Having been caught in the act of eliminating Travis Marshall by his sister Deb, Dexter has to scramble to come up with an explanation. Deb is understandably shaken by what she's just seen but accepts, somewhat reluctantly, Dexter's explanation that he's suffered momentary madness. As she thinks about it, Dexter's explanation makes no sense and decides to dig deeper. Captain LaGuerta meanwhile is puzzled by a piece of evidence she found at the scene of the Marshall killing. When a member of the homicide squad is killed, Dexter goes all out to stop the killer before he leaves the country. Louis Greene starts to meddle with Dexter's computer accounts. Written by garykmcd

With Deb having found all of Dexter's paraphernalia, including the blood slides, he has little choice but to admit everything. She decides not to arrest him or let the police know what he does during his off hours. She does decide she's going to try and cure him and keeps him on a very short leash. Dexter is wondering more and more what to do about Louis Greene who he is convinced sent him the hand from the Ice Truck killer case. Louis doesn't scare easily however. The police continue to press the investigation into Mike Anderson's death not knowing that Dexter has already taken care of the killer. They're raiding the strip club regularly and the owner comes to the US to take care of it personally. Meanwhile, a convicted serial killer offers to tell the police where some of his victims are buried. LaGuerta continues to research the blood slide she found at the site of the Marshall killing. Written by sayemuddin28

With Deb keeping a close eye on him, Dexter is starting to go stir crazy. He desperately wants to satisfy his dark passenger but first decides to get Louis Greene out of his life forever. Deb is growing increasingly frustrated at the lack of progress in finding Mike Anderson's killer. The murderer's employer, Isaak Sirko, is having much better luck and actually traces his former employee right to Dexter's boat. Dexter wants to kill someone and focuses on the recently paroled killer Ray Speltzer. Dexter is convinced that Speltzer will kill again and tries to convince Deb that he can eliminate him before some young woman gets killed. Deb won't hear of it....but begins to question her own moral code when Dexter proves to be correct. Written by garykmcd

The police quickly catch up with Ray Speltzer and they do a brilliant job interrogating him and getting a confession. She and others are shocked however when a judge ruled the arresting officers had violated his Miranda rights and releases him. When he shows up on the sidelines of his latest victim's funeral, Deb goes berserk and decides they have to get him at all costs. Dexter decides it's time for him to do what he does best. Meanwhile, the police are still raiding the strip club and owner Isaak Sirko decides it's time to give the police what they want and frames someone for the hit. Sirko knows that Dexter made the assassin disappear and has every intention of getting even. He has his own special reasons for doing so. Written by garykmcd

Captain LaGuerta confides in Deb that she found a blood slide at the site of the Marshall killing and believes the Bay Harbor butcher is still alive. The Captain accepts Deb's offers to help her in the investigation. When Dexter learns what's going on, he just wants Deb to stay out of it. Dexter finds blood on his boat and tests reveal it belongs to Louis Greene. He soon after finds he has to deal with Isaak Sirko who is clearly out for revenge. Dexter's plan to get him doesn't work out. Hannah McKay meanwhile has agreed to help find some of the bodies from her and her boyfriend's killing spree years ago. The remains of one of the victims tells Dexter a lot about the assailant. Written by garykmcd

Dexter decides he's going to eliminate Hanna McKay and gathers evidence that she has eliminated a number of people in her life. Something unexpected occurs however. LaGuerta begins to think that the Bay Harbor Butcher may have been responsible for the deaths of several criminals who vanished before they could be arrested. After discussing the situation with Nadia, Quinn decides to return the money left in his car. He's given little choice but to help the mobsters: either he eliminates the blood evidence they have linking Isaak Sirko to the Colombian shooting or Nadia will pay the price. A burned out Batista is seriously thinking of retiring and buying a restaurant. Written by garykmcd

Dexter's problems keep mounting. After the surprise outcome of his planned execution of Hannah McKay, they agree they are far too much alike and decide not to see each other again. It doesn't quite work out as planned. Dexter learns that true crime writer Sal Price is writing a book about Hannah as he is convinced she was an active participant in the murders believed to have been committed by her boyfriend. Dexter sets out to get Sal to go in another direction but Hannah takes charge of things. Deb wants Dexter to do what he does best. Meanwhile, Quinn comes under suspicion of having made the blood evidence against Isaak Sirko disappear. Written by garykmcd

Having spent the night together, Hannah and Dexter decide to see each other again. He's not so sure what he's going to do about Deb however. She is adamant that Dexter get rid of Hannah but he refuses, saying he's sure she doesn't want to be responsible for a murder. With everything he has to deal with, Cody and Astor come to stay with him after their grandfather is hospitalized. Deb finally breaks down and tells him her true feelings. Isaak Sirko decides to take a more direct approach and tries to shoot Dexter in broad daylight. Strip club manager George Novikov thinks Isaak has stepped over the line and put their entire operation at risk. He also has the goods on Quinn and starts turning the screws. Captain LaGuerta continues her investigation into Dexter and learns that he moved his boat just as the Bay Harbor butcher investigation was getting under way. Written by garykmcd

Isaak Sirko learns that the Koshka Brotherhood has sent two assassins to Miami to eliminate him. Surprisingly he turns to Dexter with a proposition: help him eliminate the assassins in return for his life. Dexter's not too keen on the proposal and turns him down. Isaak acquires a trump card however: he's taken Hannah hostage and now offers him her life as well. Dexter also has to deal with Deb who is embarrassed by her earlier admission to Dexter that she's in love with him. Hannah meanwhile keeps trying to get Dexter to open up to her. Captain LaGuerta approaches her former boss with her theory about the Bay Harbor Butcher but he blows her off...at first. Written by garykmcd

There is another victim of the phantom arsonist, the fifth in two weeks. Dexter thinks has a pretty good idea who is behind it. He is frustrated because he promised Deb not to interfere in police cases. He tries to explain his dark passenger to Hannah but they're interrupted by a man peeking through the window - who turns out to be Hannah's father who has just been released from prison. He wasn't a very good father - he once left her alone in a motel room for three days while he went off to play poker. He seems to have reformed but after she refuses him a loan he turns particularly nasty. Dexter knows how to make things right. Captain LaGuerta tells her old boss, Tom Matthews, that she suspects Dexter is the Bay Harbor Butcher. When he tells her the Ice Truck Killer was Dexter's brother, she knows she's right, even though Matthews disagrees. Quinn goes after Nadia's boss, George Novikov, when he decides to send her out of State to work in another club. Written by garykmcd

At Deb's request, Batista locates Arlene Schramm, the witness who saw Hannah McKay kill a counselor in a halfway house. When Deb blacks out and has a car accident, she thinks she knows who might have been responsible. Dexter learns that the last of the men who killed his mother, Hector Estrada, is up for parole but has no objection as he has his own plans for the killer. Matthews has a chat with Dexter and tells him of Captain LaGuerta's theory about him being the Bay Harbor Butcher. Dexter is quick on his feet and Matthews believes him when he denies it all. When Estrada tell him that that a female cop pulled strings to get him his parole, Dexter quickly realizes LaGuerta has set him up. Quinn learns that Nadia has skipped town. Written by garykmcd

Dexter visits Hannah in jail to explain why he didn't protect her and she in turn explains why she did what she did. She seems to understand Dexter but has her own plans which don't include prison. Captain LaGuerta disregards the evidence she and Tom Matthews have discovered - and which Dexter planted - which points to Sgt. Doakes as the Bay Harbor Butcher and continues her investigation into Dexter. She arrests him but Dexter has set her up and she is forced to release him leading most at Miami Metro to believe she was trying to frame him. Dexter still wants to get rid of the man who killed his mother but comes to the realization that he will have to deal with LaGuerta even if eliminating her falls outside his code. Written by garykmcd