Peter knows that he's been sleeping with an imposter. Well, he's not sleeping now. Searching Bolivia's papers, he finds some photo-booth pictures of them looking happy. As he tries to guess a password on her laptop, Bolivia walks in. He pretends it's HIS laptop and claims he's emailing a friend in Greece. He speaks the Greek phrase that Bell had Olivia tell Peter when she returned from the Other Side: "Be a better man than your father."
Bolivia, who doesn't understand him, knows that she just failed a test. She pulls her gun, refuses to answer his questions, and makes him inject himself with a paralyzing drug. It'll wear off in a few hours. She grabs the laptop and leaves.
At the typewriter shop, Bolivia types to Walternate that her cover's blown and requests extraction.
Later that morning, as a medic examines Peter, Broyles says eight weeks, and none of them suspected. Walter figures the call Peter got means Olivia crossed back momentarily. Broyles asks what Peter was doing at Olivia's at 2:15 a.m. He admits they've become more than friends.
On the up side, Bolivia took Peter's computer instead of her own.
While Bolivia waits for Walternate's reply, the shop owner scoffs that they always make you wait. He's been waiting seven years for them to fix his legs, so he can walk without crutches. Bolivia realizes that she took the wrong laptop.
Walternate orders Brandon to bring back Agent Dunham. He says use a narrower harmonic field, focused on Olivia. They'll send her back, since the women have equivalent mass, and they don't need Olivia anymore. Brandon wants to keep parts of Olivia, to study. He would just have to replace their mass.
Colonel Broyles meets with Walternate. Afterward, downstairs, Broyles sees Olivia. She begs him to help her as she's dragged away.
At his Harvard lab, Walter is distraught: There's no way to cross over safely. He's failed them - and Olivia. Broyles says that, so far, they've recovered 17 pieces of Walternate's device. This morning, Bolivia took a small, round piece from the hangar where they're stored. They guess she's completed her mission and is going home. Walter rails against her carnal manipulations of Peter . . . and her pastry manipulations of himself. As Walter munches on a pastry, Astrid notices that the bakery box is from the Bronx. Peter, Walter, and Broyles head out.
Bolivia gets her orders. She leaves a metal box with the shop owner. Shortly later, Peter shows Bolivia's picture to the guy, who claims he's never seen her. But Peter's laptop is on the table. Caught, the owner shows them the special typewriter. Peter rubs off the last message from the ribbon: Penn Station. Newark.
On the Other Side, Col. Broyles visits Olivia's cell. He thanks her for not giving him up. She points to dotted lines drawn on her face and says they're going to send her back . . . after they take out her brain. She explains that there's no war between the universes. She can find a way to let both survive. If you don't trust me, she adds, there's no hope. But he can't. Later, he talks with his wife. He's really struggling with this decision.
As a drugged Olivia lies face down in a surgical bed, Broyles bursts in and shoots Brandon with sedative darts! He bangs a syringe of adrenaline into her chest. Ouch.
They dash to the lab. Olivia sees bags of Cortexiphan, which might help her cross over and stay there. But the tank's been drained. As alarms blare, Olivia says she can use the tank at Walternate's Harvard lab. Broyles will get her there.
At Penn Station, a shapeshifter meets Bolivia. In a restroom, he injects her with the small harmonic rods needed to transfer her back. A woman enters; she knows they're cleaning, but she needs to go. Big mistake. Peter spots Bolivia and the shapeshifter exiting the restroom; they run back in, exchanging fire. Bolivia re-emerges, holding the woman hostage. A girl screams, "Mom!" Standoff. Peter asks the woman her daughter's name. She doesn't know, because she's the shapeshifter! BLAM! He kills it. Bolivia's busted.
Bolivia tries to tell Peter she cared for him. He's not buying. Later, an agent brings him her backpack. Inside is the strip of photo-booth pictures.
At Walternate's lab, Olivia's ready. But Col. Broyles has been tracked, and troops are coming! He says in the end, he has to believe in hope. Olivia sinks into the tank. She closes her eyes . . .
. . . And opens them in Walter's lab. Astrid is stunned as Olivia emerges from the tank. She smiles at Astrid - and collapses.
Outside Penn Station, Bolivia sits in a paddy wagon. Broyles says Olivia's back! Astrid is taking her to Boston General. WHOOM! The wagon shakes. The Bishops open it and recoil. Broyles looks inside - at his double, dead and mutilated. They used him for the transfer in Olivia's place.
At Fringe Division, Lincoln shows Bolivia that he's all healed. It's like nothing ever happened! Yeah, she says, laughing. Then a worried Agent Farnsworth tells them Col. Broyles is missing.
Peter sits beside Olivia's hospital bed. He's sorry; he should have known. She says he's the reason she made it back. He saved her life. Peter kisses her forehead.
The shop owner gets his legs. And the shapeshifter who heals him gets the metal box. Inside is the piece of the device Bolivia took.