Alright, I finished the Acre mission and I assassinated the Doctor character. Then, I talked to my Bureau guy and now, I'm running around the city. I don't know how to get out and go to the next mission. All I see on teh map as objectives are the scholars and the vigilantes. I can't exit the town because it says that I can't access that area yet. The status when I press the start button says "Return to Masyaf and speak with Al Mualim." So, how do I leave this place and get to him?

find the gates mate out of the city walls then follow the path leading out of the city then either ride or jump over to masyaf