Dexter: I was drawn to science out of curiosity. Any questions I had, the answers were already there, but even science is never certain, even the soundest of theories is subject to new data. And there are some things even science can't explain. Brother Sam would say it's not an accident that I've stumbled onto a killer that seems to have his own kind of faith. And while I don't believe in an unseen hand creating his own tableau, I do believe I don't have all the answers.

Dexter: I will not kill my sister. I will not kill my sister. I will not kill my sister.

Dexter: I'm Dexter, and I'm not sure what I am.
Everyone: Hi, Dexter.
Dexter: I just know there's something dark in me. I hide it. Certainly don't talk about it. But it's there. Always. This ... Dark Passenger. How when he's driving, I feel ... alive. Half-sick with the thrill, complete wrongness. I don't fight him. I don't want to. He's all I've got. Nothing else could love me, not even ... especially not me. Or is that just a lie the Dark Passenger tells me? Because, lately, there are these moments that I feel connected to something else. Someone. It's like ... the mask is slipping, and things, people, that never mattered before, are suddenly starting to matter. It scares the hell out of me.

Dexter: I'm drifting. I finally get a chance to kill and I can't do it. I get a second chance and he gets away. And now all my secrets are floating to the surface. Where is the orderly controlled effective Dexter? Where did I lose him? How do I find him again? I'm drifting. But not to sleep.

Dexter: I'm going to take this gag out of your mouth; but if you make one sound I don't like I'm gonna cut your eyes out. Blink so I know you understand. [Cole blinks, so Dexter removes the gag]. We know about Boyd, and Dan the Dentist, and now you. Who were the others?
Lumen: The guy who held a watch up to my ear? "Tick, tick, tick, that's the sound of your life running out."
Cole: [smirks, but doesn't say anything]
Dexter: [holds a knife to Cole's throat] What are their names?
Cole: [whispers something]
Lumen: What did he say?
Cole: [defiantly] Huey, Dewey, and Louie.
Dexter: [Regags him, and then turns his head to the pictures of his victims] Look at the women, whose lives you destroyed. [Forces Cole's eyes open] Look. Death was the only kindness you showed them. [Dexter slices Cole's cheek and takes a sample of his blood, as Lumen watches with a mixture of fascination and horror. Picks up his knife] It's a shame that you can only die once. [He then looks at Lumen, who nods in approval. Dexter then stabs Cole in the heart. After a long pause] You said I've done this before, that's true. This is who I am. When I was a child my mother was murdered in front of me. It shattered me. I've done this ever since. Because, for the longest time it was the only way that I could feel ... unbroken. And then, Rita was killed, and none of this made sense any more. [Long pause] Until now. [He picks up the blood slide and holds it out to her]
Dexter: [voiceover] Miguel couldn't, my father couldn't, can anyone live with the truth of what I am? [Lumen takes the blood slide] Is Lumen what will make me whole?
[LaGuerta is blaming Debra, instead of herself, for the shootout at the club]

Dexter: I'm going to tell you something that I've never told anyone before.
Dr. Emmett Meridian: Okay.
Dexter: I'm a serial killer. [pause] Oh God. That feels ... so amazing to say out loud.
Dr. Emmett Meridian: Well, you must be letting go, 'cause I've never heard you make a joke before.
Dexter: I'm not joking; I kill people. Whoo. There it is again. [pause] You should try it. I know -- your big bad wolf has racked up a tidy little death toll.

Dexter: I'm just not used to checking the fridge for notes. [voiceover]... just notes from other serial killers.

Dexter: I'm on edge. Thirty-eight days, sixteen hours, and twelve minutes have passed since I killed my brother. In that entire time, I haven't had a single night to myself. Sergeant Doakes makes sure of that. He follows me everywhere now. A human bloodhound incited by the scent of darkness. My best hope of losing him is to act relentlessly normal. Dull. So I bowl. What's really disturbing is that I'm good at it.

Dexter: I'm sure Special Ops taught you to rattle your captor, but I should warn you, Sergeant. You can't play on my feelings. I don't have any.
Doakes: Oh, really. Who's lying now?

Dexter: I've learned that periods of darkness can overcome us at any time. But I've also found that I'm able to endure, overcome, and in the process grown stronger. Smarter. Better. All is well in my little corner of the world.

Dexter: I've lived in darkness a long time. Over the years my eyes adjusted until the dark became my world and I could see.

Dexter: I've never had much use for the concept of Hell, but if Hell exists, I'm in it. The same images running through my head over and over. I was there. I saw my mother's death. A buried memory forgotten all these years. It climbed inside me that day, and it's been with me every since. My Dark Passenger.

Dexter: If I can get the crotchety, judgemental babysitter from Ireland to trust me, why not you?

Dexter: If I do this, I need a day to get my affairs in order.
Doakes: That's fine. Tie me up, throw me in the trunk, come on, let's go.

Dexter: In the long run it would be easier on Deb. Rita. Better than watching me dragged in like an animal. Which, let's face it, will happen. Some day.