This pair of video walkthroughs will teach you how to complete the sidequest 'Finders Keepers' in Dragon Age 2. In it Isabella will call upon you to help her friend, a former raider named Martin. Look at that face in the thumbnail. How could you not help someone so sad-looking?
1. After completing the "Fools Rush In" quest, travel to the Hanged Man. Isabela will tell you about Martin.
2. Find Martin in the back of the Hanged Man.
3. Travel to the Docks during the day and speak to the longshoremen.
4. Find Harbormaster Liam and deal with his assistant Aden. You can bribe or threaten Aden. If you wish to refuse Aden's offer, you can return to the docks at night and steal the Dockside Redirect.
5. Travel to Woodrow's Warehouse and fight the raiders inside. Find the marked treasure chest at the end of the dock to locate Martin's cargo.
6. Return to Martin at the Hanged Man.