He leaves, and Astrid urges Walter to go talk to Peter, and Walter just stands there looking anguished, and I really hope they make up soon, because this is starting to wear thin for me.
Over at Olivia's apartment, Fauxlivia is watching reruns of Fringe -- specifically, "Dream Logic" -- to help her bone up on Olivia trivia, such as Olivia having a photographic memory: "How am I gonna do that?" she wonders.
There's a knock on the door, so Fauxlivia packs up her Earth-prime orientation package and calmly gets her gun on the side table. She checks the peephole and then points it at the guy who stole the box, standing there in the hall. She orders him into the apartment, telling him not to move unless she tells him to. She tells him to put the box down. He does so, and says, "Please. Don't hurt me, Mrs. Dunham," the voice of someone who's never heard his own voice or anyone else's voice. "You're deaf," says Fauxlivia, figuring it out. "That's why you didn't die."
Back at the lab, Peter's on his cell, saying he'll call Olivia. When he hangs up, Walter wants a moment, and starts haltingly telling him how hard it was to say goodbye to Belly, but it was nothing compared to saying goodbye to his son. Peter had looked open to what Walter was saying, but now he's a little reluctant, saying he's got to call Olivia.
Walter pushes on, choking up as he talks about his own Peter dying, and Elizabeth, and the window in Peter-2's world, and how he always told Belly that they couldn't cross over. "When I saw that you were dying too, and that I was the only one who could save you..." he says, but Peter's still not too impressed: "You kidnapped me, Walter. You took me from my family. From my world." Walter says he didn't plan to, and he's not sure he would do anything differently if he had to do it over again, but at least now he knows that he was wrong TO CROSS THE LINE. Peter still can't talk about it, though, and he walks away.
Over at Olivia's apartment, Fauxlivia is telling Newton that the deaf guy saw her badge outside of Blake's apartment, and he thought he was bringing the box back to the authorities. I realize that this would screw up the plot, but let me just see if I understand this: He wants to bring the box back to the authorities. He sees Fauxlivia's badge when she's at his cousin's apartment, realizes she's the authorities. Instead of bringing her the box then, he writes her name down so he can (fortunately) discover her address and bring her the box later? Yeah, that makes no sense.