Magic sense, hmm. Well, Emma's eyebrow just rose at that concept, but she didn't exactly question it. Gold could sense magic -she was fairly certain that came from being the Dark One, and she had her own lie detector sense, so maybe he could sense her magic.
"This place definitely has a habit of doing that, giving us a little bit here and there, usually when we're not looking for it." But then, maybe the books were there all along and it just took someone who knew what they were to come and find them. It was an interesting idea, since it might indicate that this place wasn't as random as they thought. Which was actually very scary too.
"Yeah, you know, that might be interesting." And really, if it was something that could help her use her magic, and not just blast at things. Garrett said Dorian knew a little more, right? So maybe Emma would see just what else he knew. "I might end up with more questions than answers though." Since this was basically her first time learning much of this stuff.