Recommended LV: 3
Available after completing “So It begins”
Talk to the civilian couple by the vegetable field west of Mount Ainos in the Cursed Valley of Pali. This is by the main road so it's impossible to miss. Accept the quest then head to the Islet of Zeus to the southeast of the island.
There’s a shark guarding the treasure and it will attack you immediately upon spotting you. Use Ikaros to scout from the sky and to tag the shark.
Now swim towards the sunken temple while the shark is away then quickly stand on one of the pillars above the water then use a Charged Shot from your bow to take out the shark instantly. Retrieve the necklace from the treasure chest (which will also mark this location as “complete”).
Finally, return to the couple and deliver the necklace to complete the quest.