Disclaimer- I do not own Steven Universe or Batman. All Characters from these two franchises are property of Cartoon Network and DC Comics. However, Emerald is an OC, and thus I have creative flexibility.

It was a perfectly lovely day on the coast of Beach City. The sun was shining, the birds were flying and chirping, and there wasn't a sign of trouble in the sky.

Near the coast lay an ancient structure. It was a coarse rock temple the size of a mountain. Having the build of a stone goddess with four arms, the formation was covered in moss and sheltered a tiny house in its remaining hands. To be an additional cherry on top, a tall lighthouse lay on the top of the mountain, acting as the stone temple's backbone.

Inside the house, the occupants - better known as the Crystal Gems - were enjoying a normal day. Pearl was fixing a small robot on the kitchen table, while Steven and Connie were watching TV from his bed up on the landing. Purple-skinned Amethyst lay on the sofa, a crumb of pizza on her chin.

"So...bored," Amethyst moaned in tiredness. She plucked a corner of her white tank top to satisfy herself.

"You know, Amethyst," Pearl said, "If you want to do something, you can help me by getting a capacitor for this robot." She motioned towards a piece of metal lying on the table in front of the sofa.

"Pass," Amethyst replied lazily.

Steven, intrigued by their conversation, turned away from looking at the television. "Pearl, where's Garnet?"

"Out looking for some old Gem tech, I'd expect," Pearl replied.

Satisfied, Steven turned back to the TV alongside Connie. They were watching an episode of Crying Breakfast Friends, where Spoon and Pear wound up in an alternate dimension. After meeting a human being, the three put their difference aside to stop a living pile of trash. The episode was odd, and he could tell she was getting that vibe.

"This is weird," Connie replied. "I think other episodes are better than this."

"I guess so," Steven said. "But don't you think-"

His speech was interrupted by a familiar opening of the door. Steven turned like everyone else to see the purple-skinned Garnet enter the room. Her black afro and multicolored specs were as familiar as ever. However, the troubled look planted on her face was not.

" Hey, Garnet. What's up?" Steven asked innocently.

"Trouble," she said in a solemn tone.

Steven, Connie, and the other looked at each other. This couldn't be good.

...

The whole gang sat around the living room, all looking to Garnet, who'd been explaining what she was so worried about.

"I went over to the Kindergarten because I wanted to see if there was any old Ruby ships, ones we could use to travel in space, if necessary. But when I got there, I saw something...off," she paused slightly.

"What was it?" Amethyst asked.

Garnet took a moment to compose herself before she could respond. "It was a Gem...from Homeworld."

"A Homeworld gem?" said Connie, shocked.

"What kind of gem was it?" Pearl asked.

"It was an Emerald," Garnet responded. The room soon filled with a wave of fear from the other Gems.

Steven, curious and nervous about the silence, asked "Pearl, what's an Emerald?"

"A rare and powerful Homeworld gem," she said. "They were an elite guard for White Diamond, but disappeared after our Resistance defeated her Pink counterpart. They're powerful, Steven - incredible strength and skills more precise than mine or Garnet's, and built-in blades that can cut through anything."

"So what?" Amethyst said. "We've taken on Jasper and tons of other bad guys. We can deal with one Emerald, right?"

"That's not the point, Amethyst. If an Emerald is here, it must mean that they're on Homeworld business, and probably looking for something...something likely dangerous. If so, we have to find and stop her before she finds whatever she's looking for," Garnet replied.

Connie raised a hand. "Yeah, but didn't you say she was at the Kindergarten?"

"She isn't anymore," said Garnet. "I saw her teleport out away before I could glean more. She could be anywhere on Earth."

Steven thought about this for a moment. And then something came to him.

"I know somebody who can find her!"

...

The Crystal Gems looked across the vast blue ocean facing their porch. It was a couple of hours after noon, and the shadows had shifted in accordance with the sun. They were waiting for a specific duo, one of the two having - hopefully - the knowledge they needed.

Suddenly a speck appeared in the distance and began to get larger. As it did, colors and shapes took form, allowing the group to see two individuals slowly approaching. One was a slender blue-skinned girl, aqua hair and dress to match. She had two wings made out of water that flapped constantly, allowing her to levitate above the ocean blue. The other character was a small green individual with a face looking like it had goggles on, and a triangular shape of yellow hair. She held onto the slightly larger person, eventually peering towards the gathered Gems.

"Hey clods!" she exclaimed excitedly. Even from a distance, Peridot's trademark phrase could be heard in a heartbeat.

Steven waved intently as Lapis settled Peridot down and retracted her wings into her back. "Hey, guys!"

Lapis smiled upon the comment. "What's up?"

"We've got a problem, and we need your help to solve it," Pearl stated.

Both looked at each other. "What kind of problem?" Peridot asked nervously.

"You remember the Emeralds?" Garnet asked.

"'Course I do," Peridot said. "They were the meanest, toughest gems to serve White Diamond. Why do you ask?"

"An Emerald is on Earth, and we don't know where she went, or what she's looking for."

"You think you might know what she'd be here for, Perri?" Amethyst asked.

Peridot held her hand up to her face, attempting to concentrate. Lapis loomed over her friend, and as if a lightbulb lit up, she realized the answer.

"There's only one place she could've gone. But you're not going to like what I have to say…"

...

The Warp Pad boomed in an explosion of light as the seven figures materialized on it. Once the glow disappeared, all that remained were the Gems. They'd teleported to what appeared to be a stone ruin, complete with ridged rocks and broken concrete structures. What made it appear special were the alien markings strung over the place.

Garnet looked at her green-skinned friend. "Peridot, what is this place?"

"It's an old Homeworld laboratory," said Peridot. "When I arrived on Earth to conduct my assessments of this planet, I collected a good amount of minerals and life samples and brought them to this station. Of course, the constant fights with you clods" - she put extra emphasis on her favorite word - "made me too busy to work on anything I got."

"If this is a lab, where is it?" Connie asked. "All I see is wrecked marble."

"It's underneath, of course," Peridot replied. She pointed to a door shaped like a triangle; unlike the rest of the area, it seemed physically untouched. As they moved closer, they could see a small square box that glowed with green energy.

"It requires my fingerprints to get in. Wait a sec." Peridot scooched closer to the door and immediately stood as tall as she could before touching the scanner with her hand. A few seconds later, it beeped and then turned red.

"Error. Incorrect signature," a voice from the door said.

"What?" Peridot got angry at this issue. "I'm a Peridot! I should have access to this hunk of junk!"

"Well, you have regenerated since then. Maybe it doesn't remember you," Lapis said thoughtfully.

"This still stinks!" Peridot shouted in anger.

Steven studied the door. It looked sturdy and experienced, but maybe…

"Garnet," he said. "You should try to break it. I bet your strength would do it."

"I'll try," Garnet replied. She readied her hands, morphing them into fists with stars on top. Then she aimed them at the door and let loose, the heavy hands colliding with the withered brick. To everyone's surprise, the door fell apart easily.

"Not that hard, I guess," Garnet said. "Come on."

The other gems tagged along behind her. The exposed hallway began to head downwards, a series of stairs forcing the group to move slowly and carefully. Shadows pressed against them, while symbolic shapes appeared on the walls. If it hadn't been this obvious before, these marks were direct confirmation of this being a Gem laboratory.

Soon, a green glow appeared at the bottom of the stairs. Garnet made a signal to be quiet before turning to continue descending. At the bottom, the group saw what the lab looked like. It was, for the majority, an open space. Filled across it was various pieces of cylindered tech that looked definitely not of Earth. However, a glance or two said these devices hadn't been used in a very long time, as evidenced by the cracks and dust apparent on them.

Steven turned away from the basic viewpoint and saw that farther along the green glow emanated. "Guys!" he whispered. "Over there!"

All of the gems could see it; a smaller chamber that was lit up. As they neared, they heard a female voice talking to herself. Once around the corner, the group saw the gem. She was tall, slightly over Garnet's height. She had green skin and long dark grass hair with gem braids at the bottom. Homeworld tattoos lined her face and arms. Finally, she wore a simple jumpsuit with shoulder armor of black color. Put together, her image was powerful and terrifying.

"Whoa," said Amethyst in shock. "THAT'S Emerald?"

"In the flesh," whispered Peridot. "Don't go easy on her - she's dangerous."

They watched as Emerald moved over to a small chest near the back of the chamber. She opened it and produced a tube with an unknown organic content. Steven wondered what exactly it was. The closest thing he could recall to it was the Gem mutants he'd fought with Connie. Then it came to him. Are they mutants, too?

"Everyone get ready," Garnet whispered toughly. She tensed to get composed for the fight, followed by the others in their own ways. Steven himself prepared by making his shield out of thin air once again.

"Emerald!" Garnet shouted as the group stepped into the Gem's line of sight. "What are you doing here?"

The Homeworld Gem turned towards her with a cold grin. "I've found what I need, Crystal Gems – the perfect way to expand upon our science. I was planning on getting back to Homeworld without a cinch, but taking you all down won't be a problem!" She threw the canister upon the ground before extending her arms. As she did, sharp blades materialized on her wrists. They were colored an even darker shade of green, and the very sight of them was threatening.

Emerald shot forward, pointing the blades at Garnet. The experienced Crystal Gem barely locked his fists with the blades before being thrown backward. Pearl struck with her spear, but Emerald swirled around and chucked her into the nearby wall as well. Landing with an oof, she became unconscious. Seeing this, Steven got all the more worried.

"If she can't beat her, then who can?" He asked himself, mainly in shock.

"Don't think like that!" cried Connie. She leaped into the air next to him and landed in front of Emerald, leveling her sword at the Gem. Emerald responded by swiping her twin blades, deadlocking with Connie's pink sword like toothpicks in tight-knit teeth. Giving the girl a dark smile, Emerald applied pressure to the deadlock, giving her enough momentum to pull her blades out and attempt a swipe at Connie. The girls athletics became handy as she dodged the blow, back flipped, and landed a few feet away with her sword still in her hands.

"It'll take more than that to stop us," Connie stated seriously. The villainess simply smirked at the comment.

"Like I care. To me, all you Gems are nothing more than a disgrace to our empire."

"Not true!" Amethyst yelled while running, producing her whip and thrashing the balls at her. The sharp edges of the spikes collided with Emerald's armor, leaving a small set of scratches. Upon seeing them, Emerald's face lit up with rage.

"You...you Crystal Gems will pay!" She screamed in fury. Her dark green wrist blades grew to an uncomfortable length in response to this.

"Yeah, rig- whoa!" Amethyst swiftly dodged a jab from Emerald's weapon. She swung her spiked whip around for another go, but the taller and intimidating Gem simply grabbed it and used it to swung her into a stone pillar. "Oofff!"

"Amethyst!" Steven cried in shock. He gripped his pink shield before flinging it Emerald. The projectile found its mark and collided directly with her head, knocking her temporarily to the ground. As this happened, Peridot raised her hands and strained a little. The small metal container easily floated over to her, landing on the ground in front of her feet.

Emerald massaged her head, then turned to glance venomously at the two. "Rose Quartz, you ruin everything!" She loathed.

"In case you haven't noticed, I'm Steven!" He said in response.

"Yeah!" Peridot said in agreement. "Take that, clod!" Raising her tiny arms, the green alien concentrated on a stray rod of metal stuck in the wall next to her. It flew out of the wall and then directly at Emerald. However, the villainous Gen was more than ready. She quickly sliced through the air, leaving several pieces of cut metal on the ground. Peridot gaped at her in shock, as did Steven.

"A poor effort," Emerald cackled. She braced to run at them when a loud shout from behind caught her attention.

"Emerald!" The Gem turned in time to get a massive gut punch from Garnet, clearly enraged and more powerful than ever. The blow sent her back several feet, but she managed to brush it off as if it was nothing. Garnet pressed forward, delivering a series of punches and kicks. "Whatever you're planning on doing, it ends here!"

The villain was so busy with Garnet that she didn't notice Pearl sneaking up on her. Taking a second to create her trident, Pearl leapt forward with her weapon outstretched. However, the sharp blade was caught, to the shock of her be Garnet, by one of Emerald's swords. The sharp noise only proved she could fight on two fronts.

"Trying to beat me behind my back?" She sneered. "How 'noble' of you."

"Try this on for size!" The three saw Connie vaulting towards them in the air, aiming her sword at the villain. Knowing she couldn't hold her off as well, Emerald pushed Pearl to the side and held up her left blade in time to clash with the girl's. Connie pushed valiantly, but the green-skinned Gem managed to stay her ground and ultimately direct her back with tremendous force. Steven watched in shock as his best friend slammed into a wall, a tinge of pain in her arm causing her sword to fall.

"Connie!" He shouted. The boy turned to Lapis, the whole time having been near the far-off door. "Lapis, do something!"

"Got it!" She said confidently. The blue girl raised an arm, mustering all the control she had before letting a devastating blast of water out. The hydrokinetic burst went directly towards Emerald, sending her crashing into the nearest wall, just like she had done to everyone else. Pearl and Garnet, no longer dealing with her fury, relaxed and stood at the warrior of a villain.

"Not so tough now," said Pearl snidely. Garnet gave her a reproachful glance.

"I wouldn't be so sure," She replied. One of her heavy fists pointed to Emerald's body, which while unconscious, was feebly stirring. Meanwhile, Steven walked over to the canister and held it in his hand. His eyes slowly scanned the contents, which looked like some sort of brown goo mixed with toothpaste.

"Wow! We beat one of those clods!" Peridot cheered as she moved closer to the others. Everyone except Steven was staring at the temporarily knocked out Emerald, tired but ready in case she got up again. As predicted, the villainess' eyes opened and she suddenly stood up, the fight seeming to have had no effect on her.

"You thought you could beat me?" Emerald cackled. "Think twice."

"Ugh...here we go again," Lapis complained while absentmindedly creating a ball of water. Garnet and the others prepped for another fight, even If it was futile.

"Guys?" Everyone turned to Steven. He held the container of mysterious substances in his hand, which for some reason for glowing. He looked worried. "What's happening?"

"Steven!" Connie yelled. "Get away from It!"

He barely had time to do this. The second he threw it into the air, something strange happened. The room itself seemed to change and swell before a blue portal appeared out of thin air. The swirling energy vortex suddenly began to suck the air out of the space as if it was a vacuum cleaner.

"Hold on!" Garnet yelled. The gems firmly planted their feet in an attempt to resist the pull of the portal, but the rest of the room began to be pulled instead. Portions of the stone columns and walls degraded, then were sucked in. Emerald did her best to hang onto the wall she was next to, but despite her best efforts, her body was lifted up and she floated quickly into the breach. "Nooo!" She screamed before disappearing in a flash.

"Garnet, what do we do?!" Pearl asked urgently, attempting to hold onto the pillar next to her arm. Dust was colliding in front of them before being sucked away.

"Hang on, that's what!" Their leader answered. Steven tried as hard as he could, but whatever was happening was trying to stop him from doing so. Suddenly, a crashing sound filled her ears. Looking up, he was alarmed to see the ceiling was coming down on them. There was no escape.

"Watch out!" Steven screamed, but he knew it was futile. As strong and hard to hurt as they were, the Gems - as well as him and Connie - were just human. They couldn't survive it. Was this the end? He had planned on doing so much more in life.

As the ceiling came inches of hitting the Gems, a strange sensation occurred. They all didn't feel crashing pain or blackness. It was a feeling of pure elation, and the group felt they were floating farther away.

They were going somewhere - just somewhere they didn't know.

And that's chapter one! So, if you guys read my fiction Potluck, this story is sort of a spiritual sucessor. Because Potluck left the door open to crossovers, stories like this can happen. I can promise Batman and The Gems crossing paths will be climactic and cool! Also, I can confirm his usual allies, his friends from Detective Comics, and several of his foes will appear in this. It's time to be excited!