<Emily wake up again>

Emily wakes up in her bed, laying on her side. Lena is sitting on the floor in front of her, leaning against the window, with her arms over her knees and her head resting on them. She looks very pale. A few thoughts flash through Emily's mind in quick succession: asleep or dead — she moved a tiny bit, she's breathing — asleep, phew.
Emily moves into a more comfortable position. Lena zuckt zusammen and lifts her head, looking disoriented for a moment.
She says in a weak voice: So you will live.
Emily sits up.
How long has it been?
About three days.
Have you slept at all?
Here and there a bit.
You need to sleep.
Funny you should say that... I couldn't sleep because I was worried about you little devil.

They get up and walk down the hallway towards the main control center.
While you were unconscious, I managed to get in touch with someone on Earth. Well, they really got in touch with me.
So it is true that there are still people down there... How did they do that?
There is some old, long disused radio equipment in the control center that they reactivated.
How?
That's something you're gonna have to ask them. Apparently, there is no way to fully disable it. They seem to have extensive technical documentation on all of our systems. I only noticed their activity when I heard a phone ringing in here and went to investigate.
They reach the door to the control center module. Lena punches her code into the keypad, a computer voice says access authorized and the door slides up.