Solitary Island is located southeast of Robinson Island, which you may have visited before when doing Errands and Bounty Hunts. Land on the island and go up to read the monument, which is in Nazcaan script. It reads:
"The secret that the map imparts, lies not without but in its heart."
With no clue as to the whereabouts of the stones, use Travel to go and speak with Kublai again at Skull Mountain. When you get the chance to cast a spell, use Insight and three points will light up on the map. You get the map and your next part of the journey begins.
There are plenty of new Errands and Bounties available, so go to the nearest Swift Solutions and check them out. Make sure you check every city for new pieces of heart, which will help with the Errands. The three locations for the magical stones are Vault of Tears, a ghost ship on the ocean, and The Winter Isles. Start with the Vault of Tears first.
