AN: Hello everybody, this is a story I wanted to write for a little while now. Almost since I've watched "For the girl who has everything". In this episode, the Black Mercy version of Kal'ex and Alura use the Argo fever as an excuse and try to convince Kara this isn't a dream. I wanted to know what the Argo fever would actually do if a kryptonian was infected and I came up with this story.

Also this has nothing to do with the Kadam serie.

As usual, I have to warn you. I'm not a native English speaker so there might be mistakes and I apologize for it.

Let's start ;)

It had been a month now since Kara had revealed herself to Cat Grant. They had this little conversation on Cat's balcony that Alex had suggested. After the Black Mercy incident, The Queen of all Media had made it clear to her assistant that her conviction of her being Supergirl hadn't gone away. She had never said it directly but there were staring looks everytime Kara would return to CatCo after Supergirl had made an appearance, allusions and many comparisons. Kara had told all of that to Alex who had advised to come out. Cat knew anyway.

Starting from there, everything related to Supergirl's duty was a lot easier of course. Kara, James or Winn didn't need to make up some crazy and lame excuses anymore. But, one thing that hadn't changed, was Cat's attitude towards Kara. Being Supergirl didn't change the fact that she was her assistant and her job would remain the same. Thank God for Kara. The young woman was very thankful that her boss didn't want to fire her again. Or maybe she had conviced her on the balcony during their little conversation. Kara would keep her job as long as all the Supergirl exclusive news would be owned by CatCo and CatCo only. Which wasn't a big deal since it was already almost the case.

So today wasn't very much different than any other day at work. Lattes, layouts, meeting, salads... Occasionally, there was a Supergirl emergency and that's what was happening right now.

"Miss Grant." Kara called running in her boss' office and pointing at the window

"Stop telling me. Just go." Cat said without even looking up.

She was saying that just to stay in character but in reallity, she liked that her assistant was warning her everytime she needed to change. That way, she was a bit reassured by knowing where she was.

Kara made a quick turn on her heals and headed to the roof. A split second later, Supergirl was flying between the buildings of National City, on her way the the DEO.

When she got in the base, a team was already preparing and Alex and Hank were with Vasquez, watching the screens.

"What do you got?" Kara asked stopping next to her sister

"We found a Fort Rozz escape." Vasquez said showing a picture on the screen

"And a nasty one." Hank added

"What do you mean?" Alex questioned a bit worried

"This one isn't like the other prisoners. He doesn't have a proper name, he was registered as Subject-17. According to the Fort Rozz records, this thing has been created in an illegal lab on Krypton. They used an orphan baby and experimented on it."

"That's horrible." Kara said with digust when she took an other look at the picture.

It was huge, had brownish skin with a pale face, black-eyed and completely bold.

"Is there any way we can reason with it?" Kara asked crossing her arms

"That's the problem. It wasn't sent to Fort Rozz because of something it planed or did. But because it doesn't think. This thing has no mind. Its only purpose is to survive by any means necessary. It was disigned to kill to survive." the director explained

"Yeah... The backpackers that found it is lucky to be alive. They heard it groan in the mountains and ran away." Alex added.

Kara seemed disapointed but understood she had no other choice.

"It's hiding somewhere in the caves. We have established a restrained search area around the mountains based on the backpacker's situation and the satelites images." Vasquez stated

"And what does make this monster so nasty?" Kara asked repeating Hank's words

"Enhance vision, super-strength and...sonic discharge."

"What does that mean?" she wondered

"It means that it can knock someone out just by screaming." Alex started. "And since you're the one with super-hearing..."

"It can hurt me." Kara finshed with aprehension.

The DEO team was composed by ten highly trained agents, lead by Alex. They all had helmets with a torch on them, a riffle and a hand gun. They also had a big truck to transport Subject-17. The black trucks stopped about two hundred meters from the closest cave.

"Do you hear anything?" Alex asked to her sister.

Supergirl focussed for a few seconds, tilted her head on the side towards the caves.

"I'm not sure." she said before looking up. "Stay here."

Supergirl flew upward and stopped when she had a clearer view of the mountain. She tilted her head again and listened. When she was satisfied, Kara landed back next to Alex.

"It's in the cave after that one." she affirmed pointing at the closest cave

"Alright, let's move out." Alex ordered.

The whole team followed Supergirl in the steep trail. After a few minutes, Alex ordered to stop right at the entrance of the cave.

"Sir, we have a location." she said to Hank using her earpiece

"Do not hesitate to engage. And don't let it scream."

"Copy that. Once we go in there I want complete silence. We stay together, no one gets more than a feet away from the agent in front of him." Alex commanded.

All the agents nodded. Three of them took the lead, followed by agent Danvers and Supergirl, the other seven were right behind them. After a very silent and long minute, a groan escaped from the bottom of the cave. This made the agents stop, waiting for the beast to come out. Alex held her fist in the air as an order to stay put. A few seconds later, when nothing more happened, she opened her hand and waved it forward. The cave was very deep and the sound of their footsteps seemed to resonate the more they would go deeper. Or maybe they were just hearing the sound of their own heartbeat pounding in their ears.

The team kept walking in the dark for an other five minutes before stopping again. This time, the beast was extremely close. And not only Supergirl could tell. Kara looked at Alex in search of support. Her face was so pale under the artificial light of her helmet. But Alex looked fierce and determined. Kara searched for her heartbeat. It was faster than usual but not as fast as some of the other agents around them, not as fast as her own.

Everyone startled when the monster groaned once more. But it wasn't like the one they had hear before. It knew they were here. Without further hesistation, Alex gave the go signal and every agents jumped out of their hiding spot. They started to shoot at the exact same moment the beast was turning to face them.

"Weapons free!" Alex scream as she started to shoot too.

The monster seemed surprised and hurt by such fire power and took a step back. When it got on its knees, Supergirl intervened.

"Stop!" Alex ordered.

Kara walked carefully towards the monster but quickly stopped when it looked up. The bullets had barely penetrated his skin. Subject-17 screamed with rage and sent his arm to slam Supergirl against the wall. Kara hit violently the wall and fell on her side. The agents started to shoot once again but it seemed like the monster wasn't affected by the bullets anymore. It didn't care. By the time the beast was up, Supergirl punched him hard with both of her fists. It made it fall on its back a few meters away. Kara flew towards him to strike again but it surprised her by its speed. The monster caught her by the cape and slamed her on the ground without droping her. It did it again three times before his attention shifted back on the humans. Kara was lying in a small crater, struggling to stay concious. Alex had waited for her sister to be out of sight to try her theory. She pulled out her kryptonite bullets and shoot three times in the back. It wasn't affecting it like it was Kara but at least the bullets were penetrating way deeper.

"Use kryptonite!" she screamed

The agents took a few seconds to change their bullets. Unfortunatly, it was enough for the beast to get to them. Alex was still shooting but it was still walking. Two meters from them, Subject-17 stopped when Supergirl cercled her arms around his neck. The young hero was determined to get this thing down.

"Back away!" she screamed as the monster was trying to reach her.

Alex hesitated but decided to make her soldiers step a few meters back. They were ready to shoot again.

Supergirl was still holding even if the alien was spining with force. At one point, it suddenly stopped, his back turned to the humans, and took a big inspiration.

"Supergirl, leave!" Alex shouted as she knew what was about to happen.

But Kara didn't listen. The beast used his sonic discharge. Kara felt a sudden pain in her ears and removed her hands. The pain was so strong, that she didn't controled her fall and crashed on her knees. The humans were also covering their ears as much as they could. A few used the wall to support themselves. Fortunatly, the scream wasn't direct, but the structure of the cave amplified it.

Kara was still on the ground, her hands firmly gripping her hair. The young woman was screaming and was overwhelmed by the power of the scream.

As soon as the discharge was over, Alex rushed over her sister and knelt next to her.

"Supergirl, are you ok?" she asked

But there was no answer. It was like Kara was deaf. There only was this extremely high pitch wistle in her ears. The young woman didn't hear her sister, nor the roaring monster walking towards them.

"Shoot this thing down!"

And for the next thirty seconds, the only sound in the cave was the sound of the guns firering green bullets and the agony groans of the monster. The alien was backing away at each bullets it took, diminishing the danger at each step. Finally, the beast knelt down and fell, face to the ground.

"Sir, it's over. We got him." Alex said waving to the agents to strap the alien up

"How is Supergirl?"

"Not good, sir." the agent stated. "Supergirl?" she said putting worried hands on Kara's back.

This made the young hero startle and suddenly look up to her sister with tears of pain in her eyes.

"Are you ok?" Alex asked seeing the red line of blood sliding from Kara's ears to her neck.

The young woman stood up quickly and backed away a little, staring at Alex with panic.

"What is happening to me!?" Kara shouted

The agent caught her wrist to stop her and reassure her. A sudden terrifying thought struck her.

"Kara, can you hear me?" the older sister asked a few centimeters away from the hero's face

"Alex, the wistle...it's deafening!"

"Hey, calm down. We're going to fix this." she assured cuping her cheeks.

Even if Kara couldn't hear her, she knew Alex was saying reassuring words. Her presence only was comforting.

Alex walked Kara outside the cave, following by five agents who were dragging Subject-17. The younger sister was afraid it was dead for a moment, seeing all the green holes in its chest. But she figured it was alive when the extract team brought the special truck and the agents took the time to cuff the monster.

The wistle was going weaker since they had reached the surface and Kara could now hear low noises like someone closing a car door. The special truck and one of the car went back to the DEO while three other agents stayed with Alex and Supergirl. When Alex had tried to get her in the car but Kara told her she was starting to recover and needed the sun. They waited two minutes before the young woman started to smile.

"Can you say something?" Kara asked Alex still with a loud voice

"You're shouting." she smirked

"Hey, I can hear you." The young woman smiled

"Can we go back now?" Alex asked impatient. "You need to get checked up by a doctor."

"Fine..."

A few minutes later, the Danvers sisters were in the medical bay. Doctor Hamilton was examinating Kara's ears.

"Luckily the scream wasn't a direct shot so the damaged aren't permanent. The cave made it louder." she started. "How well can you hear?" the doctor asked

"Much better now. There is still a small wistle in the background but my super-hearing is back." Kara said jumping from her stool

"That's good news." Alex stated relieved

"The wistle might take a while to stop though. I'm not sure but you could have some kind of tinnitus." she warned. "But don't worry. Nothing serious." Hamilton corrected seeing the concerned faces around her. "Agent Danvers, you're next."

"Why?" Alex protested making Kara chuckle

"You were exposed too. I want to verify there isn't consequences on the human brain."

Alex sighed heavily and sat on the stool, ready for all kind of test.

"Don't take it this way. Everyone on your team is going after you. I wouldn't want to make any jalousy." the doctor smirked.

Kara thanked Doctor Hamilton and smiled at Alex before going to the main hall.

There, Director Henshaw was watching his agents putting carefully Subject-17 in a secure cell. The alien was still uncounscious hopefully.

"How are you feeling?" Hank asked as he saw Supergirl standing right next to him

"Lucky I guess... Glad I can still hear." Kara answered crossing her arms

"We were lucky this thing has the same wickness as you and that Alex even thought about it."

"Doesn't it prove that there is still something Kryptonian and sensient in there? I mean all it wanted was to be alone its cave." Kara shruged

"I know you're not very happy with all of this. First Bizarro, then Subject-17... But I can't take any risks." he paused to confirm his authority. "What if someday, an other backpacker walks in a cave and end up face to face with a monster who won't let him leave alive? I hope you understand I only want the security of National City, and by extend, of all humans." the director affirmed with a very formal tone

"Yes, I know. It's just...It's hard to imagine that thing was once a kryptonian just like me!." the young woman sighed.

There was a few seconds of silence where the two were watching the alien slowly waking up through the surveillance camera.

"Is there anything you want me to do?" Kara finally asked

"No, thank you. You can go back to CatCo." Hank assured with a small smile.

Kara nodded a formal good-bye and left, feeling something was wrong with her. But she couldn't tell what. It was a background sensation, almost like a presentiment.

AN: I hope you like this first chapter. Next, the Argo fever will really affect Kara and we will learn more on that disease.

Don't forget to review, it's always a plus. I will respond to you happily ;)