Dexter, "Just Let Go" and "Nebraska"

In this episode of "Just Let Go" Dexter's friend Brother Sam, the ex-con turned minister, is shot in his auto shop by a hooded man and ends in the hospital in critical condition. Dexter watches the surveillance video and notices that Brother Sam's dog, who normal barks loudly when he sees someone he doesn't recognize, doesn't budge. Dexter knows that the only other person who can quiet the dog is a kid that Brother Sam decided to take under his wing. Dexter gets a chance to speak to Brother Sam just before Brother Sam dies and he reveals to Brother Sam who shot him. Brother Sam tells Dexter to forgive the kid. Dexter finds the kid and decides to spare his life and tell him that Brother Sam forgives him. Unfortunately, the kid laughs in Dexter's face and taunts Dexter saying that the police won't find out who killed Brother Sam. This angers Dexter which causes him to tackle the kid into the water and drown him in the very same water in which Brother Sam baptised him. The professor and his student continue to carry out their killings inspired by the book of Revelations, but the student begins to have doubts about whether the murders that they are committing are right and he even lets one of the victims go.

In "Nebraska," there is another set of killings that mirror the murders committed by the Trinity Killer, played by John Lithgow, and the Trinity Killer's own wife and daughter happen to be the victims. The department thinks that Trinity is back, but the only problem is that Dexter actually killed Trinity himself. Dexter suspects that Trinity's son is to blame and goes to Nebraska to find him, using the death of Brother Sam as an excuse to take time off from work. Trinity's son lies to Dexter and makes up some bogus story about how he saw his dad kill his mother and sister and how he had to fight his dad off. Dexter tells him that he knows Trinity did not kill them and Trinity's son realizes that Dexter is the one who killed his father and escapes out of the front. Dexter has no choice but to kill him and chases him down. He finally admits to Dexter why he killed his mother and sister and Dexter surprisingly lets him live.

Also, in these episodes, Dexter's brother, Brian, who is dead and was also a serial killer, now appears in Dexter's head and Dexter communicates with him as he does with his dead father. We're are so used to always seeing Dexter talk to his father and after five seasons have gone by, we see it shift to another person, so this adds a very interesting element.