It’s been 6 months since LaGuerta’s murder – and Dexter is still managing life as a dad, brother, and serial killer. Debra now works as a PI for a private firm and Batista has replaced her as Lieutenant. Meanwhile, Miami Metro investigates the murder of a man who has had pieces of his brain removed.

Miami Metro continues their hunt for the Brain Surgeon, while Dr. Vogel enlists Dexter to do her bidding based on her own personal experience with her previous patients. Debra continues to track down her PI case and has to take matters into her own hands.

Dexter continues his manhunt for the Brain Surgeon. Dr. Vogel tries to prove to Dexter that he’s perfect as a psychopath. Debra’s PTSD kicks in and she makes a desperate plea to confess to LaGuerta’s murder.

Dexter tracks down another potential serial killer from Dr. Vogel’s list. Quinn celebrates his passing of the Sergeant’s exam by defending Debra’s honor in a fight. Dr. Vogel begins treating Debra for her PTSD.

Dr. Vogel gets abducted by the Brain Surgeon, while Dexter and Debra try and rescue her. Masuka finds out he has a daughter.

Dexter monitors a young psychopath to see if he is suited for his table. Dexter and Debra finally get back to normal, but are surprised by his ex, Hannah.

Dexter enlists Dr. Vogel's help to lure the Brain Surgeon to a location in order to get him on the table. Later, an important person in Dexter's life is murdered before his eyes.

Dexter is torn between fleeing the country with Hannah and Harrison, and taking Saxon out once and for all.