Main Walkthrough

Location: The Hideaway (ship)
Petitioner: Clive's Reading Table
Unlocked: Begin Back to Their Origin and complete A Bone to Pick
Reward: Charred Sparring Sword, Cavall's Fang +1, 30 Renown

There are two prerequisites for completing this side quest:
  • You need to complete A Bone to Pick, a side quest from earlier in the game.
  • You need to progress through Back to Their Origin, one of the final main quests in Final Fantasy XVI. It will have you speak to several NPCs in the Hideaway. Once you're done talking with Jill a bunch of new side quests will pop up.
Check Clive's Reading Table and you've find a missive from Charon. She's again expressing some concern for Torgal, who is troubled about... something. Agree to the quest and you'll find Torgal on the stairs leading from the Rear Stacks to the Atrium, in the north of the Hideaway.

Speak to Torgal and Lady Charon will show up to help interpret Torgal's troubles. Eventually Torgal will stalk away, and you'll need to follow him to the Main Deck. Speak to him again and Clive will somehow puzzle out that Torgal wants to travel to Port Isolde.

Fast Travel to Port Isolde, southwest of Martha's Rest, and check the beach to the north of the Obelisk. There's a shack and a dock on the west side of the beach, and you can board the rowboat at the end of the dock. (If Joshua and / or Jill are in the party, they will opt to remain behind.)
The boat will take you to a tiny island called Mist, where there's a little building called the Rookery (basically a fancy treehouse). Check around for a few Items, then approach the Rookery to trigger a sweet little cut scene. Afterward Torgal will insist on checking beneath a log near the Rookery, and following his lead will trigger another scene. This ends the quest.