The aftermath of the particle accelerator explosion was pure chaos. Emergency services were overwhelmed by calls about people who'd been injured in the blast or by people who were taking advantage of the chaos and causing riots. Every hospital in the city was packed and every available doctor in the city was being called in to help and CCPD was being overwhelmed by the amount of emergency calls coming in, since just like in any crisis, the people seemed to go insane as rioting was breaking out.

Barry was currently trying to run around the city as fast as he could, trying to restore some measure of calm to the city, trying to help as many people as he could. But he was only one guy and he was still getting used to his speed and wasn't sure how fast he could go without losing control.

However, he didn't care about the risk as he just finished saving a whole family from their house collapsing.

In less than a second, he'd rescued a father, a mother and two kids who were around the same age he'd been when he'd lost his own mother and he'd be damned if he'd let any other kids go through that. For either of their parents.

But then he heard them shout about how their dog was still in there, but the house was on fire and it was getting too hot for him to go back in.

"Damn it." Barry said, only to see a quick blue blur that might even be faster than him swoop into the house and then, suddenly Supergirl came out, with a big lab in her arms, the dog licking her face as she landed and set the dog down.

"Rusty." one of the kids said as she rushed up to her dog and hugged the dog.

"Thank you Supergirl." the mom said and Supergirl smiled.

"My pleasure ma'am. Now if you'll excuse me, this city needs as much help as it can get right now." Supergirl said as she flew off, before she noticed a mysterious red blur racing through the streets of Central City.

And when she used her super vision to get a closer look at the blur and was shocked to see it was a man.

"Well, this just got interesting." Supergirl said, since she could tell that at least right now, whoever this man, he was trying to help, which meant that he was a good guy, but before she knew she shouldn't just assume that until after she got to know him better, which was why, since she was faster than him, she landed right in front of him.

Barry was shocked when Supergirl landed in front of him.

"Supergirl." Barry said, trying to contain his awe at meeting the world's newest superhero. At least until him.

"Who are you?" Supergirl asked him and Barry knew he had to come up with a superhero name quickly, since he wasn't telling his real name to a stranger, even the girl of steel.

"Call me the Flash." Barry said before he could think of anything else and he had to admit, he liked that name.

"Catchy. I saw you rescue that family from the house, though you did miss the dog." Supergirl said.

"It was too hot for me to go back in. If I could've gone in to save the dog, I would have, but you handled it." Flash said.

"You seem like you want to help, but how long have you had your powers for?" Supergirl asked.

"A few days. I only revealed myself now because my city needs help and I wasn't gonna let it be destroyed just because I'm still learning to control my speed." the Flash said.

"Which I can respect and it looks like you're trying to work within your limits. Your heart seems to be in the right place, but once things calm down, we need to talk. I need to make sure that you're not a threat. But for now, keep doing what you're doing and take this." Supergirl said as she handed him a watch.

"What's this?" Flash asked.

"It's a signal watch. You're still a rookie and you have a lot to learn and while I'm still relatively new to this myself, I've still been training to use my powers for years. If you feel like you're being overwhelmed, give it a tap and I'll come help." Supergirl said and Flash nodded, honestly grateful that she was giving him a direct line to her as they both returned to trying to help the city.

After spending what felt like hours restoring calm to the city, the Flash and Supergirl met up again on a rooftop outside Central City.

"Nice work for your first time out." Supergirl said and Flash smiled at her.

"Thank you. That means a lot coming from you. Though I did notice your cousin in the city too. Is he coming?" Flash asked.

"I don't know. He and I aren't exactly talking right beyond the job right now and this doesn't concern him." Supergirl said.

"Okay then." Flash said.

"Where did you get that suit, since while I'm surprised to see that it held up against your speed, it doesn't exactly look like it was designed for that." Supergirl asked.

"It's something that was originally meant to be used to replace the turnouts firefighters wear, just repurposed." Flash explained.

"Where did you get it?" Supergirl asked.

"Where did you get your suit?" Flash asked defensively.

"I made it myself, just like how Superman made his. Now, your turn, where did you get your suit from?" Supergirl asked, though she could guess.

"You already know, don't you?" Flash asked.

"I'm guessing it's a prototype from Star Labs. I'm guessing that you were working with them before the explosion, so they gave you that suit so that you could help clean up their mess." Supergirl said.

"That's one way to put it, but I doubt they'll be able to help me anymore, since I think we both know that they're going under after this mess. Considering how many people were killed or injured either by the initial blast or the rioting that came afterwards." Flash said.

"Probably, but there's always a chance that some help could come if you know where to look." Supergirl said.

"Still, it's a shame, because a lot of good people work or did work at Star Labs and it's not fair that they're reputations will likely be ruined because of their association with the company." Flash said.

"I agree with you on that. And for what it's worth, I think that it's good that you've decided to do what you're doing now, since I have a feeling that Central City is going to need a hero to protect it now more than ever." Supergirl said and Flash nodded, before he yawned, since unlike her, he needed to sleep.

"Go home, I don't think there's anything more that can be done for this city tonight." Supergirl said as she flew off.

"Cool." Flash said as he sped off.

"Cool." Supergirl said as she watched him race away through the streets.

I hope you guys liked the first crossover of this series. Not the one with the most action, but I was trying to mirror Barry and Oliver's meeting in the Flash series premiere, and yes, eventually Oliver will join the Trinity as well, when the right opportunity presents itself.