Trivia: In the beginning of the episode, the courier carries a bag bearing the logo of the "World Tolerance Initiative", alluding to the next episode, "The Bishop Revival."
Trivia: The glyph code for this episode is WINDOW.
Trivia: The Observer can be seen walking behind the CDC director as he tells an assistant to call the State Department.
Science Center Worker: May I help you?
Astrid: Yes, uh, I'm looking for someone who seems to have gotten lost.
Science Center Worker: Okay, what school is he from?
Astrid: He's not from any school. He's a man. His name is Dr. Walter Bishop.
Science Center Worker: Hmm, I see. A special needs individual.
Astrid: Heh, you have no idea.
Walter: When the Victoria, the last surviving ship, return to its harbor of departure after the first circumnavigation of the earth, only 18 of the original 237 men were on board.
Small Child: What happened to them?
Walter: They all died, young lady. Horrible and most likely painful death. You see, when you open new doors, there is a price to pay. Now imagine... tonight, you look under your bed, and, lo and behold, you find a monster! And you're immediately eaten. Now, if you hadn't looked for the monster, you wouldn't have found it and you'd still be happy in your beds, instead of being slowly digested in the stomach sack of the creature. But, with any luck, your sister or your brothers might have heard your screams, and your endeavor will serve as a valuable lesson to them.
Walter: Take me to your centrifuge.
Peter: I'm sorry.
Olivia: You weren't yourself.
Peter: It's lucky for me that you were.
Astrid: Walter. Um… inside… upstairs… when you said, "I can't let Peter die again…" what did you mean by that?
Walter: Some things are meant to be left alone, Agent Farnsworth.
Latin America: March 9, 2010 on Warner Channel
Australia: March 10, 2010 on GO!
UK: March 16, 2010 on Sky1
Germany: August 16, 2010 on ProSieben
Poland: December 2, 2010 on TVN
Finland: December 15, 2010 on MTV3
Czech Republic: January 28, 2011 on Nova Cinema
Slovakia: June 4, 2012 on Markiza
Blair Brown is credited but doesn't appear.
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