New developments come to light for Peter and his team on Fringe. "Worlds Apart" is the 20th installment of the show's 4th season.
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Fringe Season 4 Episode 20 Quotes

Peter: Walter, could the connection between our two universes be what's facilitating this psychic link?
Walter: I suppose.
Peter: So what if we severed it?

Peter: You did great Walter.
Walter: He can't even stay in the same room as me.
Peter: He listened to you. They all did.