Trivia: The glyph code for this episode is DEATH.
Trivia: The Observer can be seen in the crowd as Jones passes out the money, walking behind This Side's Lincoln just after he says, "Excuse me, Fringe Division!"
Trivia: The face on the hundred-dollar bills Jones passes out resembles Teddy or Franklin Roosevelt, rather than Benjamin Franklin.
Peter describes amphilicite as "It's not really reactive, like helium..." Helium is an inert, stable, noble gas, the second lightest element after hydrogen. Hydrogen, on the other hand, is a highly reactive element.
Lee: I don't know, I've known Murphy since the Academy. He's always been a straight arrow.
Bolivia: Oh, I just got kind of a hunch that this other Lincoln is telling us the truth.
Lee: Must be because he has such a trustworthy face.
Bolivia: See, I think he's kind of funny-looking.
Lee: You're funny-looking.
Astrid: Walter's just discovered molecular gastronomy.
Walter: I've liquified meat and then placed it in an alginate bath. It's really quite...
Astrid: Quite disgusting.
Walter: That's the thing about scientific inquiry--not every experiment is a success. But I hold high hopes for the Parmesan ice cream.
Lincoln: I need to be a part of this investigation. I lost a partner.
Peter: I lost a universe!
Lincoln: You're scared.
Peter: Yes, I am scared. I'm scared that every day I stay here, the people that I love get farther and farther away from me.
Farnsworth: Are you really from another timeline?
Peter: Yeah, I think so.
Elizabeth: I saw how much you loved him. Your strength...
Walter: Not strength! Hubris. And I've been punished for it ever since.
Elizabeth: By whom?
Walter: By God. By a deity, whatever you want to call it. And I understand, I deserve it. No man should do what I did.
Elizabeth: You made a mistake. That's what being a man is.
Walter: It was more than a mistake. I broke universes. I asked for a sign of forgiveness, but I got nothing. There is no absolution for me.
Elizabeth: Well, I don't believe that. I forgive you, Walter. I forgave you a long time ago. And if I can, God can.
Walter: I lost the people I loved most and I imagine you miss them too, the people you've left behind.
Peter: Yes I do.
Walter: I will help you, Peter. I--I will help you get home. The last 25 years, I've spent thinking about losing my son. I thought I was an expert on loss. Maybe that's why you are here, because there are still things that I need to learn. What?
Peter: I just spent the last several days with the other Walter, and I was very surprised to learn he was not the man that I thought he was. But I am not at all surprised to learn that you are.
Walter: Is that a good thing?
Peter: Yes, Walter. That is a very good thing.
There's a shot of the side of Petronas twin towers with buildings around the area, which are actual buildings from the city of Kuala Lumpur, Malaysia. Followed by stock footage of New Yorkers walking around when it says, Location title: "Midtown Manhatan."
Canada: January 20, 2012 on Citytv
UK: February 15, 2012 on Sky1
Germany: July 16, 2012 on ProSieben
Finland: January 9, 2013 on MTV3