"University? Like, college? The one I know's too little for that." Or way too old, but Kris doesn't know about Flowey, so.

They push off and tail Kris anxiously. Not 'cause they're remotely expecting anything to happen--they're getting restless, and really just want to start a tour of the castle like they usually do for new people.

"The hell's that?" Frisk stops just about at their side, squinting into the dark. "An' why's Papyrus in his room?" They have a brother who's a Papyrus; he's a higher priority than weird appearing shadow doors.