled he had been to learn that humans had to spend approximately one-third of their lives in a sort of low-grade shutdown mode. He had at first thought their entire race was sick or injured in some way, until Rachet pointed out the comparison between their cycles with that of other diurnal mammals of their planet.
His thoughts were interrupted by the pain. He had purposefully not told Yeager that normally he'd be unconscious for this sort of surgery. He did not want to inhibit the human with a fear of harming him. Almost nothing Cade could do would be worse than what had already been done to him. And this time, he was ready for it. Optimus felt the sting of new connections firing, the ache of old exposed cables grinding painfully together... and bore it silently. If he groaned or twitched, he could startle or dislodge the small, soft-bodied creature working on him.
The heavily-protected spark chamber emitted a soft buzz that Cade felt more than he heard. The hair on his arms stood up when his hands moved close to it. He shook his head slowly when he realized just how much damage Optimus had taken. These guys are practically indestructible, he thought. What kind of missile could almost kill one of them? Prime's armor was so hard that none of his drills or saws made the slightest dent. Optimus had had to pry his own chest open wider so that Yeager had room to work.
The job had looked incredibly complex, he mused, till he stopped thinking of it as machine repair and started thinking of it as a kind of mechanical surgery. This hose (vein?) was meant to carry Energon to that temporary storage tank down there (a sort of stomach?). A clamp would temporarily stop that leak until he could grab something to patch it. And there. This cable looked to have been severed, and if so, its other end was right back there... how to connect them again? He tugged experimentally to see whether he could coax either one out further.
Suddenly he yelped and clutched wildly at Prime's chest for balance as the once-stoic Autobot shuddered and gave the deepest of groans.
"Optimus! Optimus, are you okay?" He looked at the base of the ladder; luckily, both sides were still planted firmly on the ground, straddling the bot's left leg.
Optimus gave another brief moan, then fell silent. His optics were shielded. For a moment Cade feared he had somehow killed him.
Then the blue optics were exposed again. The giant bot tilted his head back and gazed at the roof of the barn. "It is nothing. Please ... continue."
Cade hesitantly reached for the cables he'd been trying to connect - they stubbornly seemed to retract, as if aware of his touch - and looked up at Optimus' face again. "Are you sure? You sounded like you were hurt."
"I apologize for disturbing your work," Prime replied. His voice sounded strained. "I assure you it is nothing I cannot handle. I will not dislodge you. Please continue."
Cade nodded. He reached for a thick copper-alloy cable that seemed like it would be the best available conductor for the two stubborn severed ends he was trying to connect. His emotions shifted wildly between fear of some energy surge shocking the fuck out of him if he misjudged, hope that he wasn't hurting Optimus, self-assurance at his ability to repair any machine, and the deepest humility at being privileged to explore and repair the alien biology of this gentle, sentient being. Optimus' functionality, and therefore his life, was in Cade's hands. Fleetingly he remembered the feeling that had come over him when the nurse had first placed Tessa in his arms.
"Hope you're not allergic to copper," he murmured, and picked up the soldering iron from the detachable storage shelf.
To Cade's dismay, Optimus shuddered again while he was working, so lightly that Cade at first wondered if he had imagined it. And again, once the second connection was in place. When Cade removed his hands, Prime gave a groan so deep that Cade felt it rattle the blood within the chambers of his own human heart. He gasped, grabbing the top of the ladder. A low mechanical whine below his feet alerted him to the fact that both Optimus' beautifully articulated hands were clenched into fists. When he looked up at Prime's face, the Autobot leader's optics were once more shielded.
"Prime?" Cade whispered, and then cleared his throat. "Optimus?" he queried loudly.
Optimus' optics focused on Cade again. He unclenched his hands and lay them down at his sides.
"Optimus, what's wrong?" Cade was genuinely alarmed at this point. The Autobot still didn't answer. "Optimus?"
The initial surge had been bad enough. Prime was in control of his emotions at all times, but having his own biological drives turned against him was something he had never expected. The human could not know of his arousal, he thought desperately. He didn't know what he'd done. It would only harm him if he became aware of the distress Optimus felt. Optimus sensed they were almost finished with the major repairs. He fought to keep his upper body still as another overload surged through his massive body. He must be able to move and fight again; that was paramount! He was a Prime, Called to lead, built to serve, veteran of countless battles. He could endure this situation. Nothing was leaking; none of his vitals were spiking. He would be free soon enough to seek Rachet's help to fix the problem - surely the canny medic was alive somewhere, or... He lost the thought as his pelvis twisted in sweet agony and his hands clenched into fists once again.
"Cade Yeager," he gasped. "I assure you, I can handle..." He stopped for another few seconds, his head falling back against the support beam. "I can handle any pain. I will not disturb your work. Please continue."
"We're almost done," Cade feverishly assured him. He placed a few more clamps, tested some connections. In what felt like an eternity to the Autobot, Cade leaned back against the ladder and looked up at Optimus. "I've repaired everything I could see. Can you test - test yourself out?"
Optimus sighed and shuddered again, then seemed to collapse into himself. Wearily, he informed the human, "I will test my mechanisms only once you have removed yourself and your equipment."
Cade detached and folded the storage shelf from the ladder, throwing everything hastily into a large grease-stained tool bag, and descended in record time. He picked up the ladder and dragged everything away from the autobot. Optimus was acting strange; stranger than he'd been before the repairs. What if the titan malfunctioned somehow, and became violent again?
"I'll just leave you alone for a little while," Cade said in what he hoped was a soothing tone.
"Yes," Prime growled as he staggered to his feet, "that might be for the best."
Yeager performed an abrupt about-face and practically ran out of the barn, stopping only to bar the doors behind him. He couldn't shake the feeling that he'd done something wrong. Optimus seemed weaker, somehow trembly in his movements.
If he's hurt, Cade thought feverishly, I'll never forgive myself.
If he's hurt, what the hell else can I do?
Even with his chest still partially open and another overload threatening, Optimus Prime could and did test his abilities to transform, arm himself, and perform battle maneuvers. His dexterity was incredible considering how damaged he had been. There were some numb spots on his limbs and torso due to the alien metals Yeager had used for patching, but they were relatively small.
And oh, how he wished that some other parts would go numb. Never in his long, long life had Optimus so heavily regretted that Transformers' bodies were able to feel pleasure. The ultimate pleasure - sensory overload, the ultimate way their species shared intimacy, partnered, forged bonds of love. Only here and now, there was no partner to bond with. Here there was only his own body, betraying him. He could only concentrate on one thing ... trying to control his arousal. And his resistance was weakening.
Finally, Optimus Prime collapsed to his knees and surrendered. Another overload, then another, surged through his mighty frame. Shuddering and swaying, he ran his articulated fingers up and down his body, delighting in the delicate sensors, the beautifully tough armor, the wonder of Primus' creation. "By the All-Spark," he groaned aloud.
Cade had been unable to resist watching what Prime would do to test his abilities. How many people were lucky enough to work on a living Transformer, much less watch one in action? Peeking through the barn doors, he clapped a hand over his mouth to keep from gasping aloud. Optimus had fallen to his knees, but did not seem to be hurt. In fact, he seemed...
"Oh my God," he whispered into his fingers, just as Optimus called upon his own deity in a voice lost to pleasure.
Cade hadn't been hurting him. He'd been... helping him. Sort of.
His cheeks aflame, he thought back quickly to the repairs he'd made. When had Optimus started expressing his - discomfort? It had to have something to do with the copper-alloy cable he'd soldered into place. Maybe those two "ends" were meant to stay disconnected.
Did Optimus even know what precisely was causing it? Any more than Cade knew what caused headaches, or why aspirin worked?
As the giant mech climbed to his feet again, still trembling, Cade decided it was time to step in.
"We can't close you up yet, big guy," he proclaimed loudly, barging back into the barn as if nothing had happened. "I was thinking over what I did, and there's something I need to make right."
"Indeed?" Prime's hot-blue optics fixated on Yeager with an expression that somehow combined yearning, pleading, and desperate hope.
"Yes. That last cable I soldered together," Cade went on smoothly, grabbing the ladder, the shelf, and his toolbag. "I'm not convinced it was the right metal. It felt like it was getting too hot."
To Cade's intense relief, the giant Autobot did not protest, but meekly seated himself against the support beam once more. Cade placed the ladder over Optimus' leg again, climbed up, attached the shelf, and laid out the equipment he would need.
He steeled himself and applied the soldering iron to the copper-alloy cable. He felt Optimus jerk slightly. There was a rush of air, a blur on either side of the robot's body, and a loud clang, and suddenly Optimus was gripping the support beam with both hands over his head. Before Cade could react, Prime murmured, "Merely a precaution. Please continue."
Just before the connection was severed, Cade saw and felt one more massive shudder overtake Optimus' massive metal frame. Cade jerked his hands and his tools out of the way just in time, grabbed the ladder, and prayed that Optimus would keep his legs still and not send him flying.
Soon enough, things were calm again. The Autobot leader's optics remained shielded as Cade removed the alien metal from the Transformer's body. Looking closer, Cade saw that the cables inside Optimus' chest, which he had orginally thought raggedly severed, were actually "wired" with tiny connectors of their own... and felt stretchier, somehow, than they had previously. Luckily, it seemed his soldering iron wasn't hot enough to harm them. He wondered if anything on Earth could, short of another missile.
"I think we're done here," he breathed. "For real this time." Again, he gathered his equipment and climbed down. "Care to try yourself out again?"
Optimus unshielded his optics and trained them once again on the inventor. "No, Cade Yeager," he replied. "I can feel that I am well now." As Cade watched in amazement, the giant metal arms descended, and Optimus' fingers labored to push his chest plates back into proper alignment.
It seemed to take longer than Cade thought it should. Then again, what did he know?
"I will be forever in your debt," the Autobot rumbled. He crouched low so that he was somewhat nearer eye-level with Cade, his expression serious. "I mean it, Cade Yeager. With all my Spark."
Unexpected tears sprang to Cade's eyes. He suppressed them manfully and clasped his hands behind his back. "It was an honor to work on you, Optimus Prime." His heart swelled with gratitude he wished he had the words to convey.