- Talk with the vegetable vendors found in the central section of the Cursed Valley of Pali.
- They will tell the descendant to head to the Islet of Zeus where they will need to defeat Sharks to claim a sunken treasure.
- Travel to the Southern region of Kephallonia, south of the Ancient Ruins of Kranioi.
- Make your way to the watery ruins found in this area.
- Once you are close, use Ikaros to survey the area more properly.
- Among the ruins you will find the treasure chest under water.
- What is likely to be reveals is there are 2 sharks circling the Ruins where the chest is.
- The Shark needs to be fairly close to the surface of the water for your arrows to hit it.
- Defeat the 2 sharks before diving the ruins themselves.
- Swim toward the main section of the underwater ruins then dive down.
- Between the Western pillars you can find the location chest.
- Collect the treasure inside it to complete the location objective and this objective of the side quest.