- Dexter Morgan: Speltzer is going to kill again. An alarm is going off inside my lizard brain.
- Debra Morgan: Great, now my brother has a lizard brain.
- Dexter Morgan: The amygdala. The most primitive part of the brain that senses danger. Harry taught me to listen to mine.
- Debra Morgan: Oh, well, you'll excuse me if I don't put my faith in your amygdala.
- Dexter Morgan: But you already have, Deb, dozens of times. All the murderers I've helped you catch, who got brought down because of my hunches. My lizard brain has been your secret weapon all along. You just didn't know it.
- [last lines]
- Dexter Morgan: Deb I'm still your brother. Nothing's changed.
- Debra Morgan: Everything's changed. I don't know if it can ever be the same again.
- Dexter Morgan: [narrating] I'm finally out of my cage. But freedom comes with a cost.
- [first lines]
- Dexter Morgan: [narrating] I feel trapped. Like there's no escape. And it's not because I'm at the Post Office. She's got me penned-in like a caged animal. And an animal is never more dangerous than when it's backed into a corner.
- [he imagines cutting the throat of the Postal employee]
- Dexter Morgan: I thought maybe if I let you in on my process, who'd appreciate some value to what I do.
- Debra Morgan: I don't believe this. You want my approval?
- Dexter Morgan: I want to continue to be honest with you, Deb. But I have to be free to be who I am.
- Debra Morgan: It's a capital offense to be who you are, Dexter!
- Isaak Sirko: My music teacher, Mr, Chillich, he said to me, Issac, you think you're strong, but you are not strong if you don't feel." He gave me an "F", so I pushed him down a flight of stairs. I felt bad about it.