Arthur walks back in from the van, just in time to see the semi-circle, Suzy starting to look scared, and... they're gone?

His mind races in circles, Suze! What the hell? They just...vanished? Am I nuts? Suze!. This might have gone on for a while, but he's then he's jostled by a girl walking backwards.

He blinks, then turns a bit toward her. "You see what I just saw?", he says, in a shocked, slightly hollow voice.