It had to be the dead thing. Or perhaps it was the knowledge that they were unlikely to have ever brought down the death star without his sacrifice. She'd briefly considered it being part of her reaction to thinking about Alderaan, though that thought had been dashed pretty quickly as she tended to just be angry about Alderaan, not nervous.
In reality, the reasons behind her nerves weren't important. She'd get over it with more exposure to him and unfortunately for Kenobi, he was likely to be stuck there for a long while.
Evaan nodded. "They go through all the time. Half of what makes life livable here is what they bring back. And I don't just mean parts to produce the power we have, I mean things like food, clothing, essentials. Apparently, they lead to different places and times and they never seem to be the same for long. People go in but they always seem to come back. The people who disappear from here are said to just vanish."