On the Other Side, Olivia meets with Brandon, who reviews her physical and mental condition prior to putting her into the isolation tank. Secretary Bishop arrives and makes sure that she's up to speed on the fact that her "counterpart" can safely travel between dimensions. He insists that they need her to develop the same ability so that they can take the battle to the ones who "attacked" them, but insists that she doesn't have to do it if she doesn't want to. Olivia agrees, but secretly takes anti-hallucinogenic medication afterward. Despite that, Peter "appears" and warns her that she can't block him out. He asks why she agreed, but Olivia ignores him, so he figures that she agreed so that she could fit in. However, Peter warns her that she can't get rid of him with medications.
At the Franklin Street Station in Brooklyn, Matthew Rose and Mark Wilner work on a quarantine zone, cutting a man out of the massive block of amber. They finally get the man free and then resuscitate him. It's Matthew's twin brother, Joshua. Some of the amber mist is released and Wilner is caught as it starts to solidify. Matthew briefly tries to free him but is forced to abandon him and get Joshua to safety.
Later, Lincoln and Charlie are called to the scene and quickly realize that the men involved weren't looters. Olivia arrives late from her medical exam and they bring her up to speed. Charlie notices something wrong and accesses a video file on the dimensional incursions, and the amber 31422 substance used to quarantine the breaches. There's a scene from the station, and Charlie uses it to confirm that Wilner wasn't there before. They examine the discarded scraps of amber and find one with an impression of Joshua's face.
Secretary Bishop is drinking at a bar and looking at clipping about his son's disappearance. Colonel Broyles finds him there, and Bishop talks about how he developed amber 31422. He regrets all of the people in quarantine zones that they had to leave imprisoned. Broyles assures him that it was necessary, and the people understand. However, Bishop explains that the truth is that the people in the amber can theoretically be freed and resuscitated, just like the man at the station. However, doing so could weaken the amber and break the quarantine. The people who had lost loved ones could insist on breaking the quarantine, and riot if they're ignored. Broyles assures him that they'll find the men responsible before they spread world to the public. Bishop then tells Broyles that Olivia has agreed to participate in the experiment, and assures the colonel that he'll do whatever he has to, to repair the imbalance between the two worlds.
At Fringe Division, Olivia and Charlie watches as Lincoln makes a plaster cast of Joshua's face. They put it through facial recognition and confirm that he was a bank robber that built a device that let him walk through walls and rob banks. Wilner was a thief that worked with him. Each time he did, it caused a dimensional breach, and people in the area had to be sealed in amber 31422. Joshua was caught in the amber during his last robbery, four years ago. Broyles tells them about how someone in amber can be resuscitated, and swears his team to secrecy. He then tells them to go to Joshua's apartment, which has been sealed since his imprisonment, and look for clues.
At the Rose home in Manuet, NY, Matthew tends to Joshua as he recovers. Matthew's wife Danielle comes in, but is clearly upset when Matthew talks to her. She angrily walks out of the room.
The Fringe team goes to Joshua's apartment and starts searching. Peter appears to Olivia as she finds Joshua's plans for his vault-penetrating device and comments that they look familiar to her. Olivia tries to ignore him, while Lincoln checks their information on Joshua and confirms that he had a brother named Matthew. Matthew works as an accountant and helped the authorities when they tried to track down Joshua. Charlie finds a hidden room containing high-tech equipment which Lincoln identifies as the components for a negative-matter ring. Also present are canisters of ferrocene gas, which is necessary for the device. Olivia hears something and tells the others to stop moving, and then tells them to get out. They run outside just as a bomb explodes.
The team goes back to Fringe Division for medical treatment for their minor injuries. Broyles visits them and congratulates Olivia on saving everyone's lives. One of the nurses leaves Olivia in a cubicle and goes to get bandages, and Olivia steals some more anti-hallucinogenics from a cabinet. Lincoln comes in and invites her to go with him to talk to Matthew, and Olivia hides the rugs and goes with him.
Olivia and Lincoln go to the Rose home and talk to Matthew, who is watching his two young sons play. When they ask if Joshua would come there if he was free, Matthew insists that he hates his brother because he ruined their family after robbing the banks and putting hundreds of people in quarantine as a byproduct. Convinced, the agents leave and Olivia gets a text message from Brandon saying that they're ready for her. When Lincoln offers to go with her, she insists that she can handle it.
At the Rose house, Matthew goes to the room and finds Joshua. However, he quickly reveals that he is Joshua, and the brother trapped in the amber was Matthew, who went to the bank four years ago to try and stop his brother, and was caught in the amber. Joshua vowed to free his brother, and was finally able to do it. Danielle comes in and kisses her husband, Matthew.
Olivia arrives at the DOD lab and Bishop explains that since she has the same genetic structure as her counterpart, she should be able to transition between dimensions. They put her in a sensory deprivation tank filled with water and then administer psychotropic drugs in the hopes that it will trigger a reaction. Brandon and Bishop watch for four hours but nothing happens. Bishop increases the drug dosage and there's a sudden reaction from Olivia. The cameras inside the tank blank out... and Olivia finds herself standing in a souvenir shop on Liberty Island on This Side. A young boy witnesses her arrival, but looks away for a moment when his mother comes over. When he looks back, Olivia has disappeared.
Back on the Other Side, Olivia reappears in the tank, and Brandon and Bishop get her out. They realize that she's successfully transitioned from dimension to dimension.
Later, Olivia is at home reviewing the file on the man they believe is Joshua Rose. Peter appears and warns her that Bishop needs her to believe she's her Other Side counterpart so that he can convince her to demonstrate her abilities for him. Olivia ignores him and takes more drugs, and then answers the door. It's her mother, Marilyn, who says she's there for their traditional Tuesday lunch. Olivia apologizes for forgetting, and Marilyn asks if she's okay. Olivia insists that she's tired and starts to explain that she's seeing things. However, Peter interrupts to tell her that he went to school with twins, and they both got As despite the fact that only one did the work. Realizing what Peter is telling her, Olivia apologizes to Marilyn leaves.
At Fringe Division, Olivia explains to Broyles that Joshua posed as Matthew, and Matthew was the one trapped in amber. They bring "Matthew" in, but the identification systems confirm that he is who he claims. When Olivia interrogates him, he's able to tell her what they discussed earlier at the house. Olivia insists to Lincoln and Broyles that the twins have switched again and are now who they really are. She figures that Joshua told Matthew what he said to the agents in anticipation of Olivia talking to Matthew. Broyles takes her outside and warns that he can't hold Matthew on Olivia's hunch. Angry, she walks away, while Broyles receives a visitor: Marilyn, who warns the colonel that her daughter hasn't been acting like herself recently.
Olivia wonders if Lincoln believes her, and he tells her that he's checked and discovered that someone has stolen three canister of ferrocene gas. He informs Broyles, who sends Charlie and Lincoln to investigate while telling Olivia that she's off the case and should get the rest.
As he walks down the street, Matthew calls his brother and warns him about Olivia's suspicions. Joshua tells Matthew to stay away from the house while he comes up with a plan. Danielle confronts him and Joshua admits that he didn't think the authorities would see through the deception. Danielle informs her brother-in-law that Matthew's mind was frozen at the same time as his body, and he lived for four years with the thought of what would happen to his wife and sons. Joshua insists that he has a plan, but Danielle tells him that the only thing he can do is turn himself in to the authorities, because he's already done enough damage to the family. Danielle leaves and Joshua looks outside at the boys.
Olivia goes to see Agent Farnsworth and has her calculate where Joshua will strike based on his behavior patterns. Farnsworth comes up with a huge list of banks, but Olivia realizes that when she talked to Joshua, he was ashamed. She doesn't believe that he would endanger anyone again, and has Farnsworth narrow the possibilities down to three banks in lightly populated areas.
Joshua goes to the Riverdale Bank and sets up the negative-matter ring in the subway tunnel next to the vault. Olivia arrives and Joshua manages to stun her unconscious.
The technicians at Fringe Division detect a dimensional breach, and Farnsworth determines that it's Joshua's equipment again. Broyles starts to leave with his team, and Farnsworth notes that Olivia was right... cueing him in that Olivia is already there.
Matthew arrives and finds the unconscious Olivia, and his brother's negative-matter rings.
Outside, the Fringe team arrives and realizes that Olivia is somewhere nearby. As the team plants amber release tubes, Charlie Lincoln ask Broyles for five minutes to find Olivia before they initiate quarantine protocols and trap her in amber. Broyles reluctantly agrees despite the risk. They go in and find Olivia as she wakes up, and get her out.
Matthew enters the vault and tells Joshua that he knows what he's up to: his brother doesn't plan to leave. Joshua explains that if he's caught, the authorities will realize that Matthew was the one trapped in amber, and will hold him for experimentation. He sets off the laser beam, bringing down a gate that separates them. Amber start to flood the chamber, and Joshua tells Matthew to get out before it's too late. Matthew reluctantly flees while Joshua is trapped in amber.
Outside, the techs confirm that Joshua was the only casualty. Broyles dresses Olivia down for disobeying protocol... and then congratulates her on her efforts. However, he studies her suspiciously as she goes.
Later, Olivia goes back to Matthew's home and expresses her condolences on Joshua's entrapment. However, after she shakes hands with him, Olivia reveals that she just obtained a skin sample, and they can use it to determine if he was the one in amber. Matthew's son comes up, and Olivia considers him for a moment. She then tells Matthew that the investigation is officially closed and wishes him luck.
As Olivia gets in her car, Peter appears to her today and points out that she let Matthew go because he's just as trapped as she is. She continues to ignore him and Peter asks why, and she finally insists that he can't prove what he's saying. Peter explains that as a manifestation of her subconscious, he knows all the things she knows. He tells her about her life on This Side, including the fact that she has a niece and it's her birthday. When Olivia wonders how he can prove what he's saying, Peter says he has a way.
Olivia returns to the DOD lab and insists on another round of tests. As she spends more time in the sensory deprivation tank, Bishop and Brandon realize there's a chemical in her brain, present from an early age, which lets her travel between worlds. Olivia has another seizure and appears in the same souvenir shop as before. She picks up a postcard commemorating the fall of the two towers, and then calls her Ella, her niece. Ella is glad that her aunt didn't forget her birthday. Olivia fades out and finds herself back at the Other Side, and tells Bishop and Brandon that she didn't travel to another dimension. Share this article with your friends