Note: So, final chapter. I definitely think this is the best of the three and I hope you all enjoy reading it as much as I have writing it. Big shout out to my Beta, CharmedMilliE – Karry Master, for helping me expand this story and making it what it is now; and for all her Karry Universe fics for continuously inspiring me for this particular story. I should also add that the 'footnotes' to this story will be uploaded in a few days explaining how this universe is formed and whatnot, so if you have any questions you want answered about 'SuperEarth', write them in the reviews and I'll be sure to answer them in the footnotes. Right. To business!

Disclaimer: Read chapter two's disclaimer… ;-)

Chapter Three – Worlds Finest, Take Two.

"Who are you?" Jeremiah Danvers stood in front of Wells' revamped holding cell in the pipeline, his biological daughter by his side as they both glared at Zoom. Unlike Barry he hadn't removed his mask but had made several as-yet unsuccessful attempts at escaping his temporary prison, hitting the various walls and seeming to vibrate himself beyond the realms of vision to get out.

"What are you?" Zoom hadn't replied. Having failed to get out he now just stood, staring intimidatingly – albeit despite they not being able to see his face – at the DEO head. He's remained silent however. Most likely calculating when, or how, he could get out of his confinements. It had obviously been a long time since he was in such situation, it seemed.

"Why are you here?!" Jeremiah almost shouted this, frustrated at getting nowhere. He had never had this much problem with a prisoner before. Even Astra had been more talkative when they had her.

Ever since Kara had delivered the partially defrosting block of ice containing the speedster, Jeremiah and Alex had remained in his presence, watching him, trying to keep him in check, studying him, almost. As best as they could of course. Kara, meanwhile, had vanished with the unconscious body of Barry to Wells' lab.

"Why. Are. You. Here?" Alex now repeated her father, almost growling through her teeth and Zoom finally turned his attention to her; progress it seemed.

"Trapped," he finally growled, a single-word answer.

"Trapped? Here?" Jeremiah spoke up. "Is that why you needed the Flash?"

"Flash is not of this world," another simple reply, albeit on-point.

"Neither are you. Were you trying to use him to get back to your world? To his world?" Alex spoke before her father could.

"I need Flash. I need speed!" At this, Zoom hit the glass of his cell and Alex could have sworn one of his fingers passed through the solid substance. She hoped not, after all, Barry had said he could phase through walls.

-SuperFlash-

Barry had been stripped of his outfit, lying under a sheet on a make-shift hospital bed in Wells' lab – the very same room Caitlin had had Barry unconscious in a few times on Earth-1 – with Cisco Ramone and Kara looking down at his sleeping form.

"What did Zoom do to him?" Kara asked, a quiver in her voice.

"It's hard to tell," Cisco was the one to answer, "but he heals at superior speed. There are fractures all over his body, which look years old but could have been made in the last few months to a year. His back too. I guess it's not an easy life being the Flash…"

"Well, unlike Miss Danvers here, Mr Allen can break," Wells pointed out, moving over to the pair and Barry with a syringe. "Whatever happened to him allowed him the ability to recover quickly to fight another day, but I suspect whatever Zoom did, if it wasn't for your intervention 'Supergirl', we may indeed have a corpse on this bed than an unconscious young man."

As he spoke, Wells took a sample of Barry's blood. Kara looked to the small syringe with curiosity but didn't verbally question the professor as he moved back to his instruments. "Let's just hope he awakens soon as I doubt mine or Mr Ramone's updating on Zoom's personal cell will last."

"Zoom…" Barry groaned from the bed, turning his head on the pillow.

"Barry?" Kara asked tentatively, she reached for his hand under the sheet.

"Zoom!" Barry sat up, Kara withdrawing her hand quickly as he looked around in desperation. "Doctor Wells? Cisco? What…?" Barry's eyes fell on Kara and it seemed things slotted back into his mind as he reached for his head with both hands, cupping his forehead and groaning. "Please tell me he didn't get away?" He asked to the sheet now just covering his legs.

"We got him," Kara responded instantly. "He… did something to you but we managed to get him locked up, temporarily anyway."

Barry removed his hands to look at Kara. "Temporarily?"

"It won't take your Zoom friend long to find the right frequency to vibrate out of his containment and most likely come for you, Mr Allen." Wells returned to the bed's side, his bedside manner the same as his parallel self from Earths 1 and 2 – non-existent.

"He's not my friend" Barry pointed out, although not looking to Wells as he continued to stare, almost intently, at Kara, who blushed and looked at Wells herself.

"But we have some time to get actual answers from yourself, Barry," Wells added, forcing Barry to look from Kara to Harry, an eyebrow raised as he simply nodded, wanting to get Harry's questions over with. "Such as," Harry moved slightly closer, Cisco moving back instinctively, "how you came to be the Flash and why Zoom is after you."

Barry sighed. From the moment he'd landed in this strange DEO/STAR Labs merger he'd known he'd be asked this question, and he had his answers ready without really knowing it. "On my earth, when you turned on your Particle Accelerator it went wrong, malfunctioning during its public unveiling and bathed the city, Central City, in an unknown form of radiation during a severe and freak thunderstorm; I was struck by lightning and as a result gained my speed – it affected others in the city though, hundreds, if not thousands of civilians gaining super-powers from whatever elements surrounded them. We call them meta-humans."

"Is that what happened to Zoom?" Cisco breathed from Harry's side.

"Similar. On another Earth, a parallel Earth. Only he wasn't happy with what he was given. He wanted to go faster, but didn't want to work for it in the way I have; by training and pushing myself to go faster. He simply doesn't care who he hurts in his goal for ultimate speed, though."

"And that's why he wants you," Wells concluded, "to gain your speed?"

"Yeah," Barry looked down from Wells to the floor. "I think he's been breaching universes to find other Flashes to steal their speed. It's how he found me and how he killed… killed another Flash." He didn't want to say Jay's name. He still wasn't sure if Zoom was the same Jay he'd known. Zoom had debated this identity when confronted in the park earlier, but Cisco had vibed off Jay's helmet to Zoom. That meant something, didn't it?

"You've got to go back" it wasn't a question, but there was sadness in Kara's tone as Barry now looked to her again, "to your Earth. With him." She didn't know why she was sad. She knew this was coming, but deep down she didn't want it.

"Yeah," Barry nodded, feeling strange for admitting it. "I didn't even know he was here, I got here by accident but now I know –"

"Kara!" all looked to the doorway. Alex stood there, flushed and panting. "It's Zoom!"

Barry was gone before anyone could react; putting on his suit and in front of Zoom's cell before Alex or anyone else could say a word. Guards lay unconscious, or even dead, at the entrance to the cell area and Zoom stood outside of his cell, holding Jeremiah in the air by his throat, the head of the DEO helpless as Zoom looked to Barry.

"His life or yours, Flash!" Zoom growled, his free hand suddenly vibrating at intense speeds.

"Don't," Barry warned, his heart pounding, but before Zoom could even move his free hand to Jeremiah's chest, there was a rush of air, a loud crack and Jeremiah had vanished. Zoom was holding his suddenly broken arm as Supergirl appeared next to Barry.

"He said it earlier, Zoom, here you don't face the Flash alone!" Kara snapped as Zoom stood firm against the pair, the arm Kara broke to free her foster father healing in top speed.

"Fine!" Zoom said looking between the two of them. "You both will die."

Both Barry and Kara were ready however as Zoom hurtled toward them, they both moving aside as the man in blue sped through the wall behind them, they both following as Zoom retreated out of the Labs.

"How do we get him out of here?" Kara asked Barry as they regrouped outside STAR Labs, Zoom, too, having stopped to taunt them as Barry attempted to run around the figure to throw his lightning at him – Zoom easily ran from Barry's containment.

"Would you believe we have to get him to chase us again?" Barry remarked, they both following in the chase, pursuing Zoom this time.

"And then?" Kara asked, she running this time instead of flying, next to Barry.

"Throw me when we reach our top speeds. With any luck Zoom will go after me as I form a temporary breach to my world. Hopefully my world." Zoom was paying them back for capturing him, running as fast as he could through Central City and doing as much damage as he could too – it was all Kara could do to blow out fires as she ran passed them. "But I can't guarantee he won't find a way back."

"You'll have to stop him before he does then," Kara stated resolutely as they both grinned at each other, both feeling the strong connection, that same bond Barry had felt for the previous version of Kara – this one was exactly the same as that one and, had they not been trying to save two cities from the wrath of an evil speedster, either one could have pulled the other aside for a kiss.

As it were, for the second time that day Barry felt his feet leave the ground as Kara picked him up. "I'm faster flying," she called to him as they sored over the city, following Zoom across a river to National City.

Kara was right – in the air they caught up to Zoom easier and Barry couldn't help but wonder if Zoom was actually slower than he had been of late. Could it be that he hadn't had his fix, whatever that could be, while being stuck on this Earth? It was lucky if so as Kara dropped Barry to the ground ahead of Zoom and she called to him, "Ready?"

She too took to the ground again as they ran, faster than before, ahead of Zoom. "As I'll ever be!" Barry cried back as Kara, in one motion, turned, picked up the projectile that was his body and threw him.

Just like before, on Earth-3, the portal that allowed him transport between worlds opened and Barry hurtled into it, barely able to look behind him as a blue blur that was Zoom followed him in…

"Bye Barry," Kara sighed at the spot the portal had been. The Flash and Zoom had vanished from her earth at almost exactly the same moment and Kara watched, having circled back to where the blue portal had opened, with a tinge of sorrow to her heart. She'd had an instant rapport with Barry Allen the moment he'd shown himself to her in the cells at STAR Labs. Feelings she had never felt for anyone else, and even though he'd barely been in her life a day, she knew they'd both felt a connection that only those with the world on their shoulders could feel. He had Zoom to deal with, and she had the inevitable threat of her Kryptonian uncle.

Not looking back though, Kara took to the air as she headed back to the DEO, to make sure her foster dad was okay after Zoom's attack. He was tough as nails though, so he'd pull though fine.

-SuperFlash-

It had been a week since Kara Danvers had seen the Flash run in, and then out, of her life and she hadn't been able to shift the thought of parallel universes. He'd met a version of her on another Earth, so could there possibly be a Barry Allen on her Earth? And if so, who was he? What did his life entail? Was he the same sort of man as the Barry she had met?

These questions all lead her to this moment. Concealed up a tree in a suburban street of Central City, looking through the branches to the house across the road as a car pulled into the drive.

The driver's side door opened and a tall man with pointed brown hair, jeans, a tee and converses slipped out. He looked distracted but he was smirking to himself as he moved to the trunk of his car and unlocked it. At that moment a middle-aged, rather handsome, man opened the front door of the house Barry Allen had pulled into and marched over to the young man by the car.

"Just a few supplies, you said!" The man accused as Barry hoisted a grocery bag under his arm and handed another to his dad. Kara didn't need to use her super-hearing to hear this, the day was clear and the rest of the street quiet.

"Well it saves you going out," Barry reasoned as he and his father moved to the front door, a woman appearing in the frame, "and gives me an excuse to see you guys."

"You were only here yesterday, young man!" the woman at the door responded, but grinned nonetheless as she pecked Barry on the cheek, "but I'm always happy to see my son. You just missed Millie though, she's gone out with Wally again."

"Oh yeah?" Barry asked Nora Allen as he put the bag in the doorway in front of her and returned to his car, his dad lingering with a grocery bag under each arm as Barry got the fourth – and last – bag of food from his car, closing and locking the vehicle after. "She and Wally have been getting awfully close of late. I may have to speak to Iris…"

"Oh they're just friends," Nora commented absently as she picked up the bag Barry had left in front of her.

"You're honestly not falling for that are you?" Henry asked his wife as he waited for her to move back so he could take the food bags inside. "She's a rebellious teenager going out with an older man!" Kara could hear his voice call from the doorway.

"She's our rebellious teenage daughter going out with Iris' little brother. We've known the boy since he was a baby," Nora noted as she followed him in, Barry shaking his head as he moved over the threshold of the house and closed the door behind him.

Smiling from the tree at the perfect family moment, Kara however braced herself as she gently fell from the tree, landing noiselessly on the pavement and brushing the odd twig out of her hair and cardigan – she'd literally flown from work across the river to come to the Allen house, their unexpected visitor – before crossing the empty street and pausing a moment in parallel to the back of Barry's car. She assumed his dad's vehicle was parked in the garage.

"Okay Kara. A new friend. Just introduce yourself…" she muttered as he forced herself forward, butterflies now erupting in the pit of her stomach as she now forced herself up the steps to the front door and rang the doorbell. Instantly she let out a nervous breath of air as she heard footfalls make their way back to the door. What if this was a bad idea? What if he was nothing like the man she had met? It was too late to turn around now, though.

Barry Allen appeared from behind the wood, grinning at some joke one of his parents must have said as he looked Kara up and down, his smile faltering a moment. "Hi. Do I know you?" he asked pleasantly before coughing and adding more seriously. "Sorry, that was rude, I mean can I help you?"

The butterflies vanished in Kara's stomach as she couldn't stop grinning at the man, probably unnerving him slightly as she replied. "Not yet. I'm Kara. Kara Danvers, I just thought I'd say hi… so hi," she gave him a little geeky wave on the doorstep as he spluttered a 'hi' back at her again. "Sorry, this is really stupid. Can I come in? I mean you no harm but I need to talk to you." She wasn't a hundred percent sure what she was going to say but she needed to talk to him, to find out if he was the person she hoped he was.

"Oh. Err, yeah, come in, yeah" Barry responded with a smile, stepping back as Kara entered the Allen household, the door closing behind her.

Note: Hope you liked. Please review and look out for the footnotes soon!