Fishery Service Agent Jackie Quiñones is off the wagon and off the force in the final season of Hightown, but that doesn't stop her from careening into the dark underbelly of picture-perfect Cape Cod to save a missing woman and a murdered sex worker. Meanwhile, her former colleagues Ray Abruzzo and Alan Santille are focused on taking down drug syndicates, but despite their best efforts, the drugs keep flowing. This attracts Shane Frawley, a gangster from Boston looking to cut himself in on the Cape's drug trade - and making an enemy of Osito while he's at it. Alliances are made and old loyalties are questioned in this beautiful but corrupt place where nothing is as it seems.