The shadow peered around the corner, glaring it's eyes into the back of Barry's head.

Hiding in the darkness, after going through the breach, a second before it closed, only to end up at S.T.A.R. Labs. Fortunately the group of people, had moved from where the breach had sat, so the shadow was hidden, perfectly.

Barry had a strange feeling that someone else was occupying the area, someone unknown. He looked around and saw nothing, so he brushed it off, as his imagination.

"So Kara, would you like to properly introduce me, to your lookalike," Alex said, looking Marley in the eyes.

"Doppelgänger," Cisco corrected.

"This is Marley," Kara spoke, "She is from Krypton. Believe it or not, she is from our earth, Alex."

"Wow," she replied.

"Also, she's my twin sister," Kara muttered, quietly, and fast, but loud enough, that Alex heard every word.

Alex's mouth was wide open. It's like she didn't know how to react. Should she be happy that Kara has a sibling, from her real family, or should she be upset, cause Kara will spend less time with her, and more with Marley.

"Alex, you might want to close your mouth, before any bugs fly in," Kara noted.

The shadow silently laughed, somehow, too quiet, for Kara to hear. Not even their heartbeat could be heard.

"Right," she replied, "Wait, aren't you a lot younger than Kara?"

Before anyone could get any words in, Cisco said, "Barry, we should go, leave them to talk. Call us, if you need us for anything."

"Yeah, we should go," Barry commented, turning around, and walking out the door.

"Like I was saying, aren't you a lot younger than Kara?"

"I am. I'm ten years younger than Kara. I don't know how. Max-Mxy, do you know how?"

"Mxy? How long have you been here for?" Alex asked, her brain exploding.

"Goodbye," he replied, disappearing into thin air, before Alex's question could be answered.

Kara started to wobble, and fell backwards, hitting the ground with a loud thump, slightly cracking the ground beneath them.

*Flashback*

"Your pods co-ordinates, are interlocked with Kal-El's. You will follow him to Earth," Zor-El said.

"We're not afraid father," Marley and Kara said, at the same time.

"The trip is long, but you'll both sleep most of the way, and we'll be with you, in your dreams. You'll both journey to Earth, to look after your baby cousin, Kal-El. Because of the Earth's yellow Sun, both of you will have great powers on this planet. You'll be able to do extraordinary things," Alura said, leaning down, to explain to the young twins.

"I won't fail Kal-El," Kara said.

"And, I won't fail you," Marley mentioned.

"I love you Kara. I love you Marley. You must go. Now."

Marley ran back, and hugged her father, while Kara hugged her mother, goodbye.

"Go," Alura said, tears streaming down her face.

Kara and Marley were both in seperate pods. Marley's left first.

Kara had just left, when Krypton exploded. A piece of rubble, flew into the distance, just close enough, to see that it hit Marley's pod.

"MARLEY!" Kara screamed, hitting the glass blocking her, from getting out.

She wittnessed Marley, getting knocked into a wormhole, not knowing that it would send her to Earth-9.

When they had left Krypton, the girls were only nine years of age. Though, they were very intelligent.

Somehow, Marley got hit into a wormhole, a disruption, if you want to be fancy, taking her a few years into the future. But, once she made it through the wormhole, a breach opened, taking her to Earth-9.

Time is different in Earth-9. So when Kara was turning older, Marley and Kara's ages, were slowly separating.

Kara got hit by a piece of the rubble too, but instead of hitting her into a wormhole, she got hit into the Phantom Zone.

The force of the hit, from the rubble, made Marley and Kara, both hit their heads very hard. But, afterwards, there was no memory that they were sisters, and Marley couldn't remember Krypton, or her childhood.

Kara had fallen to the ground, Alex running to her side. A minute or two later, she opened her eyes.

"Thank god Kara, you almost scared me to death,"

"I'm fine Alex."

"Memories?"

"Yeah I had a memory flash of when we were just leaving Krypton. I know why you are so much younger than I am, and why you were on a different earth."

"Guys, I think that it's time to go back to our earth. Mon-El and Imra have already gone back, but J'onn still needs us back at the DEO. I think this can be explained when we get back."

"How do we get back?" Kara asked, "It's not like I have my extrapolater with me."

"Cisco can do it, he breached us to where you were."

"How could I forget. CISCO," Kara yelled.

"Yes Kara?" Cisco asked, him and Barry, running to the three women.

"Can you breach us back to Earth-38?

"You leaving already?" Barry asked, hoping she would stay a while longer.

"I have to get back to my city, to stopping Reign from hurting innocent civilians. Plus, J'onn needs Alex and I at the DEO, and I need to introduce Marley to everyone."

Caitlin walked into the room, "Do you mind if maybe Barry, Cisco, and I come check up on you sometime soon? You did have a really serious injury."

"Sure thing Caitlin," she replied, "We really must be going."

Cisco opened a breach, as Kara, Marley, and Alex stepped through, taking them to Kara's apartment.

*Meanwhile, on Earth-9*

Sebastian hadn't gone back to Dalton yet. He wasn't supposed to come back from Paris a few days early. Instead of going straight back to school, he decided to stay at home, and sort through some of his old stuff.

He was quite tired, so not much of his sassy self was around, so he was quite vulnerable.

Sebastian was told a few years ago, that he was adopted, but he had no idea who his biological parents were. There were a few belongings given to the Smythes, when he was adopted. Apparently, Sebastian was four, when he was adopted, but he remembered nothing.

Hours went by, as he came across a box that read, To Sebastian. It was like he had never seen this box before, it must've been hidden.

The box contained a CD, a picture of Sebastian, when he was really young, with his real parents, and a miniature teddy bear.

Sebastian looked in one of his boxes, to find an old CD player. Since barely anyone uses CD's these days, most people have them stored away.

After putting the CD in, Sebastian layed on his bed, trying hard not to fall asleep, and pressed play.

"Hi Sebastian, this is your father, Samuel. This message shall be given to you, on your sixteenth birthday. Happy Birthday, by the way, I'm sorry that your Mom and I missed twelve years of your life. It was one of the toughest decisions I've ever had to make, and I will regret it, everyday of my life. A few days after your fourth birthday, your mother, Sally, passed away, unexpectedly, in her sleep. Knowing that I couldn't look after you alone, with my job, taking up most of my time, I had to find an loving, caring family, to look after you. So I did, I found the Smythes. I had known their family for years, and they were looking to have a child. Unfortunately, they couldn't have any children. So they were happy to adopt you. Since you were only four, I had no way to look after both you, and your sister, Samantha. She was 13 when your mother passed, so she's able to stay with me for a few years, until she's old enough to look after herself. I hope that you knowing this, will give youthe answers, to all the questions you have, and I hope you live a wonderful life. Always know that the decision I made, was not because I didn't love you, it was because I loved you too much, to let you live a life with little support. Attached, is where you will find your sister, if you wish to know more, about family. Bye Sebastian.

He lay on his bed, contemplating between going to see his sister, or staying at home to sleep. He chose sleep, his sister could wait just one more day.

*Back to Earth-38*

Marley looked around, mesmerised by how cosy this place looked.

"Nice place you have Kara."

"Hey thanks Marley. Come with me, I'll show you the guest room."

"Hey, Kara?"

"Yeah Alex?" she asked, turning around, to face her.

"I'm going to the DEO. You should come by soon."

"Yeah, I'll be there in an hour or two."

Marley looked around the apartment, seeing pictures of Kara, with a man. She looks so happy.

"Kara?"

"Yes?"

"Who is this, in the photographs?" Marley asked, both of them stopping, "You look so happy in them. But now, you look so bleak."

"That's Mon-El, he's nobody. I honestly don't know why the photos are still up."

"Did he break your heart?"

"At first, no. Something happened, and he had to leave. Turns out he travelled to the future, lived there for seven years, got married, travelled back to the past, and lived in cryogenic sleep for twelve thousand years, with his wife. So yes, he did break my heart," Kara said, putting a clear emphasis on 'his wife'.

"Wow," Marley replied, seeing how Kara got, when talking about the subject.

They walked into the guest bedroom, Marley immediately seeing a book, sitting on a small bookshelf in the corner of the room.

"This book... It's the one I saw in my memory. Mom and Dad were reading it to us."

"Yeah. Weird thing is, somehow it ended up underneath the couch. No idea how that happened."

Marley giggled, "Does stuff often go missing, and end up being under the couch?"

"Actually, yes, yes it does," Kara replied.

Marley yawned, "How about you read Supertwins to me, and I can try to fall asleep."

"Sure thing.

Once upon a time..."

Five minutes later, into reading the book, Marley had fallen asleep, on Kara's shoulder. She thought it was adorable, but tried to not make a sound, as Marley looked so peaceful, and like she hadn't slept at all recently.

As Kara left the room, a sound caught her attention. It was a woman screaming for help. Kara's natural instinct was to jump out the window and save her, but instead, she tiptoed the window and tried hard to quitely jump out.

When she arrived at the place, where the scream for help originated, Kara saw a young woman, most likely, in her 20's, on the ground. The young woman had a gunshot wound to her chest, bleeding out, onto the concrete, that she lay on.

No one with a gun, was in sight. Kara quickly, and carefully carried her, to the nearest hospital, and made it back to her apartment, within a minute, accidentally waking Marley up.

"Kara?" Marley asked, as she got up and walked over to where she heard the noise.

"Oh, sorry Marley. I tried not to wake you."

"It's fine, I was half awake anyways."

Kara's phone rang, it was probably Lena. They had sceduled a lunch, for sometime this week. But it wasn't.

"Hey Alex."

"Kara, we need you down at the DEO, we have an alien loose in National City."

"Okay, Marley and I will be right there."

"Kara, I'm joking. Everyone here just wants to see you."

"Seriously Alex!" Kara replied, quietly yelling, with a mad look on her face, "Okay, I'll be there soon, I'll ask Marley if she wants to come."

Out of nowhere, Mxy appeared in front of the two women.

Well hello there Buttercup," Mxy said, walking to where Marley was standing.

Marley, and Kara, both jumped backwards, nearly crashimg into the wall behind them.

"Hi Mxy," Kara said, just loud enough, that only people in the room, could hear, "I was just about to ask Marley if she wanted to go to the DEO, so, we are kind of busy."

"Do you want to prank them?" Mxy replied.

"I bet, you have never uttered those words in your life," Kara responded, "I don't think we should."

"C'mon Kara, have a little fun, lift some weight off your shoulders," Marley said, interrupting.

"I guess. Alex did kinda do a smallish prank on me, just before, when I was on the phone. How would we prank them?"

"I would disguise myself as you, Kara Zor-El, and I would be you, and go around acting strange. Maybe I would confess my love to that horrible man, who broke your heart," Mxy said.

"I would pay money to see that," Kara replied.

"So it's settled, tell them that I didn't want to come. Kara and I will hide somewhere, so they can't see us, and we'll try our hardest to laugh as quietly as possible.

Kara, well Mxy, disguised as Kara, walked into the DEO. Kara usually flew in, but sometimes, she walked in.

"Hey Kara," Winn said, turning around from his computer screen.

"Hi Winn."

"Kara."

"Hey Alex."

"Did Marley not want to come?"

"She was busy sleeping. She seemed pretty tired."

Kara and Marley, hid out of sight, behind a wall, looking straight at Mxy, silently giggling, trying to contain all the laughter they had, bottled up inside.

Kara silently thought, "Good job Mxy. You do a really good impression of me."

Mon-El walked in, without Imra, so Mxy thought that this was the perfect time do prank him.

"Hello Mon-El"

"Uhh... Hi Kara."

"You know I'm deeply in love with you Mon-El. I don't care about your wife, I lourve you."

"Really, Kara?"

"Yes, really. More than I love my potstickers, which means, a lot," Mxy said, still pretending to be Kara.

If you listened carefully, you would hear two voices, giggling, and trying not to express their laughter.

"Kara, are you okay?" Mon-El asked.

"Never better," Mxy replied.

"You seem unlike yourself."

"Well, you know, travelling to another earth, really changes someone. It changed me."

Mxy was acting very unlike himself, which was strange. No one would ever think of seeing him, this down to earth.

Alex walked over and whispered, into Mon-El's ear, "You realise Kara is actually hiding over there, giggling."

Mon-El turned around, to see Kara stepping out from where they were hiding, Marley staying behind.

"Sorry Mon-El, we thought it was funny. Uhh... That would be Mxyzpylk, disguised as me. But he somehow did a great impression of me," Kara said.

Mxy changed back into his original form.

"Mxyzptlk. I should've known," Mon-El said.

"Well how could you? I did an amazing impression of Kara Zor-El."

"You know, I'm still mad at you, for what you did to me. Teleporting me to the DEO wearing like nothing, was not fun."

"I agree, it was not fun. It was Fun-ny."

Kara secretly rolled her eyes, at the behaviour of the two men.

"Marley, come out. You were supposed to follow me," Kara said, looking over to the corner, where the two had been hiding.

"Hi," Marley said, very softly, waving at everyone, slowly walking out, to where everyone was huddled.

"Uhh... Kara... Who is this? She looks exactly like you," Winn said, entering the semi-circled shape huddle.

"This is Marley. The rest, I'd prefer to tell to everyone, at once, instead of telling it multiple times."

"I'll tell James, and J'onn," Winn said.

"I'll go get Imra," Mon-El said.

"And, I'll get Mom," Alex told Kara.

"Kara, after this, we need to read Supertwins again. I fell asleep at the start of the book."

"Yeah, five minutes into the book, and you were fast asleep, it was kinda funny."

"Hey, stop," Marley responded, nudging Kara.

*Meanwhile, on Earth-1*

"Kara seems pretty cool, I mean, I haven't really talked to her much, but she seems so sweet," Cisco said, looking at Barry, in the Cortex, alone.

Barry unknowingly blushed. He was unaware that such thing was happening.

"Hey guys."

"Hi Iris."

"Barry, what are you blushing about?"

"I'm blushing?" Barry asked Cisco.

"Yeah dude, you started blushing just now, when we were talking about Iris."

"You guys were talking about me? What did you guys talk about?"

"How cool you are, and all," Cisco replied.

Barry just froze, he didn't know what to say, so he sped off.

"I feel like you are leaving some details out, Cisco."

Before Cisco could respond, an alarm went off.

He called Barry, wishing he didn't speed away, seconds earlier.

"Barry, the meta-human alert app went off. Meta spotted at Jitters."

"Okay... I'm on my way."

Barry rubbed his eyes, when he saw who the meta-human was. Well they aren't really a meta-human, but Barry still had to wonder how, and why he got here.

"Blaine?" he asked.

"Guess again."

"Music Meister," Barry said.

"Correct," Music Meister replied.

"Why are you here? Come to teach someone another lesson?"

"Well, of course, why else would I be here?"

"What kind of lesson is this?"

"A lesson that I can't tell you. That part you have to work out, on your own. As for now, I have a city to torment."

"I'm not gonna let you."

"Yeah, like you can stop me," Music Meister replied, with sass, "I still have all the powers of Supergirl, so unless you can fly, you can't stop me."

Music Meister flew away, with Barry following him, running underneath him.

Music Meister stopped in front of a bank. Immediately, he used his heat vision, to cut the building in half.

Since it was the middle of the day, the bank was full, so Barry had to get every person out.

Half a minute later, everyone had gotten out of the bank, safely, before it collapsed. Music Meister had flown off somewhere, out of sight.

"I thought Music Meister said, that he's actually a good guy," Barry muttered to himself.

"Oh, I am," Music Meister said, flying right into Barry's face, and punching him, in the stomach.

Because Music Meister had Supergirl's powers, his punch sent Barry flying across the street.

Barry struggled to get up. Instead, he looked around, for a way to stop Music Meister.

"Music Meister, what is the lesson you are trying to teach me?"

"Like I said earlier Barry Allen, you have to work that out by yourself. For now, try and stop me."

Barry ran 5.3 miles away, ready to do the same thing he did, when his childhood bully, became a meta-human, and had skin, that turned to metal.

He ran, as fast as he could, going slightly slower, than his fastest speed. As he reached Music Meister, Barry was ready to punch, but instead of his fist, hitting Music Meister's face, it was caught, with Music Meister's hand.

Barry was flipped upside down, and punched, across the street, again. This time he was bleeding, and he had passed out.

Music Meister took this as the opportunity to start his plan. He ran over to where Barry lay, and grabbed Barry's passed out body.

People had gathered a croud, and the news were filming this.

Cisco and Iris were trying to talk to Barry, but he wouldn't respond. Caitlin was on her way, but couldn't get to S.T.A.R. Labs in time, cause by the time she had gotten there, Music Meister was opening a breach, and pushing Barry through it.

Cisco, Iris, and Caitlin, were all at S.T.A.R. Labs, watching this happen on the computer screen, seeing Barry pushed through a breach.

Cisco tried to track where the breach went, but somehow he couldn't.

"Guys, I can't track the breach. I don't know where he's been breached to," Cisco said, starting to pace, back and forwards in the Cortex.

"Cisco, stop worrying so much, we will find Barry, and he will be okay," Caitlin told him, walking over to where he had stopped, and placed her hand on his shoulder.

"Yeah, what Caitlin said, we'll find him, and he'll be alright. I'll go tell my Dad, and you and Caitlin, work on finding him.

The shadow looked around the corner, still hidden, and still unknown to the people around. The shadow was extremely quiet, not even someone with superhearing, would be able to hear it.

It had been following around Caitlin, everywhere she went, but she never noticed anyone following her. Though, she did stop a few times, as she felt like someone was there, but no one was in sight.

It's like this shadow, was invisible, and unseeable, to the naked eye.

The shadow watched as Iris left the Cortex, and then moved it's eyes back to Caitlin.

What no one had noticed, is that somehow, Music Meister had done something to Iris, and it was unknown to everyone. Only then, when she left, would it start coming into effect.

*Earth-38*

James and Eliza, had both arrived, at the DEO, both getting an emergency alert, that required them to get there as soon as possible. Imra, and J'onn, were already in the building, coming over to the now, big group of people.

Kara flew Eliza, from Midvale, to National City, as this would be the fastest way, for her to travel.

The reactions when they had seen Marley, was priceless. They were all so shocked, that they were speechless.

Alex hadn't heard what Kara was going to explain, so she made everyone be quiet.

Kara led everyone over to a private room, where everyone sat down. Kara and Marley stayed standing.

"So... You guys are probably wondering who this is," Kara said.

A pile of mhm's, were heard, suggesting that Kara should carry on.

"This is Marley, my sister."

Everyone was even more shocked than last time. Exept Alex, cause she already knew this part.

"Hi," Marley said, shyly waving to everyone.

"So... Only Mon-El, and Imra, know this bit. Reign dropped me off a building, and somehow, I fell through a portal, a breach, is what Cisco called it, and it took me to Barry's earth.

Mon-El and Imra came through a breach themselves, using the interdimensional extrapolater that Cisco had given to me, and helped me to recover.

I was badly wounded, and apparently, a small piece of kryptonite, was lodged somewhere in my body. Luckily Barry was able to get it out, by phasing his hand through my chest.

But, as I was recovering, Mxy here, grabbed me, and breached me to another earth. Earth-9. Where Marley was.

I found it extremely weird, when he took me to meet his 'girlfriend', and his girlfriend looked exactly like me.

At first, Barry and I thought, she was my doppelgänger, but then Mxy told us, we were sisters.

A few memory flashes, here and there, but I now remember, how Marley ended up on Earth-9."

Kara finished explaining to the group of people, and left everyone shocked and curious.

Marley had decided to go out to the main area, and show off some of her powers, which were the same as Kara's. Marley's powers were a little weaker though.

Marley landed on the ground, after hovering, slightly off the ground, not wanting to go high, incase she couldn't control her powers.

And suddenly, a breach opened, in front of everyone.

"Uhh... Guys, what is that?" James asked.

"That would be a breach," Kara responded.

"Who do you think is coming through it?" Winn asked Kara, stepping back, and away from the breach.

"I don't know. Maybe Cisco, maybe Bar-..."

Kara got interrupted, as two figures appeared through the breach, one she immediately recognised, on the ground, unconcious, the other, took a moment, to figure out.

"Blaine?" Kara's twin said, stepping closer, to get a better look, at the figure.

*Back to Earth-1*

Iris had gone to tell Joe, that Barry had gone through a breach, and that Cisco couldn't find him. Since Joe wasn't picking up his phone, she decided to take a walk, to the precinct.

On her way, she passed a young man, who looked familiar to her. Iris looked closer at the man, thinking he looked hot. For some reason, her mind, trailed off telling Joe, that Barry was in trouble and led to her thinking about this man.

"Sorry Oliver, I'm replacing you on my three list, with this hottie," she muttered, quietly.

If only, she could see knew who it was...