Set in beautiful but bleak Cape Cod, "Hightown" follows one woman's journey to sobriety, overshadowed by an unfolding murder investigation. Jackie Quinones (Monica Raymund), a hard-partying National Marine Fisheries Service agent, has her free-wheeling life thrown into disarray when she discovers a body on the beach – another casualty of Cape Cod's opioid epidemic. To deal with the trauma, Jackie takes the first steps toward sobriety-- until she becomes convinced it's up to her to solve the murder.

Now at odds with sergeant Ray Abruzzo, an abrasive but effective member of the Cape Cod Interagency Narcotics Unit, Jackie starts to spiral. And she's not alone – Ray himself crosses more lines than he can count in the name of the investigation. The two of them, along with everyone else connected to the murder, all circle each other, and as their lives crash together, we're reminded just how complicated - and deadly - our addictions can be.