Isle of Ember
Out at the island, Ciela will notice that the volcano has stopped erupting. She
will then say to go back to Astrid. Now, jump off of the mountain's summit,
then make your way back west and enter Astrid's house. Inside, Astrid will tell
you that you'll need the Spirit of Power, Wisdom, and Courage in order to find
the Ghost Ship. She suggests you go back to the Temple of the Ocean King, and
she also gives you a Power Gem, saying that there are gems for each spirit.
Linebeck will return to his ship, so when you regain control, exit Astrid's
house and go west to your ship. After he blabbers about nonsense, tell him you
want to set sail.
Draw your path back to Mercay Island, all the way to the north.
Head all the way north to the field area of the island, then head northwest and
to the Temple of the Ocean King.