Disclaimer: Not mine.

SEQUEL to 'Hot Rod's Not So Excellent Encounter', which is in turna sequel to 'Prowl and Sideswipe's Excellent Adventure'. Might wanna read them before reading this, though it's not completely necessary.

Author's Note: Perceptor and Sideswipe have invaded my brain. twitch Someone please explain to me how the most crack-filled fic I've ever written has spawned an actually somewhat decent romance fic about a very strange pair? Perceptor is probably slightly out of character, but I can't do his babbling very well. Plus having him and Bluestreak babbling at the same time would've probably caused Sunstreaker to go on a murderous rampage. O.o Also, I fail at microscope smut. So there is none. I tried, but I failed.

- Once More With Feeling -

There was something to be said for having a mobile alt form. It prevented one from having to walk when, say, the mech you went to a scientific conference with happened to get excited about an invention and forget all about you. It also prevented one from having to travel across dusty plains and deserts, since the road was most emphatically reserved for machines on four wheels and not robots on two legs.

It was therefore unfortunate, Perceptor mused as he trudged down the road, that his alt mode was not mobile. His alt mode was, in fact, a microscope. A highly advance, very powerful microscope to be sure...but not mobile. Apparently even one of the most advanced microscopes in the known universe did not rate wheels. That, Perceptor decided, would change as soon as he got back to the Ark. He didn't care how long it took him to figure out the proper schematics, or how much he had to bother Wheeljack and Ratchet about it - he was getting wheels put on his alt form. Even little ones would do, as long as they were functional.

Caught up in his fantasies of speeding down the road as a microscope on wheels, it took a few moments for Perceptor to notice the dust cloud heading in his direction, but when he did, he let out a sigh of relief as he stopped trudging along and waited for it to reach him. Wheeljack had remembered him, after all - or perhaps not.

Perceptor frowned as the Lamborghini came to a halt a few inches short of running him over, then took a step back as the red sports car transformed.

"Now what's a nice mech like you doing all the way out here?" Sideswipe purred, and Perceptor gave him a weary look.

"Apparently Wheeljack forgot about me at the conference, so I was endeavoring to walk back by myself." the scientist said. "I don't suppose you'd be inclined to give me a ride now that you're here?"

"Sure." Sideswipe chirped cheerfully, folding back into his alt form. He sped around Perceptor once, then stopped parallel to the scientist and popped open his door, engine revving madly. Perceptor gratefully dove for the seat and activated his transformation sequence, ending as a microscope in Sideswipe's driver's seat. As soon as he was in, Sideswipe slammed his door and took off with a squeal of tires. The rest of the trip back to the Ark was, unsurprisingly, quite fast, as Sideswipe most certainly broke the human speed limit on the way. Perceptor, for once, didn't mind the red twin's blatant disregard for the rules, just wanting to get back so he could spend a few hours in the wash racks, relaxing and washing away all the dust from his unanticipated hike.

"Here we go, home sweet home." Sideswipe declared, opening his door, and Perceptor tumbled out, transforming as he went.

"Thank you, Sideswipe." the scientist said with a nod of his head as Sideswipe transformed.

"No problem." he said. "Figured you could use a lift after Wheeljack came back without ya." Perceptor gave the red twin an odd look.

"You ventured out looking for me?" he asked in puzzlement, and Sideswipe shrugged.

"Had nothing better to do." he said flippantly, then leered. "Next time you need a ride, of any kind, lemme know. I won't leave you behind."

"Of course." Perceptor replied warily, then stared after Sideswipe as the melee warrior leered one last time before turning and sauntering away with a wave. The scientist contemplated the oddness of Sideswipe's actions for a moment - irrepressible flirting was normal, noticing when Perceptor might be in need of assistance and coming to look for him was not - then shook himself and headed for the wash racks. Sideswipe was not a mech whose actions often made sense, after all. And there was a clump of dirt stuck in-between two pieces of armor on his foot that was beginning to irritate the wires underneath...

--

Feeling distinctly cleaner, and much more relaxed, Perceptor left the wash racks an hour later and made his way to the rec room. He didn't often visit the place, since his lab had its own energon dispenser, but Ratchet had been threatening him lately with having that dispenser shut down if he didn't show his face around the other Autobots more often. So he went to the boisterous rec room, got his energon, and was heading out again when a large golden body blocked his path. Perceptor looked up with no small amount of dread to find Sunstreaker planted in front of him, glaring.

"Ah, hello Sunstreaker." Perceptor said, resisting the urge to look around and see if any of the officers or Sideswipe were around. Something told him they weren't, and that looking for them in this situation would be a rather bad idea.

"Hello...Percy." the nickname he couldn't quite get away from was said more like an insult, and Perceptor frowned, only to be thrown by Sunstreaker's next statement. "Why don't you join us?" he motioned off to the side, and Perceptor saw Bluestreak sitting at a nearby table, waving cheerily. Looking back at Sunstreaker, Perceptor hesitated a moment before nodding, then followed the golden warrior back to the table. They were short a chair, so Sunstreaker snatched one from the nearest other table - to the protests of the mini-bots occupying that table, not that he cared. Perceptor gingerly sat in it, giving the mini-bots an apologetic look, and then greeted Bluestreak with a nod.

"So how was the conference, Perceptor? Wheeljack came back all excited about it and has been locked in his lab so I haven't had the chance to ask him, and really I don't understand half of what he says when he talks about these conferences anyways. I'm not even sure I know what the conference was about in the first place - all those long scientific words are a bit cumbersome and tend to sound the same, and nothing like what they mean. It's much easier when words sound like what they mean." Bluestreak greeted Perceptor cheerily. The scientist, having not spent a lot of time around the gunner, had to take a few moments to process the babble before formulating a response.

"The conference was satisfactory. The humans are still many centuries behind Cybertronian technology, but their ability to adapt and learn when presented with new technology is truly spectacular." Perceptor said. "That was what the conference was about - the adaptations many human scientists have made to some of our technology. Wheeljack was absolutely enthralled with some of the ideas they came up with."

"And what about you?" Bluestreak asked curiously. Perceptor shrugged faintly.

"Methods of back-wards engineering do not exactly appeal to me. I prefer to push the boundaries of our own science, and leave others to aid the humans in achieving an level of scientific understanding equal to our own." he said.

"Don't like the fleshbags much?" Sunstreaker asked unexpectedly.

"Not precisely. I just find them a little..." Perceptor searched around for a suitably non-insulting term. He knew Sunstreaker didn't particularly like humans, but Bluestreak was supposedly quite fond of them. "Unadvanced." he finally settled on. "I will gladly work with them, but I am not fond of having to stop and explain basic scientific concepts to them."

"Like you have to do with most of the other bots around here?" Sunstreaker asked, and there was an edge to his voice that said Perceptor's answer would be important. Bluestreak was frowning faintly at the golden twin, and Perceptor picked his next words carefully.

"Explaining scientific concepts to other Autobots is a different matter. With the obvious exceptions, they are not scientists. Their specialties lie elsewhere. The humans I have to explain concepts to are scientists by trade, supposedly at the tops of their fields. It is...frustrating to suddenly have to stop and explain something to someone you had assumed would already know it. Whereas explaining a scientific concept to someone who is not a scientist is to be expected." Perceptor said, trying to put his opinion in the least offensive way possible. Sunstreaker was silent, frowning faintly, and after a moment, Bluestreak spoke up again, telling Perceptor about an outdoor concert he, Jazz, and Blaster had gone to the other night. Sunstreaker didn't speak again except to say goodbye when Perceptor excused himself once he'd finished his energon.

As the scientist walked to his quarters, he couldn't help but wonder whether or not he passed the test, and just what he was being tested for, anyways.

--

"So whatcha doing today?" Perceptor started in surprise when Sideswipe suddenly appeared beside him as he walked towards his lab.

"I had a few experiments I was thinking of attem-" Perceptor was cut off as Sideswipe suddenly grabbed his arm and dragged him down a hallway to the left, leading away from his lab.

"So, nothing. Excellent!" the red twin said cheerfully, and Perceptor glared at him.

"Attempting to analyze several strange metals Cosmos retrieved during his last mission is not 'nothing'." the scientist said.

"No, but I checked the schedule, and it's your day off, so you don't really need to analyze those materials." Sideswipe declared. "Which means you're coming with me."

"Where?" Perceptor asked grouchily. He'd been looking forward to analyzing those metals.

"It's a surprise!" Sideswipe said brightly.

"Sideswipe..." Perceptor started irritably, then paused at the look the red twin turned to give him. It was, without a doubt, the 'poor little orphan' look that Ratchet and Prowl both complained so vehemently about right after Sideswipe got away with something outrageous. According to them, Sideswipe only used it when he really really wanted something, and it was next to impossible to resist. Perceptor found himself agreeing with them as he gave in with a sigh. "Lead the way." he said, and Sideswipe grinned brilliantly before continuing to drag Perceptor through the halls out of the Ark. Sideswipe transformed quickly when they reached the entrance, opening his driver's door and revving his engine. Perceptor sighed once more as he activated his own transformation sequence, and soon enough he was safely secured in Sideswipe's front seat, while the red twin took off into the desert at top speed.

"So do you always work on your days off?" Sideswipe asked as they went.

"It is what I prefer to do when given a choice." Perceptor replied.

"You enjoy working?" Sideswipe questioned with a little incredulity.

"Yes. Don't you?" Perceptor replied, more because it seemed like the polite question to ask rather than because he wanted to know the answer - it was fairly easy to guess the red twin's response, at any rate.

"No." Sideswipe said, unsurprisingly, after an odd pause. He waited for another moment before speaking again. "I doubt anyone but a Decepticon would considering killing other mechs for a living enjoyable, anyways." Perceptor mentally winced - he hadn't stopped and thought about just what the red twin's job technically was these days. He had no problems fighting, but he was by no means a regular combat mech, and sometimes, the war became rather distant to him.

"I apologize, Sideswipe, I didn't mean to imply that you would enjoy killing." Perceptor said uncomfortably.

"Heh, no problem. I did enjoy what I did before the war, but that was a long time ago. And even then, I didn't work on my days off." Sideswipe commented.

"And what did you do?" Perceptor asked curiously. It was rare to get one of the twins in the mood to talk about what they did before the war, and Perceptor couldn't help but wonder just what the Autobot's two strongest melee fighters had done on a peaceful Cybertron.

"I was a merchant. Quite a successful one at that." Sideswipe replied easily. "Almost a tenth of the building supplies imported or exported from Kaon went through my business. Of course, those sorts of businesses were the first ones hit by the Decepticons when they came looking for supplies. I was in the first wave of mechs to be put out of business by the war."

"I'm sorry." Perceptor said, slightly stunned. He'd had no idea.

"Eh, it happened a long time ago. Over it now. Besides, Sunny and I had a good chuck of credits saved up. We figured we could live off those until the 'little rebellion' was put down." Sideswipe said. He was silent for a moment. "Of course, then we found out we couldn't access those credits unless we signed up with the Decepticons."

"What did you do?" Perceptor wasn't sure he wanted to know, but with morbid curiosity, he asked anyways.

"There wasn't much we could do. The Cons had shut down the city by that point, so we couldn't leave. We had no credits, and we didn't want to sign up with the Cons. The only place left was the Gladiator Pits." Sideswipe replied. His tone was steady, almost light, but Perceptor was sure that this subject couldn't be comfortable for the red twin - why else would he and his brother never talk about their past? - so he didn't question further. He'd heard enough rumours about the Gladiator Pits of Kaon that he didn't really want to question further, anyways.

"What about you, Percy? What'd you do before the war?" Sideswipe asked after a few minutes.

"Much the same." Perceptor replied. "I was one of the lead researchers at the science academy. I was barely aware the war was even happening until I was recruited to help build weapons to defend against the Decepticons." Sideswipe chuckled.

"Quite the difference." he commented, and Perceptor made a noise of agreement. "Oh well, we both survived. And now we've both arrived!" Sideswipe slid to a stop, opening his door and allowing Perceptor to transform out of him before transforming himself. Looking around, Perceptor saw that they were near the edge of a canyon out in the middle of the desert, and he frowned over at Sideswipe. The other mech grinned back at him, then headed for the edge of the canyon.

"Come on, it's down there." he said.

"What is?" Perceptor asked, following him.

"What I brought you out here to show you." Sideswipe replied, peering over the edge. Then, suddenly, he stepped off the edge, and disappeared. Perceptor rushed forward with a surprised cry, only to relax as he saw Sideswipe grinning up at him from a ledge not far down. "Come on, there's enough ledges that we can jump our way down."

"And how do you intend for us to get back up?" Perceptor asked with a frown.

"I have this thing, it's called a jetpack..." Sideswipe drawled, and Perceptor sighed. Of course. He'd forgotten all about Sideswipe's jet pack. And since they now had a way up, he had no excuse but to go down. So with resignation, Perceptor carefully let himself fall over the edge, aiming for the same ledge Sideswipe was on. He landed a bit unsteadily, but Sideswipe was quite prepared to catch him, wrapping his arms around the scientist and keeping him from losing his footing. Sideswipe wasn't exactly in a hurry to let go, of course, and Perceptor had to push a bit to get himself out of the red twin's embrace. Sideswipe smiled innocently back, then went to the far side of the ledge and jumped off again.

Perceptor sighed as he looked over the edge, and found Sideswipe grinning up at him from another ledge. The red twin had probably picked this path on purpose, the scientist mused as he once again stumbled on landing, only to be caught by Sideswipe. He decided to ignore Sideswipe's growing grin as they made the last two jumps down into the canyon, each time Sideswipe 'steadying' Perceptor when he landed. The scientist irritably wondered why he'd agreed to come out here again, only to flashback to Sideswipe's pathetic 'poor little orphan' look and remember why. And it was only once they were on the canyon floor that it occurred to Perceptor that, in order for him to get back up, he'd have to hold onto Sideswipe. He held back a groan as Sideswipe grabbed his hand and dragged him off down the canyon.

"Shut off your optics." Sideswipe suddenly ordered, stopping and turning.

"What?" Perceptor asked in surprise.

"Shut off your optics." Sideswipe said patiently, and Perceptor gave him a suspicious look, well aware of the lengths Sideswipe would sometimes go to for pranks. "I swear on my brother's spark that this is not a prank." Sideswipe said, evidently understanding the scientist's hesitation.

"Very well." Perceptor said, and obligingly shut off his optics. He didn't bother to mention that he could, to some extent, still see through the microscope barrel on his shoulder, instead letting Sideswipe lead him a little ways further before suddenly turning them into the canyon wall...and into a cave. Perceptor stopped trying to see through his microscope barrel at that, knowing there wouldn't be enough light to get anything useful, so he just let Sideswipe lead him along. It was several minutes before the other mech stopped, coming to stand behind Perceptor.

"Alright, you can look." he said softly in Perceptor's audio, and the scientist obligingly turned on his optics - and then gasped. The cave around him was huge, with stalactites and stalagmites easily twice as tall as Prime himself. Phosphorescent moss covered the walls, while not far away, a small underground stream wound across the cave floor. Even more interestingly, what rock could be seen underneath the moss glittered with an unknown metal or crystal, and Perceptor itched to find out what it was. It probably wasn't anything special, but the scientist in him wanted to find out what it was just because. Still, there was one thing stopped him - the nagging question as to why Sideswipe had brought him down here. As much as he enjoyed having the chance to see it, and wanted to catalogue everything in it, he couldn't help but think that Beachcomber would appreciate it more.

"Like it?" Sideswipe asked, bringing Perceptor's attention back to him, and he found the red twin leaning against the cavern wall, smiling faintly.

"It is quite stunning." Perceptor said, then gave the twin a curious look. "Why bring me here, though?"

"It was nice. I figured you'd enjoy seeing it before I tell Optimus about it, and he tells Beachcomber and the humans, and they come in here and tromp all over everything." Sideswipe said, waving a hand.

"I'm sure they'd be careful not to wreck it." Perceptor replied, and Sideswipe shrugged.

"Whatever." he said, then pulled a cube of energon out his subspace and took a careful sip of it. "But I doubt you'd bother to come down here once they were investigating everything."

"True." Perceptor murmured, cautiously reaching out to touch part of the wall covered in moss. It was cool, but soft, and Perceptor curiously activated his microscope barrel again, peering into the cells of the moss as he tried to figure out what kind it was, and why exactly it was glowing. He quickly became absorbed in the moss, and then the rock behind the moss, and from there he tried to determine the age, and so on and so forth, new things catching his attention each time he finished with something else, and it was hours before he recalled that he wasn't down there alone. Surprised that he hadn't heard a complaint before now, Perceptor turned, searching for Sideswipe, and found the red twin sitting at the mouth of the cave they'd entered through, an energon cube in one hand and a data pad in the other, apparently reading.

"Sideswipe?" Perceptor inquired as he approached, and the red twin glanced up.

"Finished poking around?" he asked.

"For now. What are you reading?" Perceptor asked curiously, moving in an attempt to see.

"Just some human stuff. Bluestreak's got Sunstreaker reading some of it, and he keeps ranting to me about how boring it is, so I figured I'd see what he's complaining about." Sideswipe said with a shrug as he put away the pad before Perceptor could see what was on it.

"Oh." Perceptor said, slightly put off by the abrupt rebuttal when Sideswipe had been so open with him today. But then, he had just ignored the other mech for a few hours in favour of a cave. A very splendid cave, but still a cave.

"So are you ready to go back, or did you want to look around more?" Sideswipe asked.

"I could spend hours more here if I had a few pieces of equipments with me, but unfortunately they're back at my lab. I'm sure waiting while I poke around a cave isn't exactly your idea of a good afternoon, either, despite having brought me down here." Perceptor replied, adding the last part as a form of apology for ignoring the red twin.

"I had stuff to read. And besides, it's quite pleasant down here. Especially with you here." Sideswipe said cheerfully as he pushed himself to his feet, subspacing his half-empty cube of energon as he went. Perceptor gave the twin an odd look. He hadn't missed the fact that Sideswipe's usual flirting had been missing today, and to have it suddenly come back in the form of a compliment, well...

"Sideswipe, why did you bring me down here?" Perceptor repeated his question from earlier, this time watching the red twin intently. Sideswipe looked back with a fake smile, and Perceptor arched an optic ridge, silently daring the red twin to try to lie to him again. Just because Perceptor preferred to spend his time in his lab, away from the other Autobots, did not mean he was naive or inexperienced, as Sideswipe well knew.

"Uh..." Sideswipe's smile faltered as he looked back, and then unexpectedly looked away, fidgeting slightly. "I thought you'd like it." Perceptor waited, but that was apparently all Sideswipe was going to admit to, shaking himself and turning back to the scientist with the fake smile in place again. "We should head out if you're done. It's getting late." With that, he turned and started heading up the cave they'd come in through. Perceptor hesitated only a moment before jogging after Sideswipe. Before he could over-think what he was doing, Perceptor caught the other's mech's arm, pulling him around as he used Sideswipe's arm as a brace to push himself high enough to plant a brief kiss on the red twin's lips.

"Thank you." he said, locking optics with Sideswipe. The other mech hesitated only few moments before leaning down to return the kiss, this time more heat, though it was surprisingly chaste for Sideswipe.

"You're welcome." Sideswipe breathed as he pulled away. Perceptor almost let it go at that - he wasn't usually one to jump straight into interfacing in a relationship - but his scientific side had perked up, wondering just what the differences were between Sideswipe's normal frame and that temporary femme one. So he hauled the other mech back, kissing him deeply even as one of his hands dipped underneath Sideswipe's chest armor, looking for a particular bundle of wires he knew had been quite sensitive last time. As the larger mech shuddered under his fingers, Perceptor filed that spot away as still sensitive, and caressed it once more before moving on to the next spot...

Meanwhile, far away in the Ark, Sunstreaker twitched violently and fled from his quarters, in desperate need of a distraction in the form of one very talkative gunner.

- END -