It is perfectly natural for people to feel on edge or uncomfortable around Astartes. They are chimeras. Voluntary, but no longer fully human nonetheless.

He looks over at her--clearly military, but not quite Astra Militarum. Another cause for concern--they had been bringing more and more warriors here. While it was a pleasant change from all the elves and sorcerers, it was a cause for its own flavor of concern.

"I do not know, but there must be some trick. There is a quest," he riffles through the postings till he finds it and shows it to her. "It seems ludicrous. Just gathering flowers. At night. If it seems innocuous here, I would advise thinking that they are not telling you the entire story."