There's a certain trend that seems to accompany people who are brought here. A sort of magnet effect, you could call it. When people from the same world arrive, it tends to be people who know each other, ones they're somehow closely entangled with. There's also a snowballing effect in corollary — the higher the concentration of people from a given world, the faster they seem to be brought here.

[She doesn't take her eyes off the chalk. Not yet.]

I've never been magnetic enough for it, myself. But I've known people who have.

[And now at last she glances at him, quiet.]

If there's four of you here already, you stand a good chance of seeing more of them again, too.