I do not own Transformers or Harry Potter.

Roll out and read on.

Harry couldn't believe what he'd been dragged into this time. He'd thought being in the Air Force would be simple, straight-forward, and he was even in the wizard-free dimension he'd accidentally discovered when someone tried to assassinate him with the Veil of Death. Returning to his homeland had been hard but not difficult to figure out-just because a world didn't have wizards didn't mean there wasn't magic, and now he knew what Stonehenge was for-and had been on several trips through it since, often with Luna and or Hermione. He'd come here again to take a vacation from magic, to fly like the muggles did, and his need to be doing something helpful led him straight to the military. He agreed to serve three years and then see where the wind took him after that. But of course Something Happened.

His friends called it the Potter Effect. He called it irritating.

Giant robots had landed on the planet and were now fighting each other for something they called the Allspark, some giant magical cube that radiated more power than he'd ever seen before. He even touched it once, had snuck all the way down through the Hoover Dam secret base weeks ago to find out what that Merlin-be-damned itching feeling was being caused by and touched the huge space cube, unable to help himself, but all that happened was a small shock to his fingertips that made them tingle for the next half hour. At least the itching feeling stopped. Now he was heading straight for a fight and their mission was to shoot down any Decepticons still standing, especially Megatron.

Something was off about that jet. Harry Potter stared at it, thinking. The robots could shapeshift to look like anything. One had disguised itself as a military helicopter to attack Qatar. If there was one... He reached out a thin, sharp tendril of magic, one fine enough not to disrupt any of the electronics if that was a normal jet, and found rushing energy where he really hoped he wouldn't have. At the back of the formation already, all he had to do was drift sideways, and then he opened fire. The transformer shifted rapidly, the fastest he'd seen any of them do it, but missed the snatch at Harry's hostile aircraft as he was already rolling out of range, catching one of his comrades instead. Harry shot him again as he reached for a second jet, then blasted away from the formation as the enemy focused on him. All his maneuvering and flight tricks preserved his F22 while the other pilots in his formation took shots until they reached the city where the Decepticon finally got in a glancing hit on his left wing that sent him spinning out of control up into the sky.

Apparently the auto-eject the seat was designed with was working just as well as his guidance systems now. With a scream of frustration, he drew upon his magic to apparate safely away from the out of control aircraft before his engines failed and he crashed. He brought his hand up to his harness to unbuckle it and free himself enough space to twist into the magical teleportation, but when he touched it, magic flooded through his fingers, making his entire arm up to the elbow tingle with a severe pins-and-needles sensation. Shocked, he really wasn't sure how to react when the cockpit suddenly started buckling and shifting, parts moving faster than he could see. He gasped when he was encased, vision black and the machine still moving all around him. The seconds seemed endless and the wizard who couldn't move to escape tried hard not to panic. He couldn't resist the transformation when his seat started moving and manipulating his position into a standing one and his harness tightened. And then the airflow to his helmet cut off.

Before he could really get to panicking about suffocation, he could breathe freely again and he could see. He could see quite clearly that he was falling. Then he learned he could move, whatever was still encasing him now moved as he did, as he reflexively brought his hand forward. And saw large metal arms come into view. He brought a hand close to his face, he could feel himself do it, and the metal hand moved accordingly. From his magic, he could feel he was still encased in metal, and realized that he was looking at a screen, a display so close to his face he couldn't see the edges of it. Belatedly, he also noticed he couldn't feel any wind across his face.

Oh, right, he was still falling. Harry brought his legs underneath him just in time to crash into the ground, and they absorbed the impact nicely. The very same robot he'd been chasing shot overhead, firing at him with machine guns. Without even thinking about it, he shook an arm, bringing his own guns to bear. An auto-targeting reticule appeared, but his shots missed wildly. The flying Decepticon disappeared, and Harry just stared at his own arms and the buildings around him. Buildings that looked much smaller. His thoughts seemed frozen, until he caught sight of a car that reminded him of the yellow one that had been at the start of this whole mess. It didn't have the black stripes, but it was enough to get his brain moving again and he realized. He was controlling his own giant robot!

That had to be one of the coolest things he'd ever seen.

With a laugh, he wades right back into the fight, learning quickly how to correctly use his transformed jet's new weapons. He immediately shot Megatron himself, distracting him from beating on Optimus Prime. The bastard attacked, sending him flying, but he'd bought Prime a few precious seconds of recovery. Then he got caught up fighting the jet-turned-mech, who would not leave him alone. He finally just landed, in humanoid form, and the pair started all out brawling in the street. Unfortunately for Harry, he was still new to controlling a giant robot and was losing to the experienced Decepticon. It wasn't long, however, until Megatron lay defeated and Harry Potter's foe fled the fight, leaving the Autobots victorious.

As he limped back to the Autobots, Harry wondered how much damage he had received and a list appeared on the left side of his display. It was a long list, sadly, but only a few of the items were highlighted in red for heavy damage, like the lower left leg. When he appeared from around the corner of a building, into sight of the Autobots, they all immediately went on alert and turned guns on him.

"Wait wait wait, don't shoot me!" Harry waved his hands in front of him, open hands that weren't transformed into weapons of any kind. "I'm not an enemy!"

Optimus Prime looked at the unknown Cybertronian standing in front of him, the one who appeared near the end of the fight and out of nowhere. One of the soldiers spoke up, saying, "I saw him fighting that flying one, the jet. You called him Starscream?"

Fighting Starscream off or not, he bore a strong resemblance to the Decepticon. None of the Autobots put down their weapons. "Who are you?"

"I'm Harry Potter." Two of the soldiers collapsed on each other as one dropped the other he'd been supporting and the guy dragged him down. Some of the other soldiers just gaped at him.

"Harry Potter is the name of one of the human soldiers, a pilot, I believe." Optimus was quite certain he was looking at one of his own kind, not a human in one of their jets.

"Yep, that's me. Ah, just a moment, hm, how do I get out of this...?" The chest plates of the Autobot claiming to be Harry Potter started folding back, opening access to the interior and revealing the spark chamber. Except it wasn't a normal spark chamber, it was larger and shaped differently. The internal chamber opened next, and they could see a figure inside, covered in a strange armor that sprouted countless wires and connections. It seemed to be supported by thick cables at the back. Finally, the face plates of the helmet split apart, revealing the face of the human Harry Potter.

The human took a deep breath of air and then waved at him. "Hello!" The arm of the cybertronian mimicked his movement.

No one really knew what to say, but the Autobots withdrew their weapons. Ratchet approached and scanned him. Then scanned him again."Optimus, these results are conflicted. They tell me this soldier Harry Potter is both human and a spark. "

All the Autobots leaned closer to peer at him curiously, including Optimus. "What happened?"

"Well, that flying Decepticon-you said his name was Starscream?-shot me, I lost control of my plane, panicked, and then it turned into this." The human looked about as confused as everyone else from what he could tell.

"Can you tell us anything else, Harry Potter?" Cybertronians didn't appear out of nowhere, yet here one was, with a human that was also somehow a spark at its center.

"Well, it felt the same as when I touched the cube. The Allspark thing. There was this tingling feeling in my hands. It was rather painful, actually."

"Wait, when did you ever touch the Allspark?" This from Sam Witwicky, who had been at the center of this whole mess since it started. He had been with the soldiers, Sector 7 agents, and Bumblebee in the secret base under the Hoover Dam. "You weren't there earlier today."

"It was a while ago." Harry Potter waved the question off, not really answering it. "I'm sorry we could not arrive sooner. Who is that?" He was looking at Jazz, the smallest of their group who was torn in half by Megatron.

Ironhide, who carried Jazz's body, answered. "This brave Autobot is Jazz."

It wasn't until an hour after cleanup started that Harry figured out how to use his radio again so he could call in that he was alive. All the other pilots who had survived were already back to base and being debriefed by then. He actually interrupted the debriefing about himself, where the pilots who witnessed it saw Starscream hit his F22, saw the F22 spin up out of control but still intact, then saw the F22 transform into a bot just like Starscream and fall into the city.

"Where are you!?"

"I'm still with the Autobots, sir, receiving repairs." He had withdrawn to the interior of his Cybertronian body when he figured out he couldn't leave it because the cables holding him there were locked in place. He was, in truth, receiving repairs at that very moment from Ratchet, the Autobot medic/mechanic, who was fixing up his leg. Maybe when that major repair was done, Harry would be able to turn himself back into a jet. He suspected that was the key to freeing himself.

Harry couldn't help but yawn, accidentally blocking whatever came through the radio next, and an alert appeared on his display. "Oy, Ratchet, what is energon?"

"Energon is our primary fuel source, why?" The medic looked up from his knee curiously.

"There's this warning that says my energy levels are critical and I need energon. Pretty sure that's a bad thing. And it's blinking at me. What is that sound?" An unfamiliar beeping was the last thing Harry Potter heard before he fell unconscious and his Cybertronian shell went limp in front of the swearing medic.

I've seen stories where Harry joins the Autobots, becomes an Autobot, becomes akin to Primus, absorbes all the Cube's power, etc. but I don't think I've seen one like this, where he is still human but can control a Cybertronian body, like a Gundam or something. So I had the spark of an idea...

To answer a few questions, Harry only received a spark when he touched the Cube, no awesome wellspring of power or anything. He will not be making new Cybertronians left and right. He is still a human wizard.

Please review, I would really like to receive comments about this idea.