Disclaimer: I do not own Supergirl or the characters.

A/N: This is set some time after 2x15 'Exodus' and assumes that Kara now knows the truth about Mon-El and did not take it well.

It is written for the prompt sent by Bobpandas where Kara trades herself for Jeremiah and is tortured by Cadmus, believing Alex hates her, whilst no one realises she is missing.

"You okay?" J'onn asked as he walked out onto the balcony where Kara was looking out over the city.

"Great." She said not looking round.

"Want to try again?" He asked moving to stand next to her.

"Seeing I have no job, my boyfriend has been lying to me since day one and Alex is really torn up over Jeremiah, I'm great."

"It'll get better." J'onn assured her.

"I just feel so lost and so disconnected from everyone."

"Does this also have something to do with Alex saying you had to choose whether or not you were part of the family?"

"How do you even know about that?" Kara asked.

"I'm a telepath and Alex has been radiating guilt." J'onn said.

"No. It doesn't have anything to do with that." Kara lied.

"Just because I can't read your mind doesn't mean I can't read your face." J'onn pointed out.

"Fine. At the time her words really hurt. Ever since I arrived in Midvale I was made to feel part of the family. Even in the early days Alex may not have wanted me, but she still referred to me as family."

"Families have arguments all the time. Doesn't mean you're not family." J'onn said.

"But I'm not. Not deep down. We don't share blood."

"Family is more than blood ties."

"Maybe, but maybe deep down it isn't. Maybe she was right. I questioned Jeremiah's intentions and his loyalty. Real family wouldn't do that. I mean Alex's faith in him was unwavering."

"Family is a lot more complicated that that. Family can be cautious and family can make hard decisions. Take your mother and Astra and they were twins." J'onn argued.

"It wasn't just questioning Jeremiah though." Kara said. "I questioned Alex, I sided with you and said she shouldn't be working the case. The last time I saw her that hurt was when I told her we weren't really sisters during the red-K thing."

"I'm sorry I put you in that position." J'onn said.

"It's not your fault." Kara said. "If I were a better sister I would have helped Alex rather than turn my back on her. If I had she never would have ended up on that ship and we would have Jeremiah back."

"You don't know that." J'onn said. "What we do know is Alex is safe and Jeremiah is good."

"And a prisoner of Cadmus, assuming they haven't killed him." Kara said sadly.

"You saved Alex and all the people Cadmus put on that ship." J'onn reminded her.

"But not Jeremiah. I failed Alex again."

"That's not true. Alex doesn't believe that." J'onn countered.

"You said Jeremiah betraying us would change everything, it would make us stronger. But it doesn't feel like that. There is so much distance between Alex and I now. Alex and I have barely spoken since I sided with Mon-El over Jeremiah."

"Both of you have rather a lot going on in your lives right now." J'onn said.

"Do you mind if I take some time off?" Kara asked out of the blue.

"Sure. Why?"

"Last time I felt like this I got some help from Barry, maybe he can give me help again."

"You want to go to a different Earth?" J'onn asked.

"I do. And the device he gave me will let me do that."

"You really think Barry can help?"

"I do."

"Okay. But make sure you tell Alex."

Neither J'onn or Kara saw Agent Rose move away from the wall he had been leaning against whilst eavesdropping. Nor did they know he sent an email reporting the conversation to his other employer.

-00-

As Kara took to the skies a familiar and unwanted voice rang painfully in her head.

"Hello Kara Zor-El." Lillian Luthor said. "Listen very carefully. I am prepared to make a trade. You for Jeremiah. Come alone to the the old National City mental asylum at nine tonight to make the trade. Tell no one. If you do, he dies. If anyone follows you or ever looks for you he'll die. Even after I have released him I can hunt him down and kill him so make sure no one doubts your reason for disappearing."

-00-

"Alex can we talk?" Kara asked approaching Alex at the alien bar.

"Now is not really a good time." Alex said. "Maggie and I have reservations in twenty minutes."

"Oh okay. Sure. I'll just put it in an email." Kara said.

"Um, okay. If that's what you want." Alex said.

"Have a good night." Kara said before heading to the entrance walking past Maggie as she did so.

"Hey Kara, everything okay?" Maggie greeted.

"It's fine. Look after her." Kara replied glancing at Alex.

"Sure." Maggie said surprised by the request.

-00-

Kara returned to her apartment and sat on the couch regretting not being able to say goodbye to Alex, but knowing it was for the best. Knowing how bad she was at lying to Alex she assumed a carefully phrased email would be questioned less than a face to face conversation.

Pulling out a notepad she wrote a letter to Alex which she sealed in an envelope with her mother's necklace. She then put the envelope under her bed with the device Barry had given her. She then wrote an email to Alex explaining she had gone to see Barry on Earth one before setting the mail programme to send it in eight hours. Checking the time she turned off her phone and placed it on her coffee table before turning the lights off and flying to the rendezvous.

-TBC...

A/N: Thanks for reading and reviewing. I will try to get the next chapter up tomorrow.