Debra and Dexter in “The Getaway”

Debra

I have something to tell you. And maybe I shouldn't. I don't know.

Dexter

OK.

Debra

I found another CI Dad was sleeping with. A woman named named Laura Moser.

Dexter

[Voiceover] Harry was right. This is it.

Debra

Does that name mean anything to you?

Dexter

Should it?

Debra

It doesn't? Look, she died, but she left behind two little boys. And one of those little boys was you. Laura Moser is your biological mother.

Dexter

[Voiceover] Don't say the rest. Don't know it.

Debra

The other little boy, your brother, was named Brian. Brian Moser - the Ice Truck Killer.