If a hero drinks an invisibility potion in a dungeon and it stays to the end after the heroes have left, does the marker remain until the next dungeon/encounter or does it go away at the start of the next game week?

-shnar

its a lingering effect and discarded:

Q: What happens to lingering effects (Bleed, Burn, Curse, Poison, etc.) when an encounter ends?
A: At the end of an encounter or dungeon (but not a dungeon level) all lingering effect tokens are removed from all heroes with the following exceptions: Poison and Curse tokens stay. (Note, however, that Red Scorpion’s healing power means that she will heal all her Poison tokens and then continue to heal until she is at her maximum wounds.)