If you have Isabela in your party, you can talk to the three statues standing before a gate in the south-west corner of the dungeons beneath Chateau Haine. They are: Paisley Pete, Knife-Eared Jan, and Left-Hand Rawley. They'll reveal that they are pirates, cursed by their former captain and that only another captain (Isabela) can set them free. In order to do so, you need to reconstruct the Dagger of the Four Winds.
You can find the 4 jewels of the dagger in the various chambers of the Vaults and the dagger in the main room of the vaults through both completed the puzzles and subsequently deactivating the fire.
Once the dagger is complete, return to the statues where you can :
- Allow Isabela to keep the dagger for herself, leaving the three pirates as statues forever (the dagger is restricted to Isabela).
- Make her give up the dagger which will break the curse and free the pirates. When they're free, they will pledge themselves to Isabela. They will also give you a hand in the fight against Cahir in the cave.
If Isabela keeps the dagger:
- 150 XP (quest completion)
Requires: Dual Weapon
Damage: 1.6 + 1.68 * LVL electricity damage
(2.9 + 3.11 * LVL per second)
If Isabela gives up the dagger:
- 300 XP (quest completion)
- The pirates will help in a fight later against Cahir.
- The middle pirate is posing the Captain Morgan leg lift.