I'm doing my first challenge run in The Binding of Isaac and I've decided to do the the first challenge on the list: Dark was the Night. This is the challenge where you automatically have the Curse of Darkness on all floors.
In this run I came across a shop selling the Treasure Map item.
This item "Reveals all rooms for every floor, including the Secret Room. However, it does not reveal icons."(from the wiki)
Which ability has priority? The curse or the map? Will I be able to see the map again? Or will it be a waste of 15 pennys?