This fic was written for the 2022 SuperBat Reverse Bang (with accompanying art on AO3) and would not exist at all if not for all the inspiration and encouragement I got along the way.

I signed up for the SuperBat Reverse Bang in search of inspiration, which I've been feeling a lack of in recent months, and though I wasn't able to claim a piece of art, the mods generously gave us unmatched authors the chance to form Tandem Teams of our own.

The real genius behind this fic is Gement (on AO3), who had the brilliantly mad idea to bring different incarnations of Superman and Batman together, and who joined me in the wild throes of brainstorming to turn that idea into a plot. I only regret that I didn't have the time or energy to carry the crossover even further, but I hope you enjoy what resulted.

Of course, turning an idea, however fleshed out, into a written fic is not an easy feat, and I would have thrown in the towel before the plot even got off the ground if not for the encouragement of the amazing profoundalpacakitten (on AO3) whose ideas and illustrations gave me a beautiful resolution to work toward.

6:00 am

The radio crackled to life. "Good morning, Metropolis!"

"It's time to get up, sleepyhead."

A quiet groan, followed by the rustling of sheets.

"- if you don't get down here this instant!"

"I don't care what you say!" Her voice cracked.

"... the bus should have been here five minutes ago…"

"... who orders pizza at six in the morning?"

"... you call that a pothole? It'd sure be nice if someone'd bother to send us out to fix up the streets in my neighborhood…"

"- Wait!" "... holding up traffic!" "How are you-" "... needed it yesterday!" "Who does he think-" "Excuse me…" "... ready to…" "It's not like-" "Hey!" "What's the…" "- I ordered…" "When will…" "... I'm sorry…" "You'd better-" "... please…" "How could you…"

"HELP!"

Clark's eyes opened.

The car swerved at the last minute and crashed into a lightpost. A little damage, but nothing more than a few broken bones.

Clark could feel every fiber as he tossed aside the sheets and pulled on a pair of pants, the unending buzz of city life resounding in his ears; noise drowning out noise. As he absently brushed his teeth, he risked a glance up. On the other side of the thin ceiling of his apartment, beyond the upstairs neighbors and past the blue sky where it turned into black outer space, all was quiet. No need for Superman.

Clark sat down to a hasty breakfast.

"... front coming in from the east, and tomorrow…" the upstairs TV blared.

"I'll just have to be late-" The man on the first floor called into work for the second time that week.

"Come on, come on!" The woman at the corner tapped her foot impatiently as the crosswalk counted down.

Click. The quiet sound of the safety of a gun cut through the din.

"I'll tell you one more time…"

It was just a few blocks away.

"I didn't mean it, I swear!" the man pleaded on his knees.

"That's what you said last time! I won't let it happen again!" Tears streamed down her cheeks, the gun shook in her hand.

"Please!"

Clark wouldn't even be late for work.

The gun went off with a resounding bang that no layers of insulation could dampen. She broke down in tears, which echoed no more quietly than the gunshot.

He let out a long breath. It was never so simple. He had heard them arguing- fighting before. What would his interference tell the world? It wasn't his place. He had to let humanity choose for themselves, to trust them to do right of their own free will.

He piled the dishes in the sink for later and finished getting ready for work. Clark Kent, reporter for the Daily Planet, stepped out into the hallway.

Laying on the ground at his feet was a small manilla package. The paper was rough to the touch, but the shape it was bent into was strangely smooth. It smelled faintly of expensive stationary and fruit candy, and underneath that, of metal.

On the other side was scrawled, "Show them what you really are."

He stepped back inside and tore open the package and didn't have time to brace himself for the blast.

–

"Is it a bird? Is it a plane?"

He fell through bright, open air, plummeting toward the ground. He only just had a chance to brace for impact as the even grid of city streets, scattered with gawking bystanders, rushed to meet him. In the final instant, his descent slowed just enough for him to land on one knee on the pavement.

The aftershock rippled through his body and a web of cracks spread out across the asphalt from the impact, but there was no crater, and only a little dust settled around his feet.

"Excuse me, but you look a little lost." The voice sounded as though it came from some distance, beyond the ringing in his ears.

People, all well dressed, were beginning to crowd around him, watching with uncertain eyes. At the front was a woman, nervously clutching her purse.

He raised his head, his gaze fixed just above the heads of the assembled crowd.

"Can we help?" the woman asked.

The initial blast had blown away his clothes, leaving him with only his costume. Who would think to offer to help Superman?

"I…" he faltered, his forehead creased in confusion.

"That's quite the get-up." A man approached, his hands casually in his pockets, but his shoulders set; he was afraid. "What do you call yourself?"

A child chimed in with a taunting lilt, "Where'd you come from, mister?"

Their suspicions were all too familiar, but it was almost like they didn't recognize him.

He hovered to his feet to stand before them. "I'm Superman. I come from the planet Krypton."

There was no dawning recognition. If anything, the reminder seemed to spark more confusion as the crowd erupted into chatter.

"Oh my word!"

"An alien?"

"But why here, mister?"

Amid the restrained commotion, a police officer pushed his way to the front. "Now see here, Mr. Super-Man, you'd better explain yourself!"

The rest of the crowd nodded along with the officer's stern admonition and stared expectantly, muttering among themselves as they waited for an answer that he didn't have.

"What is he doing here?"

"What does he want?"

Superman shouldn't have been there at all.

Before anyone had a chance to question him further, he lifted up off the ground, into the bright blue sky, startled exclamations trailing after him.

He rose until their voices faded into the din of wind, and traffic, and all the lives of all the people teeming in the city below. Gotham City sprawled out beneath him. He knew it was Gotham, but gone were the lofty tenements and gothic skyscrapers for which the city was known; it was all sprawling, low-lying suburbs, scattered with municipal buildings in grecian white marble. The city docks butted up against the bay, and on the other side where Metropolis should have been, there was nothing.

Up and up Clark went until the blue of the atmosphere began to fade away and he looked down upon the entire continent, from Gotham in the West - not on the Great Lakes where it belonged - to New York in the East, but Metropolis was nowhere to be seen. An entire city of eight million people had been scoured from the face of the Earth and not even a scar on the landscape was left behind. All was at peace. Beyond, the ink black expanse of space was quiet for lightyears in all directions. Even most of the satellites that usually hovered around the Earth were gone.

Again he had been so preoccupied by the cries of each individual person that he hadn't noticed the greater danger lurking right beside him until it was too late, and even now he still didn't know what had happened or whether it might happen again.

He descended back toward the city below, full of people carrying on with their ordinary lives, apparently in perfect ignorance.

"How do you do?"

"Fine weather today, isn't it?"

Only a few urgent voices were just beginning to spread the word. "Have you heard?" "He fell right out of the sky!"

Almost louder than all the people was the crackle of countless radios, "... he rounds the bases, and he's out! An upset for the… California dreamin' on such a winter's day… today General Secretary Brezhnev announced that the USSR…"

Meanwhile, every television broadcast in unison, "... strange new worlds and new civilizations…"

"Extra! Extra! Man From Outer Space Lands in Gotham!" A paper boy waved a copy of the latest edition of the Gotham Globe over his head, a black and white photograph of Superman emblazoned across the front page.

Clark's gaze leafed through it in an instant. There was not a word of Metropolis anywhere, as though not a soul in Gotham had so much as noticed its sister city across the bay's sudden passing.

It was only with a brief parting glance that Clark noticed, just below the name of the paper, the date, "July 30, 1966."

It wasn't that he had landed in the middle of the financial district; everywhere the men strolled down the streets in suits and hats, and all the women wore skirts, and there was not a cellphone in sight. All the colors were brighter; neon, geometric designs popped from dresses and furniture alike, though Clark's view inside the buildings was interrupted by lead piping and distorted by lead paint. It wasn't 1938, but maybe even the Planet still stood for something more than puff pieces and growing ad spots - if it hadn't vanished with the rest of Metropolis.

"Attention, Super-Man!" an amplified voice suddenly called to him from below. It almost sounded familiar. "I am Batman, a representative of the human race!"

It would have made for a tasteless joke. A man stood on the side of the street, shouting up at the sky through a bright red megaphone. He was wearing purple tights, with a small, yellow-framed bat symbol on his chest, and a black cape and cowl, which may as well have come from a costume store, complete with drawn-on eyebrows. Next to him was a teenager standing seriously, his arms crossed over a bright red vest, with nothing under it but green underwear, and a golden cape hanging from his shoulders.

Luthor had tried to strew discord between Superman and Batman before. Nothing he did should have been a surprise anymore.

Clark swooped toward the ground, prepared to demand answers, however, before he reached the rooftops, he saw that the man's cowl was not lined with lead, and he knew the face underneath. This was no actor hired to perform a tasteless caricature, it was Bruce dressed in a caricature of his own costume. Clark had no doubt that it was Bruce, but it wasn't just his costume that was different; his face looked younger, and even through the costume it was plain to see that he wasn't in crime fighting shape.

Bruce continued, his voice recognizable, but distinctly lighter, "We are a peaceful people, and we look forward to meeting you! Please come down, I'm sure we have much to talk about."

Some bystanders had stopped to stare, but most merely continued on with their ordinary business. He heard no whispers in preparation to spring a trap or the click of rifles falling into place. The passers-by concealed no bombs or weapons of any kind in their outdated suits and dresses. The only things obscured by lead were the pipes snaking through the buildings and underneath the streets.

"Attention, Super-Man!" Bruce called out once more, his megaphone raised to the sky.

Superman may have been elusive, but a public appearance from Batman was unheard of. Bruce must have had a plan.

Deliberately, Superman descended to the street below.

One by one, peoples' eyes turned to the sky. Superman regarded each of them.

"It's him!"

"Is he really from outer space?"

"I wonder what it is he wants."

"Welcome to Earth, Super-Man," Bruce said, holding out a hand in greeting as he proclaimed through the megaphone.

This must have all been staged for some greater purpose, but Clark was surprised by the earnest warmth in Bruce's voice. He almost wished that this was how he had first landed in Metropolis.

"Thank you for visiting our small blue world. We hope to make your stay pleasant and increase mutual understanding. To what do we owe the pleasure?"

This welcome was not really for him, but for all of the people watching him with expectant eyes, and for the rest of the world which did not yet know. "I come in peace. I am here to bring hope to the people of Earth."

Bruce exchanged a glance with the young man who stood beside him, and whispered, "See, Robin? What did I tell you?"

Clark knew the name Robin. The whole world knew that name. It was still synonymous with all that was wrong with Gotham City. Clark only vaguely recalled hearing the news at the time, and Bruce never mentioned it, but he had seen the costume enshrined in a glass case in the Batcave, the taunting bright yellow spray paint a constant reminder of Batman's greatest failure.

The young man smiled back at Bruce, cheerful and lively in every way that the Dark Knight was not.

Bruce raised his megaphone again. "Thank you. If you are our friend, we are happy to be yours."

Superman nodded, but Clark was no clearer on Bruce's plan. He landed just opposite Bruce, only a couple feet away and quietly prompted, "Batman?"

Instead of giving him a subsonic briefing, Bruce answered determinedly into the megaphone, almost as though they had been bugged, but Clark couldn't see anything of the sort on him, "Yes! I am Batman, and this is Robin, the Boy Wonder. Is Super-Man your name, or a rank of some kind?"

It was just what the press had decided to call him, but that hadn't happened yet. "It's what I go by," Clark answered solemnly, and took another step closer to Bruce to try again. "Do you know what's going on here?"

Again, Bruce proclaimed, "We are extending an olive branch to you, our first visitor from the stars. There must be so much we can learn from each other."

"Can we talk?" Clark hissed.

"Of course! It may take us a while to gather appropriate world leaders, but in the meantime, Robin and I will be happy to act as ambassadors and show you around. We'll gladly answer any questions you may have about our planet and cultures."

"Do you know what happened to Metropolis?"

Clark was met with a pair of blank stares.

Bruce quickly recovered. "This is our fine metropolis of Gotham!" He gestured at the city around them, which was every bit the fine metropolis that the Gotham City that Clark knew wasn't.

"No, the city that I'm from. Metropolis. It's gone. It's like it never existed at all."

No glint of recognition.

"You mean on your planet, Krypton?" Robin asked. "Is that why you're here?"

"No, Krypton is long gone. Metropolis is supposed to be across the bay from Gotham. The headquarters of the Daily Planet, Lex Corp, the Metropolis Metros, it's all disappeared."

Finally, Bruce lowered the megaphone with a thoughtful frown. "I've never heard of a city named Metropolis, but this sounds serious."

"What do you mean you've never heard of Metropolis?" As quietly as he could, Clark whispered, "Bruce, can we talk somewhere privately?"

It was only barely loud enough for Robin to hear, but the boy reeled back in shock. "Holy flying blabbermouth, Batman!"

It sounded like a sign of some kind, but there was no answering activity, only looks of surprise from the assembled bystanders. Bruce seemed to be the most startled of them all, glancing wildly between Clark, Robin, and the crowd. He almost tossed aside the megaphone before abruptly raising it again.

"An excellent idea, Super-Man. A private lunch may give you some time to adapt to our ways. If you would care to follow us?" Bruce motioned toward a car waiting on the side of the road.

It was like a classic Cadillac convertible, in black with red highlights, wings on the back, and a small, red bat symbol painted on both sides. It wasn't only the exterior that had been custom-made; the car was lined with all manner of neatly labeled devices. The only things missing were turrets and a fully shielded cab.

Just as Bruce and Robin opened the doors, the bright red phone between the seats began to ring.

They exchanged a glance and Bruce sat down in the driver's seat to take the call. "What is it, Commissioner?"

A man's voice came from the other end, "It's Catwoman! She's up to her old tricks and you're the only one who can stop her."

"We're on our way."

Bruce put the phone back on the receiver.

"I'm sorry Super-Man, but our chat will have to wait; Gotham City needs its Caped Crusaders. Robin, be on your guard, that fiendish feline, Catwoman is on the prowl again," Bruce said with the utmost sincerity.

"Don't worry, Batman, we won't let her get away."

Batman and Robin piled into the car and sped off into the city. Clark rose into the air and followed after them. They wove through the city streets, obeying every traffic sign and never going above the speed limit. People stopped and stared, and one policeman even raised his hat as they passed.

"Is that the alien following the Batmobile?"

"Will there be more of them?"

"I wonder what Batman will do."

They finally pulled to a stop in front of a white marble building with a row of Grecian columns along the front, and a sign hung across them proclaiming it to be the Gotham City Art Museum.

Batman and Robin ran inside, dodging past oblivious museum-goers as they barreled to the stairs. The lead in the walls wasn't enough to block Clark's x-ray vision. In a quiet, but not empty, gallery at the top of the stairs, a woman in a black catsuit, wearing a pair of cat ears like part of a Halloween costume, already had a hand on a precious, little cat statuette, committing burglary in broad daylight. Clark hovered outside the window, but this was Gotham City, and it was a job for Batman, not Superman.

Batman and Robin burst into the gallery just as Catwoman stepped up onto the windowsill to make her getaway by the waiting fire escape. A batarang followed, embedding itself in the wall just beside her, but far enough away there was no risk of even drawing blood.

"Give it up now! You're outnumbered," Robin shouted.

"This cat isn't going back in the bag that easily," Catwoman purred.

Bruce readied another batarang, but he didn't throw it. "Put down the statue, Catwoman, and no one gets hurt."

It was futile, of course, but Clark was surprised by the gesture of mercy. This was a new side of Batman.

Catwoman only laughed. "Nice try, Batman!" She lashed out her wip at the same moment as he drew his batarang, knocking it from his hand.

"She's getting away!" Robin cried after her as she flipped out the window.

Batman and Robin didn't have a chance to pursue, as the respectable men who had seemed so preoccupied with the paintings on the walls that they didn't even notice the burglary in their midst, suddenly turned on them, brandishing batons. Underneath their suit jackets, they were all wearing brightly colored sweaters with "GOON" printed on the front.

They charged at Batman and Robin from all sides, but this was not Superman's place to intervene, and he should have known there wouldn't be too much of a fight against Gotham's Dark Knight. They got a few hits in, but with a punch, and a kick, and a throw, each of the goons was tossed harmlessly aside.

Just as Bruce knocked aside the last goon, a man in a bright green spandex, with a large question mark on his chest, came bursting through the door carrying a gun the size of a rocket launcher, aimed at Bruce. His finger pressed on the trigger, but Clark moved even faster than the speed of thought.

In an instant, Clark hovered in front of Bruce and the oversized bullet shattered harmlessly against his chest, splattering his costume in bright red.

"The Riddler!" Robin exclaimed. "But I thought this was Catwoman's case to crack."

The man gave a wild, giggling laugh and jumped, doubled over in laughter, so his knees nearly touched his chest. "And leave all the fun to her? Not this time! And thanks to your new friend from outer space, you're one clue short, Batman and the Boy Blunder!"

"Wait, Riddler, you'd run away without even leaving a hint?" Bruce attempted, even as Riddler's goons got back on their feet.

The Riddler only burst into another fit of laughter. "You'll see soon enough, Batman! Come on, men, we have bigger plans!"

Robin readied for a fight, but Bruce motioned him back as the Riddler pranced off, surrounded by his goons.

"What now, Batman?" the boy said. "We don't even have one of the Riddler's cryptic clues thanks to our extraterrestrial friend."

"It's all right, Robin," Bruce said, a hand on Robin's shoulder. He turned to Clark. "Thank you, Super-Man, it's not every day that someone jumps in front of a bullet for me, even a paint bullet. It seems like we have a lot to talk about, if you'll follow Robin and I back to our secret crime-fighting headquarters."

"The Batcave?" Clark said.

"Gosh! Is there anything you don't know about us?" Robin exclaimed.

Clark followed the Batmobile as it wove back along city streets. People stopped to stare as they passed. However, the crowds soon faded as they left the heart of the city, with its storefronts and low skyscrapers, and wound past the suburbs, into the surrounding yellow, grassy hills, scattered with scrub brush and the occasional gnarled tree.

Fourteen miles out of Gotham City, the narrow, dusty road turned along a rocky cliff-face. Above, just out of human sight, was stately Wayne Manor, and carved into the cliffs directly beneath it was the cavernous headquarters of Batman and Robin.

Just outside the cave, there was a sudden profusion of greenery at the foot of the cliff, extending up onto the rocks in climbing tendrils that half-covered the entrance. The dirt road forked, leading directly into the cliff, blocked by a meager wooden barricade, painted with red and white warning stripes, as if for a construction site.

The Batmobile turned and skidded onto the fork, sending up a cloud of dust in its wake, and the barrier folded back to let the car pass over it, into a long, roughly hewn, but well-lit tunnel leading down into the cave. Clark followed after them, into a small cavern built into the rock. There were no other chambers leading off of it, only a shaft up to the manor.

The car pulled to a stop on a small pad in the center, only big enough for one vehicle. The rest of the space was filled with blocky metal consoles displaying indecipherable patterns of flashing lights, all presumably powered by an immense cylinder that took up the back of the cave, supported on all sides by angled metal columns. Each device was meticulously labeled with a large sign, for whose benefit, Clark didn't know.

Bruce and Robin climbed out of the car and Clark descended to meet them.

Bruce still looked calm, but he stood firm to confront the Man of Steel. "Super-Man, thank you for your assistance. It's my hope that Robin and I can return the favor, however, if you're going to be staying on Earth, there are things you should know. I don't know how you have learned my name, but I must tell you that here, those who fight for justice must sometimes draw a veil of secrecy between their ordinary lives and their crusade. The world does not know that Batman is Bruce Wayne or that Robin is Dick Grayson."

That was not what Clark had been hoping for. "I know. You don't recognize me at all?"

Bruce betrayed no more recognition than his young companion. "I'm afraid I haven't had the pleasure, and I wouldn't forget meeting someone like you, unless there's been a memory wiping incident I'm not recalling."

"I don't remember one either," Robin said.

"But we wouldn't." Bruce seemed, remarkably, to take the prospect in stride.

"Gosh, what a puzzler!"

Clark interrupted their speculation, "No, Bruce, we must not have met yet. It's a pleasure to finally meet you, Robin. You both must have been sent back in time too, or transported wherever this really is, just from earlier. Do you remember how it happened?"

Again, Bruce seemed uncertain. "I won't say it's impossible, as very few things truly are. But I confess, I have no memory of living anywhere but Gotham City, or in any time other than my own."

Bruce turned to Robin, who agreed, "Me neither, Batman! It's a pretty wild idea."

"A wild idea indeed…" Bruce crossed his arms over his chest and began to pace between the blinking machines.

Clark wasn't sure where to begin to try to figure out what it all meant: could it be memory loss, as Bruce had suggested, or something even more dire?

"And how does that missing Metropolis fit into it?" Robin put in. "Cities don't just disappear!"

"... Unless they never existed at all! You've done it, Robin!"

"But Batman, even all our archnemeses working together couldn't fabricate a whole city."

"No, they wouldn't need to if my hunch is right. Super-Man, will you permit me?" Bruce motioned toward a console conveniently labeled as a "Dimensional Bat-Scanner."

Clark obliged.

"It will just take a few measurements."

Bruce gently pressed a pair of electrodes onto Clark's forehead, one onto his neck, and another at his wrist, all connected back to the machine by colorful wires. Then, Bruce returned to the console. It gave a series of beeps and whistles as he pressed buttons and turned switches, and finally activated it with the pull of a large lever with "Start" written on the handle in big letters.

Lights flashed and the machine beeped even more vigorously. Something began to churn within, and a strip of paper began to feed out of a slot in the top bearing indecipherable readings. Bruce tore it off and examined them, apparently able to glean more than Clark could.

"It's just as I suspected!" Bruce exclaimed.

"What is it?" Robin asked, trying to read over his shoulder.

"Super-Man's body is accustomed to a slightly different vibrational frequency. You must have come here from another dimension."

"Holy quantum mechanics, Batman! But then how does Super-Man know you?"

"There must be another version of Batman and Robin in Super-Man's dimension." Bruce glanced at Clark for confirmation.

Clark nodded. It sounded absurd, but it would have explained it.

"But if we're us, but they're also us, then who are we?" Robin seemed to only get increasingly lost the deeper he went.

However, Bruce nodded sagely. "A very important question, Robin, to which we may never truly know the answer."

Clark finally spoke up, "There is a Batman in my dimension, but then why is there no Superman or Metropolis in this dimension?"

"Maybe our Super-Man is still on the planet Krypton," Robin suggested. "But I don't know how that would account for a whole city being missing, unless it only exists because of you."

"Metropolis was around long before I landed on Earth."

Before they could make any more headway, the heroes were joined by an older man in a black suit and tie, with heavy glasses. "Pardon me, Master Super-Man. Master Batman, should I notify your lunch engagement that you are otherwise occupied?"

It was Alfred, but more prim and proper than Clark had ever seen Bruce's weary caretaker.

"Oh gee!" Robin exclaimed. "I forgot we were going to have lunch with Aunt Harriet! She must be wondering where we are."

"It wouldn't be the first time," Bruce said with a smile at his ward. "No, Alfred, tell Aunt Harriet we just called and will be there shortly. Super-Man, I don't know what it's like in your dimension, but here, Dick's Aunt Harriet is as unaware of our secret identities as the rest of the world. You'll need some civilian clothes to blend in; Alfred should be able to supply you with some of mine."

"Thank you, Bruce."

To Clark's surprise, Bruce smiled and held out a hand to him. "It's been a pleasure to meet you, Super-Man."

Clark accepted Bruce's gloved hand. His grip was firm, but friendly, not competitive. "Likewise."