Like Karek, I am going to assume that Gandel being the one smart enough to realize we needed to know what was going on outside is also smart enough to tell us all so that Xerissa knows it's show time.
"We gotta move people! Everyone get in close in a huddle, tuck your heads down like you are praying or something. It won't hurt a bit, but it will take a few seconds."
Xerissa gets out her scroll. If everyone assembles, she casts.