Runescape quest help, "Icthlarin's Little Helper"?

When you first start the quest and the Wanderer first teles you into Sopheam, what happens if you leave the city? How do you get back into Sopheam and the pyramid? Also, the Priests won't let me into the gates, they just say "Sopheam is under quarentine, no one may leave or enter the city". Is there another way in?