Dexter searches for the next potential killer on Vogel's list, A.J. Yates. He finds evidence that Yates is the Brain Surgeon and tries to kill him, but Yates escapes. Dexter finds out that Vogel is keeping notes on her interaction with him. Miami Metro investigates the murder of one Norma Rivera. Quinn passes the sergeant exam, and Batista presses him to solve the Rivera case if he wants the promotion. Masuka has an awkward encounter with Niki, a 20-year-old, who claims to be his biological daughter via artificial insemination. Vogel begins Debra's treatment, taking her to the shipping container where she killed LaGuerta. Dexter meets his new neighbor, Cassie, who is attracted to mysterious men. Upon learning that Harry committed suicide because of Dexter, Debra tries to kill them both, driving off the road into a lake, then pulling Dexter out.