Unlock: Liberate the North Krige Crest outpost.
Nina in Gaztown needs some privateers’ blood diamonds to buy passage back home to Samoa. This will involve going to several camps of privateers, most likely murdering them, and taking their diamonds, each of which can be found in an open carrying case. The first group is three riflemen; the second is three riflemen and a sniper.
Deliver the diamonds to Nina and the other shoe promptly drops. Kill her husband, who makes the immediate mistake of turning his back on you, to complete the quest.