Whatever response he had been expecting, that certainly had not been it. For a full human heartbeat following her outburst, all Spock could do was stare in bewilderment after the quickly retreating girl. What had he possibly done to deserve that sort of illogical, emotional response? All he'd done was point out that it was unlikely that every single building was being used for housing and then ask if she had any idea as to which way they should...
Oh.
That was it, right there. In her mind, he'd insulted her then asked for her opinion in virtually the same breath. On Vulcan, of course, any other child would have taken the criticism for what it was worth and continued on with the conversation. However he wasn't on Vulcan and it really was illogical for him to expect a human girl to react as a Vulcan would.
With a soft sigh that was barely audible even to his excellent hearing, Spock began moving in the same direction that she had gone. "Nyota," he called out. "Wait. It would be illo-" Maybe, he thought hastily, he should think of another way to word what he wanted to say.
"I do not believe we should separate," he tried instead, increasing his pace a bit so he didn't lose her as they reached the stairs. "We have no way of knowing what we can expect to find outside." There. That was another valid reason. And he hadn't referred to logic once.
Although now he found himself wondering just how his father managed to do such a thing with such ease whenever having a discussion with his mother. It certainly wasn't easy by any means.