Author's Note: This story is my answer to all the angst currently happening on The Flash. To forewarn readers, this story contains spoilers for the entire season of Supergirl and everything that has happened so far on The Flash, although I've taken a few liberties with certain plotlines. This story reflects my hope for future Supergirl/Flash crossovers, and it should be wrapped up in two chapters. I know this won't happen in upcoming episodes of The Flash; this is just my take on one way things could've been done.

I do not own the rights to any characters from the DC Universe—I just enjoy borrowing them from time to time.

Now, thank you for reading!


Kara's life hadn't been easy lately.

Her boss, Cat Grant, had upgraded her job. She was no longer Cat's assistant; instead, Kara had control over what she did each day. In some ways, it was liberating, but in others, it was overwhelming. She now had employees to manage, and she had to meet not just Cat's expectations, but also the expectations of other department heads within Catco Worldwide Media.

Kara found that she enjoyed the challenge, though. Her day job kept her busy and prevented her from thinking about the darker aspects of her life.

She'd lost her aunt Astra recently, and she'd been forced to do battle with Astra's husband Non when he'd become hell-bent on destroying all the people of Earth. It wasn't an easy fight; in fact, Kara had thought she wouldn't survive it. But with help from her foster sister Alex Danvers and her Martian ally J'onn J'onzz, Kara had managed to pull through.

After that fight, Kara had thought her life might calm down, but she was wrong about that. She and Alex had found out that Jeremiah Danvers—Alex's father and Kara's foster father—might be alive, but weeks later, they were still no closer to discovering his location. All they knew was that an organization called Cadmus was behind his disappearance, but Cadmus was apparently very skilled at covering its tracks. There were no clear signs as to who operated the organization or where they might be holding Jeremiah.

On top of that—and her daily efforts to save people as her super-powered alter ego Supergirl—Kara was also dealing with the abrupt end of her latest relationship.

James Olsen was a great guy. He was kind and funny and smart, and he was an excellent resource to Kara whenever she faced new trials as Supergirl. And he'd even admitted that he loved Kara. The only problem was that he loved someone else more.

When they'd first started dating, Kara couldn't help but notice how James would still look to his former girlfriend Lucy Lane, whenever trouble arose. That habit continued throughout numerous crises, as did James and Lucy's innate ability to finish each other's sentences and predict each other's needs. Kara knew that they had been a couple for a long time before their breakup, but she couldn't ignore how well James and Lucy complemented each other.

Finally, Kara had reached a point where she needed to talk to James about the issue—and whether he really wanted to be apart from Lucy. In response, James had told Kara that he did love her, but that he loved Lucy too. He wished that he didn't have to make a choice, but he knew that it wasn't fair to anyone involved to let things continue the way they were.

In the end, he wanted to be with Lucy.

According to James, Lucy needed him in a way that Kara never would. And he couldn't handle always being second in his relationship with Kara. James told her that she placed her responsibilities as Supergirl ahead of him. He didn't want her to change that—the work that she did as Supergirl was important. But he wanted to be with someone with whom he could have an equal relationship.

Kara understood—of course she did. She'd dealt with relationship problems like this for nearly her entire time on Earth. She'd just hoped that things with James would be different—that maybe this time she could've shared every part of her life with someone.

But that someone wasn't going to be James Olsen.

As Kara suited up for her nightly patrol, she thought about her options. Her best friend Winn had said that he loved her, but his friendship was too important to her. Everything had become so awkward between them when Winn had tried to kiss her, and she couldn't let that happen again. She needed her friendship with Winn more than she needed a new boyfriend.

She could try to meet someone new, but there was no guarantee that things wouldn't end the same way they had with James. As she flew around National City, Kara wondered if she were better off on her own. Who could understand what the life of a superhero was really like? Who would be willing to put up with the sacrifices she might have to make?

Kara's mind then turned to Barry Allen—or as he was known in an alternate universe, the Flash.

He was the fastest man alive, and he'd understood many of the difficulties she was facing the last time he'd visited her Earth.

And that was the one problem with Barry Allen—he didn't exist on her world, and Kara didn't know how to cross the barrier between universes to find him. If Barry were here, Kara's choice would be simple. She would want to spend her time with Barry—the man who thought it was cool that she was an alien, the man who could keep up with her in every way, and the man who knew what it was like to be different in a world filled with normal people.

Kara tried to push those thoughts to the back of her mind, though. She knew it was pointless to dwell on Barry when she had no way of ever reaching him.

And suddenly she had something new to focus on—a woman's scream on the other side of town.

Kara concentrated on the woman's voice as she flew towards it.

"No! You can't do this!" the woman yelled desperately.

"Yes, I can," an eerie, distorted voice replied. "I will do whatever it takes to conquer this world—and any other that I go to."

Kara could now see the owners of the voices. They were standing in a park not far from Catco. The woman was a brunette who was close to Kara's height, and her arm was being held by the other speaker—a masked man dressed head-to-toe in black. The dark figure was a head taller than the woman, and there was a creepy, intense aura about him.

Kara didn't know who this guy was, but it was clear just by hearing him that he was bad news. She needed to remove the woman from harm's way, and then she would deal with the mysterious figure.

Flying at super-speed, Kara swooped in, pulled the woman away from the man, and brought her about a block away.

"Don't worry. You'll be safe here," Kara told her.

"No, I won't," the woman replied nervously, as she focused on something behind Kara.

Kara looked at the woman with furrowed brows before turning around to see what was drawing her attention. She was stunned to see the figure only a few feet away from her.

"Who are you?" Kara demanded. "How did you move that fast?"

"I was about to ask you the same thing," the man replied in his distorted tone.

"I'm Supergirl," Kara answered. "And I don't play games. I heard your threat against this world, and I'm not going to let you carry it out."

"How do you plan to stop me, little girl?" he said menacingly. In an instant, the masked man disappeared and then reappeared right in front of Kara—this time once again holding the woman's arm.

"Any way I have to," Kara said, before moving as quickly as she could. She pulled the woman away from the man and punched him as she went by.

The man was knocked back, but all too soon, he was standing right in front of her again.

"I'm impressed," he said. "You don't seem to have the speed-force, but you're still close to keeping up. I wonder what your speed would taste like." His statement was clearly a threat, and Kara felt a chill go down her spine at his words.

She was also bothered by the fact that he had used the term 'speed-force.' It wasn't a phrase commonly used on this Earth. In fact, the only other time Kara had heard speed-force was during Barry's last visit. It was the term Barry had used to describe his remarkable speed, and this man definitely moved like Barry—but not in a good way.

"What do you know about the speed-force?" Kara asked, hoping to gain some insight into this villain and how she could possibly stop him.

"What do you know about it, little girl?" the man questioned venomously. "Did the Flash tell you about it?"

Kara felt her heart pounding in her chest at the last question. This guy knew about the Flash and the speed-force. She worried whether this man might be some enemy of Barry's, and she hoped that Barry was okay right now. Her thoughts were interrupted, though, as the man continued to speak.

"The Flash has been to this world," he said. "I saw the trail he left behind between his Earth and this one. I thought I might cause a bit of damage here before heading back to his Earth and letting the Flash know about the destruction that's all his fault."

"You're the one making threats here, not the Flash," Kara replied forcefully. "If you try anything, you'll be the only one to blame. But it won't even come to that—I'll stop you before you can hurt anyone."

"How do you plan to stop me if you're the one I'm going to hurt?" the man asked before speeding closer to Kara. Suddenly, she felt a terrible, blinding pain near her heart. From what she could see, the man had somehow stuck his hand in her chest.

She soon dropped to the ground from the pain, and everything became fuzzy to Kara—as if she were on the brink of passing out. She could hear the woman screaming again, but there was nothing Kara could do to help her. She felt immobilized.

And then the dark figure was hovering over her.

"The Flash knows you, doesn't he, little girl? A heroic, good person like you—you're just his type. And Barry's how you know about the speed-force, isn't he?" the figure asked before reaching down and tearing her family symbol off her chest. "I've taken his speed from him, and now I've taken you. It will break him when I give him this, won't it?"

Kara wanted to put up a fight. She wanted to stop this lunatic, but she couldn't move. She needed to heal from whatever this guy had done to her, but she knew she didn't have time to waste with a villain like this on the loose.

The man grabbed the woman and pulled her toward him. "Time to go back to your Earth, Caitlin," he said before running them toward the middle of the field.

That was when Kara saw it—a strange blue light in the direction that the man was headed. Looking more closely at it, Kara thought she could see a tunnel within the light. It reminded her of the breach that Barry had crossed to return to his Earth, and Kara knew what she needed to do.

She saw the other speedster run into the breach, dragging the woman with him. He was trouble, and it was obvious that he didn't like Barry. He'd even said he'd taken the Flash's speed.

From what she'd just heard and witnessed, Kara knew that Barry needed her help, and she wasn't going to let her friend down. Mustering what she could of her strength, she stood up and then flew at the breach at her top speed.

Once inside the portal, Kara was confronted with a sensory overload. She could see and hear so many other worlds that she almost didn't know if she could go on, but somehow, she managed to continue. The man had said that he'd followed a trail Barry had left behind, leading to her Earth. Now all she needed to do was find the same path and go toward Barry's Earth.

It took a few moments, but eventually Kara discerned the tracks that Barry—as well as this mystery villain—had left heading toward the other Earth. Kara flew toward the breach and soon found herself on another Earth.

Once she was back on solid ground, Kara's knees gave out on her. She was still reeling from the attack she'd survived, and travelling across reality barriers wasn't as easy as Barry had made it seem.

Barry—the thought of him made Kara stand up again. She needed to find her friend and make sure that villain didn't hurt him. She thought back to everything that Barry had told her. He was a hero in Central City on this Earth. He worked for the police department, and he spent his spare time in a place called STAR Labs, hunting down bad guys.

Kara needed to start with Central City. That city existed on her Earth, so she knew where it was, but there wasn't a STAR Labs on her Earth, nor did she know which precinct Barry worked for. She was going to have to do some searching if she was going to find her friend.


Barry was beyond frustrated.

It felt like his life was falling apart, and his efforts so far to fix everything had ended in failure.

He was no longer the Flash. He'd lost his speed to Zoom after the villain had kidnapped his foster father's son. Barry couldn't sit by and let an innocent be killed, so he'd let Zoom take his speed, and now Barry felt helpless.

Sure, he was trying everything he could to regain his speed, but he and Earth 2's genius Harrison Wells had yet to successfully recreate the conditions that had given Barry his powers in the first place.

On top of that, Zoom had kidnapped Caitlin Snow—one of Barry's best friends and a brilliant scientist. With her help, they might've been able to restore Barry's abilities already, but without her, they were still fumbling through theories.

And just because the Flash was gone, it didn't stop bizarre, super-powered villains from showing up in Central City. Barry's ribcage was still seriously injured from his last encounter with a super-strong meta-human who'd turned evil, and Barry wondered how well he would do against the next bad guy who came to town.

He knew that he and his team would have to solve these problems on their own, though. His friends in Star City had their hands full with Damien Darkh, and Barry didn't have anyone else on this Earth that he could turn to—especially not anyone who could face off against meta-humans.

In that moment, Barry wished that Supergirl existed on his world. He didn't want her to have to deal with this mess, but he knew that if he'd needed her, she would've been here to help him, no matter how desperate the situation had become. She was incredible. She was good and strong and smart, and Barry wished that he'd had more time with her.

But she was interested in James Olsen—a guy who lived on her Earth, which had to make dating easier for them. Barry wasn't about to interfere in Supergirl's love life, especially when he didn't have a chance with her from a world away. But that didn't stop a guy from dreaming.

One day—if Barry ever had his powers back and he'd managed to defeat Zoom, he intended to go back to her Earth. He wanted to see Kara again, even if he could only be her friend.

For now, though, he needed to focus on regaining his abilities.

"Let's try it again, Harry," he said to Dr. Wells, as they worked on a makeshift particle accelerator.

This was attempt number 15. Something had gone wrong on each of the previous tries, but Barry knew they couldn't give up—not with Caitlin still in danger and Zoom still on the loose.

Dr. Wells and Barry's friend Cisco hooked up the last of the wiring. Once they were done, they stepped back to the control panel, and Cisco checked the calibrations. Barry's friend was a skilled engineer—and he also happened to be a meta-human, with helpful visions as well as the ability to open portals between different realities.

Barry hadn't told Cisco about visiting Kara's world yet. With the threat of Zoom overshadowing their lives, Barry didn't know how to tell his friends about the amazing adventure he'd had with an alien from another reality. Besides, he'd enjoyed having the private memories to retreat into when things became too bleak on his own Earth. The thought of sharing Kara with everyone else made Barry worry that he would lose something from his time with her.

It was foolish, but Barry couldn't help but keep Kara to himself.

When the calibrations were set, Dr. Wells flipped the switch. For a moment, it seemed like the device might be working, but all too soon, it began to spark, and some of the wiring caught on fire. Cisco ran towards the machine with a fire extinguisher, putting out the flames, and Barry looked down, sighing in frustration.

His hands balled into fists, as the feeling of failure returned to him. Barry needed to beat Zoom, and to do that, he needed his speed. He just didn't know what it was going to take to become the Flash again.

"What else do we have to do, Harry?" Barry questioned.

"We could increase the current levels that are being aimed directly at you once you're in the device," Dr. Wells answered, pointing to the place on the machine where Barry was going to have to stand once they'd worked out the kinks. "That would help prevent the rest of the circuitry from overloading."

"But?" Barry asked, knowing that there had to be a reason why Dr. Wells hadn't suggested this on a prior attempt.

"But if your super-healing doesn't automatically kick into effect—or even if it does, but it's just too weak, then the currents being directed at you could very well kill you," the scientist explained bluntly.

"But if I get my speed back too, maybe I'll be fast enough to run out of the machine before I'm dead," Barry replied.

"That's a big if, Barry," Dr. Wells said.

"What other choice do we have?" Barry asked, knowing that they were running low on options.

"Things are slow around here, aren't they?" a threatening voice said from behind them, and Barry knew instantly who it was.

He turned around and saw that Zoom was standing in their lab.

"What do you want?" Barry demanded.

"I wanted to give you a gift before I destroy this world," Zoom replied, before tossing a thick piece of fabric at him. "And I want you to know that I'm not going to stop with this world. I've already begun my reign of terror on other Earths, and your friends are already paying the price for it."

Barry looked down at the fabric. He knew the shape was familiar, and when he flipped it over, he felt like he was going to be sick.

He dropped to his knees and managed to voice the word, "No."

"Yes, Flash," Zoom began, mockingly calling him by his superhero name. "I hope you enjoy watching your world burn as much as I enjoyed killing your friend."

Zoom then sped away, leaving Barry feeling broken on the floor. She can't be dead, he thought. Kara was nearly invincible. Sure, he'd seen Livewire and Silver Banshee give her a beating, but she always recovered. She was the strongest person he knew.

"She can't be dead," he said aloud.

"What is it?" Cisco asked frantically. "Is it Caitlin?" He was clearly worried about their teammate, but Barry knew who'd really been hurt by Zoom.

"Barry, talk to me, man," Cisco said, as he went around the control panel for a closer look at what Zoom had thrown at him.

Barry knew that the symbol wouldn't mean anything to Cisco, though. Supergirl didn't exist on this world.

Cisco easily pulled the symbol out of Barry's hands, which seemed numb from the shock he was experiencing.

"Whoa," Cisco said, once he came in contact with the fabric. He took a step back and kept his eyes closed, as if he were having one of his visions.

"What is it?" Barry asked, wondering if Cisco had seen something about Kara.

"I see a hot chick flying," Cisco replied.

"So she's okay?" Barry asked desperately, wanting to know that Kara was all right.

"She looks…I guess I'd say angry or at least determined about something," he answered. "But she looks very much alive."

"Good," Barry said, rising to his feet. The fact that Kara was still alive was all that mattered to him.

"But wait a second, Barry," Cisco began. "Who is this girl, and how do you know her?" he asked, apparently not satisfied with giving all the answers and not receiving any in return.

"She's a friend of mine…from another Earth," Barry replied.

"You met her on Earth 2?" Cisco asked, referring to the time that they had travelled to Zoom's reality.

"No," Barry answered. "I met her on another version of Earth."

"What?" Cisco exclaimed. "How many other interdimensional trips have you taken, Barry?"

"Besides my Earth 2 trips, I've only gone to one other Earth," Barry explained. "And it was on accident, and I managed to come back to the exact moment in which I'd left, so none of you even noticed I was gone."

"How much time did you spend on this other Earth?" Dr. Wells piped in.

"A few days," Barry replied.

"So long enough that your mark on that Earth would have been more prominent than on Earths you hadn't visited," Dr. Wells commented.

"Wait, so you're saying I led Zoom to her Earth?" Barry asked.

"Her Earth? Did you stay there long enough to become attached, Allen?" Dr. Wells questioned.

"I meant the other other-Earth—I don't know what you want to call it—Earth 3?" Barry said. "She's one of the main heroes on that world, and she helped me get back here—that's why I thought of it as her Earth, but sure, let's call it Earth 3. And now if we're done debating semantics, can we return to getting my speed back? Zoom's still out there, he still has Caitlin, and next time he might just succeed at killing one of my friends."

"Guys?" Iris' voice came in over the intercom.

"What?" Barry said, with more anger than he intended.

"I think you need to get up here," she said. "There's a new big bad in town."

Barry, Cisco, and Dr. Wells headed up to the control room at a pace that was far too slow for Barry's taste. He wanted his speed back more than he wanted anything right now.

"Take a look at this," Iris said to them once they'd reached the room. She was pointing to one of the large computer monitors that showed footage from a CCPD traffic camera.

A man was on the screen, wearing armor and carrying a rather vicious looking staff. He was walking along a plaza, where civilians seemed to be cowering in fear, and soon enough Barry understood the people's reaction. The man pointed his staff at a group of bystanders, and a beam of energy shot from it, blowing up the ground right in front them and knocking them all backwards.

Barry didn't know if the blast had killed the victims or just harmed them, but either way, he knew this guy had to be stopped.

"I have to get out there," Barry said.

"And do what, Barry?" Cisco asked. "You're still recovering from your last run-in with an evil meta-human. What do you think you can do against this guy?"

"I have to try something," he said, with frustration apparent in his voice. "We could turn on the particle accelerator device right now, and I'll just go for it. We'll stop these trials, and I'll just see if I can become the Flash again."

"That would be suicide right now, Allen," Dr. Wells said. "We don't have a way to make the machine work without killing you in the process."

"Then I'll just put on the suit and drive out there," Barry replied. "I'll at least give him another target to hit at other than innocent civilians."

"Hold up a second, Barry," Iris said, still watching the screens. Another monitor showed a reporter trying to cover the story.

"We have a new player on the scene," the reporter explained, gesturing behind her. The cameraman panned to the left, and Barry could once again see the new villain. But now he could also see someone standing in between the bad guy and the civilians—and that someone just happened to have blonde hair and was wearing a red cape.

"Kara," Barry whispered, as he felt true joy for the first time since losing his powers. She was alive, and not only that, she was also on his world.

Barry tried to push aside his feeling of elation when Kara started to fight the staff-wielder. He needed to focus on what was happening and make sure his friend was all right.

Kara knew what she was doing, though. She expertly managed to disarm the bad guy after several well-aimed punches. And after a few more moments, the man was unconscious, and Kara was holding his staff.

Barry took a good look at her. As Cisco had described, she seemed determined, but Barry already knew that when Kara set her mind to something, she didn't give up easily. Kara also looked a bit worn out. It wasn't obvious, but he knew what Kara looked like at full strength. And Barry could tell that she'd been through something recently. If Barry didn't pick that up from her face, he could've been able to tell it from the way her suit looked. There was only blue where her family symbol should be.

But all that really mattered to Barry was that she was alive—and he wanted her to stay that way.

The reporter seemed determined to have the full story on the situation. She ran up to Kara and shoved her microphone in his friend's face.

"You just stopped the latest madman to go on a rampage in Central City," the reporter began. "Who are you? Do you work with the Flash? Are you his replacement?"

The words hit Barry hard. People were losing faith in him. He hadn't been able to save a number of Central City residents who'd been in trouble since he'd lost his speed, and the public was clearly taking notice.

"I'm not the Flash's replacement," Kara replied firmly. "I'm a friend of his, and like him, I try to help people wherever I can. The Flash hasn't given up on Central City," she added. "Central City shouldn't give up on him."

Law enforcement arrived in the background, and as soon as Kara saw them, she sped over to them and handed off the staff. She then took to the skies, vanishing in an instant from the camera lens.

"Dude, your girlfriend is awesome," Cisco said.

"She's not my girlfriend," Barry corrected.

"Where do you think she's headed, Allen?" Dr. Wells questioned.

"I don't know," Barry replied. "STAR Labs didn't exist on her Earth. I told her about this place, but it's not like I drew a map for her of all the important places in my life. I don't know if she even realizes that she's on my Earth."

"We should try to find a way to get in contact with her," Dr. Wells said. "Zoom is here on this Earth. You don't have your speed, Allen, but your friend seems capable of handling herself in fight. If Zoom shows up again, we're going to need someone who can take him on."

"I don't want to endanger her," Barry said. "He tried to hurt her already—I don't want to risk anything happening to her."

"Think about it this way, Allen," Dr. Wells began. "If Zoom finds her on this Earth before we do, if he realizes he failed to kill her the last time he tried, do you think he's just going to let her go? Or do you think he's going to try to kill her again? She needs to know that she might be a target of Zoom's."

Barry couldn't disagree with Dr. Wells on that, and he had an idea on how he might be able to find her.

"Stay here," Barry told his friends. "I'll see what I can do."

He headed for the exit to the building. Once outside in the empty parking lot, he started yelling the one word he hoped Kara would hear.

"Supergirl!" he cried. "Supergirl!"

No one on this Earth knew her superhero name. There was a chance with her super-hearing that she might pick up on his yells.

Barry soon realized, though, that there was more than a chance that she heard him. In a matter of seconds, Kara had landed right in front of him with a look of relief on her face.

"Barry!" she exclaimed, before running up to him and hugging him tightly.

He winced at her grip, and she seemed to notice his reaction.

"I'm sorry," she said, pulling back from him. "I just thought the worst when that crazy guy showed up on my Earth earlier, and I've been so worried about you. I'm so glad to see you're okay."

"I was just thinking the exact same thing about you," Barry replied with a strained smile, as he tried to ignore the pain from his sides.

"But you're not okay," Kara said, again picking up on his injuries. She looked him up and down at that, and Barry knew she was scrutinizing him closely with her abilities. "Oh God, Barry! Two of your ribs are broken. I know I'm not feeling like myself at the moment, but I thought I had more control than that. Did I just do that to you?" she asked worriedly.

"No," Barry said, placing his hands on her upper arms, trying to reassure her. "I don't have my super-healing abilities right now, so I'm still recovering from my fight with a nasty meta-human last week," he explained.

"And you don't have your speed," Kara said—as a statement, not a question.

"It's that obvious that I'm slow now," he said.

"No, it's just what the creepy guy in black said," Kara replied. "He told me he took your speed."

"He did," Barry admitted, sounding defeated. "But I'm trying to get my speed back, and once I do, I'm going to stop him."

"I'm sure you will," she said.

"In the meantime, though, I wanted you to know that the guy—we call him Zoom—he's out there on this Earth, and he might try to hurt you," Barry said. "I want you to stay away from him."

"He already did try to hurt me, Barry," she said. "But I'm apparently not as killable as he thought."

Barry was relieved that he hadn't lost Kara to Zoom tonight, but he couldn't say he was comforted to hear her talk about how Zoom had tried to kill her.

"I'm sorry," he said to her, pulling his hands away. "I'm the reason Zoom went to your Earth. I'm the reason he attacked you. If he'd managed to…" Barry couldn't finish the thought.

"I'm okay, Barry," Kara said, placing her hand gently on Barry's cheek. "And you're okay. And we're going to find a way to beat this guy Zoom."

"Together?" he questioned, with a slight grin on his face.

"Together," she replied assertively. "Now tell me your plan."