DISCLAIMER: I OWN NOTHING. I DON'T OWN THE CHARACTERS, THE STORY, THE SHOW, OR ANYTHING ELSE. I DON'T OWN ANYTHING. CHARACTERS BELONG TO MARVEL AND DC RESPECTIVELY. ONE MORE TIME BECAUSE THIS DISCLAIMER IS IMPORTANT. I DO NOT OWN ANYTHING.

Arrowverse and Avengers Crossover

SUMMARY: The heroes of the arrowverse have gathered together once more. However, something goes wrong. After an explosion, they find themselves trapped on an unknown earth. Meanwhile, the avengers are still split in the aftermath of the Sokovia accords. But when some familiar readings are found by Tony, will everyone be able to set aside their differences in the face of an impending invasion. Or more simply the arrowverse meets the MCU.

This is set a couple of months after civil war. Bucky is in Wakanda and Natasha has joined the Rogue Avengers on the run. (In this fic Clint didn't take the deal with the gov. Only Scott did.) So I will refer to the MCU as earth 616 as shown in a spider-man far from home promo.
This is set after season 3 of the flash with a couple of MAJOR changes.
1) Barry and Iris decided to break it off because they are more siblings than lovers.
2) Barry never needed to go into the speed force.
3) Caitlin never left. She learned to accept the Killer Frost part of her and they now work together.
This is also set after season 5 of Arrow with another set of changes.
1) Nyssa and Oliver never married.
2) Felicity died on Lian Yu.
3) Diggle was severely injured and can no longer go out in the field.
4) Roy was pardoned (somehow. idk. maybe I can write a fic about that later.)
This probably takes place around the beginning of season 3 of Supergirl. But its a little vaguer.
1) Kara is no longer mopey about Mon-El.
2) Alex and Maggie have broken up. But they've been apart for like seven months now.
As for legends, I haven't seen season 3. Even though I have already started season 4. So I'm not entirely sure where in the timeline we are for legends. Ummm… Let's see.
1) Sara and Ava aren't together and haven't met because I really don't like the time bureau, so they aren't in this.
2) The legends never broke time. But they still are chasing aberrations.
3) Sara and Ray were visiting Star City to see family when this begins so that's why none of the other legends are mentioned.

So yeah. A lot of changes. They're probably not that important but this world is just what I want it to be. Anyways. Enjoy! This chapter is just the beginning with the arrowverse characters. The rogue avengers will be introduced next chapter. And the rest of the Avengers... sometime after that. Enjoy! Please R&R.

SEPTEMBER 29, 2016, 3:40 PM

CENTRAL CITY - EARTH 1

"This is the second time within a year," Barry said running around the city punching out aliens wherever they could find them.

"Yeah. As much as I love hanging out with you guys, maybe we should try to do it without an alien invasion," Kara said hovering above the fight.

"Focus," Oliver said shooting three arrows consecutively watching as they hit their mark and the aliens fell. "We need to find out why they're here. It can't be a coincidence that four tech companies have been robbed by 'weird monsters' since these guys have shown up."

"I don't know but I have a bad feeling about this," Sara said taking out four more baddies with her bow-staff. Suddenly she heard four shots being fired right behind her. Turning she saw Kara's cute sister run up behind her. An alien lying dead right behind her.

"I agree with Sara something feels off about this," Alex said as she and Sara resumed fighting.

"Well, I think this is totally awesome," Cisco said hitting another assailant with his powers.

"Of course you do," Said Killer Frost shooting ice at another villain.

"Can we please refrain from commenting on how cool aliens are until after we stop them from invading the planet?" Roy said shooting off another few arrows.

"Sure. But I mean come on. This is amazing," Ray responded zipping in between creatures at a small size.

"Beloved, do your friends always speak during battle?" Nyssa asked slaying down another alien.

"Pretty much," Sara responded amused.

The battle continued for hours. It was almost dusk as the last few aliens were taken down.

"I think that's the last of them," Barry said coming to a stop. He was exhausted. He hadn't eaten in hours and he'd been running around all day. His muscles burned with exertion.

"Good I'm about ready to drop dead," Cisco said panting. The heroes congregated together discussing the battle and what to do in its aftermath. That's when Kara heard a strange noise. It was extremely faint. Without her super hearing, she wasn't sure she'd have heard it at all. Focusing on the noise she tried to work out what it was.

"... Kara are you listening. Kara?" Barry asked noticing the Kryptonian's attention was elsewhere. Suddenly it occurred to Supergirl what the noise was. It sounded oddly like a ticking noise. Like a bomb.

"Everyone get dow…" Kara started before being interrupted by a large bang followed by darkness.

Consciousness slowly returned to Oliver. His head was killing him. Remembering his training, he kept his heart rate steady and his breathing slow. He didn't know where he was or how he got there, so it was better safe than sorry. Clearly, some of the other heroes didn't have the same training. While Oliver could tell that he, Nyssa, Sara, Alex, and Roy were all attempting to hide their awareness, Kara, Barry, Caitlin, Cisco, and Ray all groaned as they awakened.

"Where are we?" Barry asked looking around. Oliver sighed. If they were captured, their captors would surely know they were awake now.

"I don't know," Oliver responded quickly getting up. Instinctually, he reached for his bow and let out a silent sigh of relief as he felt it and his quiver still attached to his back.

"What happened?" Caitlin asked standing up. The white of her hair was gone replaced with the chestnut brown color. She looked around confused.

"The bomb. We must've been transported somewhere," Alex concluded looking at her surroundings.

"Well if we were transported somewhere than I can get us back," Cisco said standing up. He went to open a breach. A faint blue light sputtered out of Cisco's hand before closing. "That's weird," he noted. "I don't know what happened. Let me try again." Cisco again attempted to open a breach, but he was met with the same results. "It's not working," He grunted as he tried again. After another failure, he let out a resigned sigh. "Sorry guys. I think we're on another earth. One really far from ours. I can't breach us home with my powers."

"It's ok Cisco," Caitlin said patting him kindly on the back.

"Well, what do we do now?" Roy said looking around at the group. "We aren't exactly dressed to be flying under the radar."

"And we have no idea what the people here think of breachers," Sara added.

Oliver looked around at the group. Realizing he was the one taking charge he sighed.

"I think we should split up for now. Do our comms still work?" He asked.

"They seem to be functioning fine for now," Cisco said.

"Then here's what we do. Nyssa and I will look for a town. Somewhere we can get food and clothes and hopefully a place to stay. Everyone else stays here. Hidden. We are in an unfamiliar environment. We need to be cautious."

Everyone nodded in agreement.

"Come, Oliver," Nyssa said walking into the forest. "We must find somewhere before dawn. It will be much more difficult to stay hidden if we move in the daylight." Oliver nodded in agreement and followed.

The two quickly and stealthily made their way through the forest before coming upon a small city.

"This will be perfect," Oliver said surveying the area with his eyes.

"Agreed. It will be easy to blend in at a city," Nyssa replied.

Jumping over rooftops, the pair mentally memorized the city. The two quickly recognized the language all of the signs were in making a note to speak in Russian if they were talked to.

"We should find suitable garbs. These clothes will make us sure targets." Nyssa noted as she and Oliver stood on a rooftop.

"Yes. We need to find a store or something. That way we can change clothes."

Oliver scanned the city until he noticed two figures moving stealthily through the night. To anyone else, they would have been mere shadows. But the Arrow and the daughter of the demon were not easily avoided.

"We should follow them," Oliver said quietly to Nyssa.

"Are you sure that is wise? This is not our world. We do not know what is going on."

"On any world, I'm pretty sure that is not a good sign. We follow them, I guarantee they try something." Oliver replied stubbornly. Regardless of whose world this was, criminals were criminals. He couldn't let this go.

"Very well," Nyssa said as the two took off silently through the rooftops. They followed the dark-clad people until they stopped on top of a store. The people quietly broke in not setting off a single alarm. Oliver and Nyssa silently followed. Entering the store and quietly creeping behind them. The two people walked quickly down the hallway. They were clearly in some kind of rush. The archer and assassin followed quietly for a few seconds until the pair stopped. They looked at each other exchanging some silent conversation before one of them whirled around shooting a knife straight at Nyssa's hidden form.

Authors Note: What'd you guys think? I haven't written a crossover before, so this is a first. I'd love to hear suggestions and any ideas. I am editing the next chapter so that should be out sometime tomorrow. Until next time!