The Adventures of Atticus King

You unfold the paper. It’s not a note - a map! You can tell that this is a map of the southern Mexican jungle. A huge jungle of wild animals, natives, and secrets. It wasn't just the location that was so curious, but what was drawn on it. Someone used a red pen to circle three points on the map. Interesting.
You have some extra money (not much). You could go see the areas circled on the map, or just ignore it all and keep living in paradise.