40 Justice is Brined

Where: Nautica, the Courthouse.
What: After Alizarin is defeated and you've completed the main story events in Act II, head back to Nautica. Speak with the Queen to have yourself transformed into a fish. Once you're aquatic, swim down to the deepest parts of the ocean and make your way to the Courthouse.

Where: Nautica, the Courthouse.
What: You'll find a mermaid here who needs your help. She's trying to win a case but is missing crucial legal notes from her mentor. Your task is to retrieve them for her.

Where: The Strand, then sail north to Insula Occidentalis.
What: Use the Zoom spell to travel to The Strand. From there, hop on your boat and sail directly north. You're looking for the island known as Insula Occidentalis.

Where: A cabin on Insula Occidentalis.
What: Once you land on Insula Occidentalis, locate the cabin. Inside this cabin, you'll find a chest containing the mentor's legal notes. Grab them!

Where: Nautica, the Courthouse.
What: With the notes in hand, return to Nautica. Swim back to the Courthouse and speak with the mermaid. Hand over the notes to complete her quest.