If Eira noticed the charged atmosphere around her, she affected not to notice it. Her eyes were bright chips of hazel in her face, warm in a way that freshly-tilled earth is warm under the sun, and brilliantly alive with something like an inner fire. Of course, to most others, she merely seemed like an excitable human, one of those people who live so vibrantly in their skin that it's impossible to hide. Only the sharp angles of her face and the near-predatory gleam of curiosity in her eyes hinted at anything else, as she crouched to be level with the feline and extended her hand slightly from her body, her fingers loosely clenched in an invitation for the animal to catch her scent.
"Well, he's quite a beauty! Where did you get him? I've heard of stories of panthers like him from the Kishahn Jungle, but I haven't been lucky enough to see one - yet." Her adoration of the cat was obvious and almost charming, the way that a young child's is - the delight was so obvious on her face, it was impossible to miss. As one of the supreme predators of the land, of course Eira favored other such animals, but she had a particular fondness for felines that she'd never lost. Perhaps it was because they followed their own hearts and listened to no one as well.
As the young man spoke, Eira let her attention be dragged from Rey, though clearly reluctantly. Straightening up from her position, she watched the dark-haired youth stride off to return the book to its previous home. Forbearing to mention that she had wanted that particular book, she lifted one shoulder in a rueful gesture at his departing back and cast her eyes to the girl beside her. "That may have been my mistake, really," she confided, speaking conversationally to her but with a tone that was just loud enough for the young man to hear if he particularly cared. "I was expecting books with enchantments placed by original owners themselves, but they did warn me that the students at this school were fond of... ah, pranks, to put it politely. I won't make the same mistake again." There was a cheery sort of ruefulness in her voice, enhanced by the insouciant expression on her face. "Speaking of students, you two must be the only two I've seen in here all day. I'm surprised you both aren't outside enjoying the weather." The words weren't particularly inflected either way - it could be either a statement or a question, depending on how one chose to take it, and therefore let them both decide how they would answer, if at all.
[ooc: I'm not really sure where else to go from here with Eira, so I left it open in case you guys want to move on past her and I can bop back out if you want]