Collect the Golden Octopi. Walk over to the Quarters.
Collect the uniform . Use the blade on the sea horse , to obtain the green eye. Also, collect the octopus.
Return to Prison. Give the uniform to the fisherman.
Objective completed: Provide fisherman with a uniform.
Put the green eye into the sarcophagus  and collect the Golden Fish from there. Approach the skeleton  and complete the HOP. You will receive gold insignia.
Return to the Yard. Talk to the fisherman  and watch him act. Then, after a short cutscene, talk to him again. Walk over to the Embankment and collect the chest panel. Use the gold insignia w  (Chapter 7: The Carriage).
Search through the locker and collect the elevator emblem. Then, approach the door  and use the emblem to open the elevator and enter it.
Objective completed: Get to the siren!
Collect the (treasure key).
Return to the Yard, approach the door over the stairs to the left, and open it with the key that you have just obtained. Enter the Treasury (Chapter 7: The Treasury). Collect the Brass idol.
After the cutscene, talk to the fisherman , and block the door out .
Return to the kitchen and activate the HOP in . You will receive meat. Put the Brass idol next to the other ones  and collect the Golden Fish.
Return to the Apartment. Talk to Calliope.
Objective completed: Find a way to stop the kraken
New objective: Restore Calliope's power
Approach the table  and collect the lever from it. Collect the fire poker from the fireplace. Approach  and use the (lever), then, pull it. Go up the stairs to the Gong.