You set out for this cave early in the morning. On the way there you spot a pirate ship out at sea, burning, and goblin tracks leading down and back up. The cave is just a slant between two cracks and illuminated by giant glowing Mushrooms.
A while into the cave, the walls and ceiling turn to stone bricks and the cave appears to be a man-made structure. You get to a large room with 3 doors and a pillar in the center. Searching the southern door you find a barracks currently occupied by Goblins. Some of the goblins attack you but the commander runs away to inform someone of your intruding. After defeating the goblins you chase the last one into a previously locked door. Inside you find more goblins, including the one who ran and a shamen performing some sort of ritual to a shrine. At the base of the shrine is a fountain of blood. After defeating the goblins, you retrieve the necklace that Thomas was talking about.
Upon further search of the cave you find some gold and a strange purple gem. You decide to spend the night outside the cave. Before waking up, 2 pirates try to pilfer the items found in the cave, but are noticed. You start your journey back to town.