Walter is appalled at the implied suggestion, but Astrid needs it spelled out for her: Peter's talking about shutting down the bridge, to break the connection between our Cortexiphan kids and their Earth-2 doppelgangers. Astrid asks if that would work. "In theory, yes," says Walter, which is hilarious because it's been all of about fifteen seconds since he said it's possible that the link is what's allowing this to transpire and now he's apparently going with the assumption that it is and is making further assumptions about what would happen if the bridge were to shut down.
Walter says if they shut the bridge down they won't be able to start it back up again. You know, until later when it becomes convenient plot-wise to do so and Walter figures out a way that's so crazy it just might work. I mean, why couldn't the turn the machine back on? Oh and Walter also says the healing that the other world is experience will likely stop. Things won't get any worse, but they won't get any better anymore. Why? Because shut up, that's why, apparently.
Olivia's got another idea: find Jones and stop the attack and they can keep the bridge open. To that end, they bring a very unsettled-looking Nick Lane from the other side and seconds later in TV time he's in the Harvard lab with a Walter Bishop head apparatus on and an IV drip. "Will any of this stuff hurt me?" he says and Walter -- rather unconvincingly -- is all, "Shouldn't!"
Olivia explains to him that she knew this universe's Nick Lane when they were kids and she's hoping to use his psychic connection to his doppelganger to find him and exploit the childhood bond they used to share. Earth-2 Nick is a little raised-eyebrow over this making sense to all the rest of them and Lincoln advises that he basically shut up and go with it.
Olivia decides to go stand over by Fauxlivia and be awkward, while Fauxlivia tells her how boss it is that they're working hard to try to prevent the bridge from shutting down. Olivia makes a "who farted?" face at Fauxlivia, who keeps on trying to be nice to her. Or at least trying to guilt her into having a conversation by giving a long rambling speech about how the air on Earth-2 is so fucked up that they don't get rainbows when it rains anymore. But since the healing has begun, she's started to hope that people there will start to see rainbows again after 20 years. "I still find myself looking up after it rains," she says.
So they're ready to go, but not before Walter has one final question for Nick: has he ever tried LSD? Because it's Walter, he asks the question after he already stuck some in Nick's mouth.