Extremely popular module because of the treasure, but it's also very fun. If your players are dense, emphasize that each clue is pointing them to another location, show them on the map if they still don't get it.

A small comment about the final encounter: it specifies that the final boss does not attack until all the papers are lit (10 rounds), I do not recommend sticking to this as it makes it too easy. Have him use his battlefield control spells if the players try attacking him.