After the destruction of the council's forces and their hasty retreat from the world's origin, the camp lay in ruins. The smell of smouldering ash filled the air as the sounds of battle were replaced by the soft sounds of the forest. A tattered group of resistance fighters return to the camp and you overhear them talking avidly about their chase after the fleeing council members. The group was split when they were ambushed by a powerful elite in a place where four biomes meet. One recounts how he hid under the water to escape certain death. He thought that he noticed a council member drop a chest nearby during the battle though couldn't be too sure with all the dirt and sand being kicked up.
When you inquire about the location in the story, the scarce details he can recount are:
Start at the camp near 0,0 then travel northeast into the swamp.
Pass a witch hut and continue northeast to find the mouth of a river.
Follow the river and you will reach the place where four biomes meet.