There are two stories to the Cursed Cup of Immortality, the one that was fabricated and sold to adventurers upon return, and the real story.
Warning: Trickster’s Tankard may result in alcohol abuse, random bar fights and very angry dwarves, half orcs, orcs, giants and anyone else who enjoys their drink.
Use with caution
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....)