Trivia: The Observer can be seen behind the ambulance prior to Walter and Astrid being given access to the crime scene.
Trivia: The glyph code for this episode is POWERS.
Walter: May I take a blood sample? The discomfort will only be momentary.
Jessica: That's what all you men say.
Jessica: What are you?
Walter: I'm human. What are you? Is this some sort of alien invasion? Are you part of a strike f...
Jessica: No, I mean--I mean, what are you doing here?
Walter: Despite their itty-bitty size, each of them is capable of storing an enormous amount of energy and it would seem they could be overloaded by the biokinetic energy stored in the cells of anyone infected.
Peter: You mean these people's movement is what's activating the nanites?
Walter: That's what I just said.
Bell: In this game, the skill one must have above all else is patience. The board changes, but very slowly. the art of chess, the art is knowing when a piece is most valuable, and then, in that very moment, being willing to sacrifice it. For in the vacuum created in the loss of what is most precious, opportunity abounds. Influence is maximized, and desire becomes destiny.
Olivia: Walter, you said that you had been having a lot of shock therapy. Do you think perhaps he could have been a hallucination?
Walter: No. No, no. My hallucinations were rarely biped and never men.
Leonard Nimoy is credited as Special Guest Star.
Seth Gabel is credited but doesn't appear.
Canada: May 4, 2012 on Citytv
UK: May 9, 2012 on Sky1
Germany: August 20, 2012 on ProSieben
Finland: April 3, 2013 on MTV3
Peter: It'd be sort of like "don't cross the streams," just, you know, in reverse.