Walternate seems to accept that reversing years of vortexes and reality-fabric-tears will take more than a few hours (seems like a solid hypothesis), but they don't discuss it too much because Walternate's assistant buzzes in to let him know that Fauxlivia's there to see him. Brandonate's dismissed, and he says hi to Fauxlivia as he leaves.
Walternate's quite happy to see Fauxlivia, although he's disappointed she didn't bring Henry, and his demeanor heads a little farther south when she tells him she's on duty at the moment: "Fringe Division identified a Class 10 energy surge emanating from this complex, which would normally justify evacuating a 10-mile radius around the epicentre," she points out, and Walternate, without explaining what they're doing, says there's no danger to the general public, because they've taken proper precautions. Can Walternate say anything without sounding sinister? Jesus, he's like Hannibal Lecter.
Fauxlivia reminds Walternate that she brought back a piece of tech from the other side that he told her was part of a weapon that could destroy the other side: "Have you activated that weapon? Is that what's causing the surge?" she says. Walter, stony-faced, tells her that's classified. That means yes, obviously, so Fauxlivia asks what's going to happen to the people over there. I hope that's a rhetorical question, because "destroy the other side" seems rather unequivocal.
Walternate, having turned his back to stand in front of the map of the messed-up United States, says his concern is for the people of their world. "But your son is over there," says Fauxlivia, more angry than shocked. Walternate says he's aware of that, and he turns to face her and coldly tells her that Peter chose to leave, and chose his allegiance. "I chose to give up my son so that you could keep yours," he says, unsurprisingly keeping to himself the fact that he needed Henry to activate the machine. Jesus, I know some people don't get along with their in-laws, but I get along great with mine, so I can't imagine ever having to confront my father-in-law over his universe-destroying plans. If I were to do so, I think I'd sit down with him over a few beers first. You're dismissed, Fauxlivia.