Get the Intrepid Strongbox Key from Captain Halyndor. Use the key to open the Intrepid's Locked Strongbox.
To break the curse and free all of my brethren, the...thing...stowed on my ship must be retrieved and cleansed! I don't know what it was, but I do know that it was stored securely in the ship's strongbox, which Captain Halyndor lorded over.
My old captain is still in my dreams. I know he walks my doomed ship, the Intrepid. Get the key from him, and use it to open the Intrepid's strongbox.
Then, after you have the cursed thing, bring it to the priest Glorin Steelbrow in town.