Dexter has 46 slides in his slide box, meaning he has killed 46 individuals.

Debra: What's going on in there?
LaGuerta: You tell us.
Debra: Why would I know?
Batista: Come on. You're Lundy's pet.
Debra: Fuck you.
Chico: Seriously, what's Lundy got, or is he just blowing smoke?
Debra: Seriously, I don't know. But if he's got something, it ain't smoke. Lundy's too good to blow smoke.
Batista: Man, no wonder you're his pet.
Debra: Fuck you twice.

Dexter: (to Rita) I feel ... such regret, which is rare for me.

Lundy: What exactly is Sergeant Doakes' problem with you, Morgan?
Dexter: (voiceover) I kill people, for one.

Debra: I wondered if maybe you were also cheesed about my whole not-disclosing thing. I don't want you to think I'm unsure or ... embarrassed or anything.
Lundy: Why would you be embarrassed? I'm hot.

Doakes: Jesus Christ, Morgan. Jesus fuckin' Christ. You're the Bay Harbor Butcher.
Dexter: I really hate that name.
Doakes: Jesus Christ, man.
Dexter: You said that.

In "Waiting to Exhale," Dexter's slide box is half full, but in this episode, the box is completely full. Between these episodes, Dexter killed three people, so his slide box should still have room in it.

Episode Title: Resistance Is Futile

The quote "Resistance is futile" is a popular line from sci-fi movies and television shows.