The orcs love bloodsports, everyone knows that. If you go deep enough into their lands, you will find their favorite entertainment is the Talbar, the arena.
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....)