Kaeya, that laugh is music to his ears. The little guy brightens up immediately, and even as the energy around them grows a little more serious, he has the aura of someone eager for the challenge. At his core, that's what got him through some of the worst of it, yanno? The challenge of making things better. (... And the orb's important, too, that's part of the package deal of making things better.)

"You got it, doc. Lunch sounds awesome. I'm starving." He collects his little suitcase (the only thing about him that seems remotely professional, let's be honest), and moves to follow her toward the office doors. "How long have you been at this, yourself? Since the beginning? Because I was gonna ask if there was anything in particular that happened those ten years ago that could've contributed to this sudden mutation.. I mean, when you say 'something happened', do you have an idea of what, or is it a big fat question mark?"

Because pinpointing what happened ten years ago might help them work backwards to find the orb, yeah? You never know. At the very least, even if the orb isn't involved, he can have a starting point in trying to help the people here regain part of their personhood.