At first, Brand's thoughts are for the woman's safety. But there wasn't any reason yet to think that this mission would end in a fight at all, much less one big enough to sweep the locals up into the chaos. There was no need to discourage her from entering the tenement.

But then a though occurred to him, and only years of training and practice in acting for an audience kept his eyes unnarrowed and his body language relaxed. Why demand we get away from her? There were any number of reasons for hostility, but that was an odd request to make. Perhaps she was worried about being mugged, but that was an odd fear to be inspired by a group of corporate-looking types. Perhaps she had an untreated mental illness; possible but statistically unlikely that she would have one that provoked this response. Perhaps she bought that we were property developers, and thought we were intending to take her home, but then why demand we get away from her?

Or perhaps she hadn't bought their disguise at all. Perhaps she was expecting a mysterious group that was after her specifically. Perhaps she was, actually, the Mog that they were looking for, well aware that she was on the run from Forsen, and possibly aware that their own employer was after her as well.

In which case, the main reason she'd be trying to get inside the building would be to retrieve the dagger, and/or other items important for a clean escape.

No proof, not even any evidence yet, just a psychological profile match, but now Brand was on his guard.