The battle of Sahhur, more generally known as the infamous Massacre at Blood Lake, was among the most brutal battles to take place during the early years of the Great War.
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....)