Vincent listens as the stranger answers. It does not actually assure him that things are fine, but it does cement the fact that whatever's going on with this person is probably way out of his league of expertise.

"S'that right," he eventually says. He can hear them shuffling closer, but he doesn't actually move his head to look at them. "S'there a lot of you in there?"

That's what Robin told him, anyway. He can't help but sound a little skeptical--but that comes from years and years of living with less-than-healthy people who think all kinds of things about themselves.