Which treasure have the Pogues lost at the start of Outer Banks Season 5?

At the start of Outer Banks Season 5, the Pogues have lost the Blue Crown. The crown is the major treasure pursued through Season 4 and becomes part of the chain of events leading to JJ’s death.

JJ finds the Blue Crown in the Season 4 finale and gives it to Chandler Groff in exchange for Kiara. Groff takes the crown and kills JJ, leaving the Pogues without both their friend and the treasure they had fought to obtain.

The Blue Crown is connected to the legend of Blackbeard in the show’s mythology. Season 5’s announced story says that the Pogues must deal with the loss of the crown while Groff remains at large. Their final mission is therefore about revenge and freedom as well as treasure.