Given that both Patty and her half-brother are pirates, it can be reasoned that this quest belongs to the Voodoo Pirates faction. However, this quest is given to every player, regardless of eventual faction, and cannot be missed. Therefore, it is more accurate to say that no specific faction assigns this quest.
After his nightmare at the beginning of the game, the Son of Steelbeard equips himself and prepares to make landfall on the Crab Coast. After he goes ashore with his half-sister Patty, the quest is automatically added to your quest log once you start up the trail running along the small stream.
Following is the only way to complete this quest. After proceeding to the temple and managing to find an alternate route inside, the quest is marked as complete once you reach the first room where a dead pirate lies. Because this path is necessary to continue forward in the game, completion of this quest is also automatic, and there is no alternate method for completing it.