A ring of silver enchanted such that if any in the wearer's presence intend to harm them it would grow warm. Unfortunately it's properties are wasted if in place of politics where it is consistently warm.
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....)