You receive a vision of a rooftop "somewhere close by", where a rare moss grows; in the vision, you know the moss is suitable for greatly enhancing the effects of certain types of potions. Now go and find that rooftop. Don't fall off. (Of course, rooftop runners *will* be taken for miscreants by the local City Watch....)
According to the Journals of Lord Goidol, the people of the Southern Cities wear heavy coats all the year round, despite the stifling tropical heat. They claim that to do otherwise angers the gods, and it is true that visitors who refuse to don the local garb are often struck down with a paralytic fever.