Hello everyone! I'm back, it has taken me a while to start writing again purely because of exams and lack of ideas. Ever since the finale of Supergirl I have been inspired to write a new, darker story. BEWARE THERE ARE SPOILERS TO THE SUPERGIRL SEASON THREE FINALE, ISH- so just a pre-warning.

I hope everyone is well, and I'm back on it guys!

Also, as this is going to be a dark story, I want angst and lots of it. You tell me what I should do and I'll see if I can add it!

Thank you all!

Night time in National City was always a quiet affair for Supergirl. Granted, every now and then you'd have the odd car jacker or the burglar but other than that, it was blissful and nothing went wrong.

Supergirl would just hover in the sky, sort of meditating. It was peaceful.

Suddenly, Kara picked up on something. Her eyes snapped open as she heard what sounded like a panicked heartbeat. Kara only listened or honed in on specific heartbeats. She mainly focused on the ones that were close or like family to her.

Kara knew Lena's like the back of her hand.

That's who's heartbeat she picked up.

Supergirl then shot straight over to L-Corp. As she landed in the office with a thud, she looked around and as she did, there was no one in sight.

Kara carefully walked around the office. Her eyes darting across the room and her ears trying to find one particular heartbeat. Panic washed over Kara as she found that she could no longer hear it, so she decided to use her X-Ray vision to look through the walls. There was only problem with that, the walls were filled with lead.

Kara sighed heavily, before calling out Lena's name, "Lena!"

Nothing.

Kara approached a book case that seemed slightly pulled away from the wall. She frowned, being cautious as she walked toward the bookshelf. She stopped as she saw the doorway, "You read about this in weird mystery books, the hidden doorway." She muttered to herself before opening it further to find a set of concrete stairs. Kara treaded carefully down the stairs and as she did she heard a faint thump of a heart.

Her pace sped up as she almost ran down the stairs. As she reached the bottom, she saw a stain on the floor.

A blood stain.

Kara's mouth went dry instantly, and her own heartbeat suddenly went a thousand miles per minute, "Lena." She called out in a very cautious tone. She stepped around the fresh blood stain on the floor and carried on further into the dark abyss, using what she could of her X-Ray vision to get through.

Lena sat in her office, finishing the last of her paperwork for the day. Reign was defeated and she was still analyzing the rock that sat in front of her. Harun-El, black Kryptonite. As she put her files away, she glanced at it.

Lena picked up the rock, staring at it with wonder and intrigue.

"What are you?" She muttered to herself. Of course, she was aware that the rock split Kryptonians in two, she had seen it herself with Reign and Sam, but now she wondered if she could push the boundaries and go further than just what she had just witnessed.

A phone began buzzing on the desk. Lena turned, placing the rock down. She then picked up the phone and answered it, "Yes, Miss Techsmacher?"

"Ms Luthor, the results from the black rock have come back. I think you should come and see." Her breathing sounded jagged, "I saw the results with Reign and how it split her from Sam...But these results...If Supergirl came into contact with it, well, it could mean...Disaster."

Lena stared at the rock while keeping the phone close to her ear, "How so?"

"It doesn't just split a bad Kryptonian from a human, it can split their personalities. This is going to sound crazy, but imagine the angel and devil on your shoulder that we all say we have. That happens, only literally. You'd have two Supergirl's. One good, and one bad." Miss Techsmacher explained.

Lena frowned heavily. She then heard something fall in her office.

"Ms Luthor?" Miss Techsmacher said with concern as Lena went quiet.

Lena's brain caught up with her, "I'll look into it further. For now, shut down everything, but save all the data that you have securely and then go home for the night."

"Is everything okay Ms Luthor?" Miss Techsmacher asked with concern, having a feeling that everything wasn't as it seemed.

"Yes, everything is good." Lena replied, staring into the corner where she heard the sound, "Good night Miss Techsmacher."

"Good night, Ms Luthor." Miss Techsmacher replied before cutting off the call.

Lena placed her phone on her desk, before approaching the dark space, "I know you're there."

Her voice was void of fear.

A figure stepped out. Covered in only what seemed to be a blanket.

Lena audibly gasped as the figure stepped out. It struck her that this person looked exactly like Kara. Now she thought about it, Kara had been missing for weeks and only appeared every now and then. Her jaw dropped slightly, "K-" She began. Shock set in mostly.

The Luthor was lost for words. The woman's face before her was blank. More or less a stoic expression.

"Kara?" Lena eventually asked. The other woman tilted her head to the side, frowning heavily as if she was confused by the name, little did Lena know that this woman knew exactly who she was. This Kara knew her identity, but she was even more cunning.

Eventually, a small smile spread across her face and as she identified Lena's face, "Lena." She breathed.

Lena smiled nervously at her. Something told her that this whole situation was wrong, she just couldn't figure out how or why, but her gut was telling her that this was all wrong. Something deep down was telling her not to trust this person, but Lena saw her best friend in front of her.

Her Kara.

How wrong she was.

This was not her Kara at all. This was anything but Kara, granted they were the same person but the Karun-El had split one person in two.

Literally.

Kara walked into the basement and found Lena unconscious on the floor, with blood spilling from the back of skull. It was then that Kara rushed over to Lena. She knelt down, putting her hand where the blood was coming from. As she pulled her hand away, it was covered in blood.

She panicked instantly, and suddenly turned when she heard footsteps.

"Who's there?!" Kara called out.

Nothing.

Kara turned her attention to Lena. As she did, she was suddenly struck across the head. The blow was hard enough to knock her unconscious.

The other Kara stepped out from the shadows holding what appeared to be some sort of hammer with a head made with a block of Kryptonite. She stood where Kara and Lena were. Two powerful women struck down by one almighty being.

"Hello, Kara." The other woman quipped as she stared down at the caped hero.

Still draped in a blanket, the other Kara knelt down, staring at the gaping wound on Kara's head. Her eyebrows scrunched together, "I am sorry about this, but there can only be one of us. It's a shame, I am better than you. Stronger than you. I'm everything that you can never be." Her voice dripped with sarcasm and almost sounded venomous.

The other stranger stood straighter, almost glaring at the unconscious Supergirl. She then turned and walked away.