Now that Trinity has discovered Dexter's true identity, the serial killer warns Dexter to back off. But Dexter will stop at nothing to get rid of Trinity on his own terms, even if it means putting himself on the wrong side of the law. Ultimately, the two end up in a confrontation that will change their lives forever. Meanwhile, Rita takes note of her less than perfect relationship with Dexter, but reaffirms her support.
Dexter Takes a Joy Ride
The action picks up where we left off: with Dexter and Trinity face-to-face at the Miami Metro station following Trinity's discovery of Dexter's true identity. "He knows my name, occupation, he can find out about my family...my family. What the hell have I done?" Dexter says to himself.
Trinity tells Dexter that all he wants is for Dexter to disappear from his life and he'll do the same for him. "If I were you, I'd give up vigilantism. You're not very good at this," Trinity tells him before walking away with a smirk on his face. But Dexter is not going to wait another second. He pulls out a syringe from the back of a drawer and runs out to follow Trinity. Of course, Quinn gets in his way, but Dexter literally throws him to the ground and speeds off to catch up to Trinity.
Dexter begins to weave in and out of traffic like a mad man while talking to Rita on his cell. In the process, he takes out someone's driver-side mirror, but doesn't think twice about it. Dexter finally catches up and finds Trinity pulling into a bank parking garage. Dexter hides, and when Trinity returns, he injects him with the syringe. He throws the body into the van and opens Trinity's envelope to find a boat-load of cash. Arthur cleaned out all of his bank accounts. Dexter thinks luck is finally on his side because now everyone will think Trinity skipped the country. But as soon as Dexter opens the door, he sees the man whose car he side-swiped talking to the cops by his car. Uh-oh. Dex quickly hides the cash and heads toward them to face the music. He tells the cops he was speeding to get to a crime scene in the hope that his fellow cops will let it slide, but they're not having it. Dexter lets his anger start to show and he winds up behind bars.
Harry appears to tell Dexter the reason he is behind bars is because his family is keeping him from thinking clearly. Rita shows up, and Dex is at a loss for words when he tries to explain his recent behavior. He tells her a "darkness creeps in and takes over," but she tries to support him. She drops him off at his car, and as soon as she leaves, Dexter sprints to Trinity's van.. But Trinity is gone.
Deb's Disturbing Discovery
Deb is still pushing hard on the Trinity case, but Batista tells her to take a day off to regroup following Christine's suicide. So, she calls Valerie, her dad's C.I. mistress. Deb asks Valerie to take her to the house of the other C.I. Harry left Valerie for. As soon as they arrive at the house, Deb's mouth drops. It's the same home the Ice Truck Killer took her to when he tried to kill Deb. Valerie says the woman's name was Laura Moser (Dexter's mom) and she had two little boys.
After looking up the details of Laura Moser and her murder, Deb discovers she had two sons: Brian and Dexter. Immediately Deb makes the connection and asks to talk to the Deputy Chief about the quadruple homicide in the ship yard. She asks him if Laura Moser was Dexter's birth mother, and the Chief admits that Harry adopted Dexter. He also tells Deb, who's absolutely shocked, to just keep it to herself.
The Team Catches On
The team can't seem to find anything other than the Dexter's planted DNA that would lead them to believe Beaudry is the Trinity killer. After discovering some of Christine's postcards weren't listed in Lundy's research, they do some more digging. They soon make the realization that 10-year-old boys were also a part of Trinity's pattern.
They bring in the little boy who Trinity recently abducted to see if he can remember anything about his kidnapper. The little boy says he remembers seeing papers in the van with a picture on them. He recreates the "Four Walls" symbol, and the team sets out to one of the build sites. There they discover the body of a 10-year-old boy in a bag buried under the patio.
Trinity Makes a Pit Stop
While his family is sitting down to dinner, Trinity storms in and demands everyone collect their items of value and give them to him immediately. Jonah questions his dad and talks back, but Trinity pins him and threatens them.
Trinity goes on his computer and looks up Dexter's address. He heads over, but the address is Dexter's old apartment where Deb now lives. And he's not very happy that he got it wrong.
Dexter Thinks Fast
After a heart-to-heart with Rita where Dexter discovers he can "conquer whatever darkness is in him," Dex convinces her to go to the Florida Keys where he'll meet her later the next night. They send the kids off to Disney World with their grandparents, and as soon as Rita and Harrison are safely in a cab headed for the airport, Dexter sets out to find Trinity.
He goes to Trinity's home and asks the family if they have any clue where he is. But moments later, Dexter hears a helicopter and sees the S.W.A.T. team surrounding the house. He immediately hides in Trinity's coffin inside the garage and waits a few minutes. He jumps out in the nick of time and puts on his badge as the garage door opens to reveal Deb and Batista standing there. Though Dexter tries to play it all off, Deb seems to look at him a bit differently now that she knows the truth about her brother. Well, sort of.
Dexter watches as Trinity's family is escorted to the police car in tears and visualizes Rita and the kids. Harry, the cop in his vision, tells Dexter this will be his family's future unless he leaves them. Dexter actually seems to want to take his dad's advice this time. But then Deb pulls Dexter aside to tell him what she discovered about Dexter's real mother and brother. Dexter plays dumb and tells Deb her involvement with the Ice Truck Killer is all his fault. But Deb, holding back tears, tells Dexter that he's been the only constant good thing in her life. Dexter second-guesses Harry's advice thinking he is good for his family.
Dexter sees the smashed windshield of Jonah's mustang in the garage and knows Trinity must have went to the auto body shop. After Trinity picks up his newly painted black mustang, he drives off thinking he's going to get away. At nightfall, however, Trinity pulls over after some car trouble. Dexter sneaks up behind Trinity and tosses the missing oil cap from the car after knocking Trinity out.
Trinity wakes on Dexter's kill table, surrounded by dozens of photos. Trinity tells Dexter he never took pride in his killings like Dexter does. But Dexter says Trinity is the worst of the two because he destroyed his family and Dexter is nothing like that. "You can't control the demon inside you any more than I can control mine," Trinity tells Dexter. Trinity says he tried and prayed for a way, but it was inevitable. Dexter refuses to believe anything is inevitable, despite Trinity going on and on about "fate" and "God's plan." For a moment, Dexter seems to show sympathy by turning on the toy train and playing Vera's song for Trinity. And at long last, Dexter takes the reverse end of the hammer and kills Trinity. "Now it's over," he says.
As he's dumping the body into the ocean, Dexter says to himself that he is going to embrace his family and not let the dark passenger take him all for himself. "It all begins with a getaway. Time away from the old me."
Dexter arrives at his house to pack a few things and head out to meet Rita. But he notices he has a voicemail from her saying she forgot her I.D. and had to come home. Dexter calls Rita, but he hears her phone ringing in the house. Her bag is there. Suddenly, Dexter hears a baby crying upstairs. He runs up and finds Harrison crying and covered in blood on the bathroom floor. He looks over and sees Rita dead in a tub of blood. In a very touching moment, Dexter closes Rita's eyes. Despite his best efforts, Trinity got to Rita.
The image of Harrison crying flashes with baby Dexter in pool of blood in the shipping container. "Born in blood. Both of us," Dexter says as he picks up his son and carries him out. "Harry was right. I thought I could change what I am. Keep my family safe. But it doesn't matter what I do. What I choose. I'm what's wrong. This is fate."
What did you think of the finale? What do you think lies in store for Dexter now that Rita's been murdered? Will all the progress he made as an emotional human being go out the window?