This week picks up exactly where the last episode left off, with Bell showing Walter his overly ambitious science project, plans for a whole new world. Bell has developed quite a God complex over the years. Walter gives him a “they think I’m the crazy one” look and Bell tells him he wouldn’t stop it if he wanted to. Bell thinks it was divine intervention that brought his old friend to him at this special time in his life, when he’s on the verge of destroying two worlds to create his own.
Olivia and Peter arrive at the lab, having just rid the world of David Robert Jones, and they search for Walter. Olivia calls Astrid, but gets her voice mail. They talk about what happened back on the roof, how Olivia pulled punches for Peter. She doesn’t know how she did it, she just did. Peter wants her to allow Walter to run more tests when he gets back, and she agrees. Jessica calls her, sounding frantic. She tells Olivia someone has been following her ever since she left Harvard. Olivia instructs her to lock the doors, she will be right there. As the call ends, we see September in the background, approaching Jessica in her home. After taking a step, however, his feet stick to the floor. There is some type of symbol painted on it, he’s trapped.
Olivia and Peter arrive at Jessica’s place, only to find it empty. Olivia is concerned when they find Jessica’s purse and phone, they fear she was taken against her will. A big chunk of her floor appears to have been taken against it’s will also. The search has to wait, however, because they learn from Broyles that Astrid has been shot, and Walter is missing.
Astrid is in stable condition when they arrive at the hospital. She tells them about the warehouse, and Walter’s theory that Bell is still alive. Someone at the warehouse must have taken Walter. Astrid starts to cry, she tried to protect Walter. Peter assures her that he knows that. He and Olivia go to check the warehouse for clues to Walter’s whereabouts.
Who knew Olivia and Peter were such great multi-taskers? They find the warehouse to investigate Walter’s disappearance, and while there they find September, and by extension Jessica (and her floor). Jessica found a gun, she aims it at them and tells Olivia to drop her weapon if they want to see Walter again. Olivia realizes Jessica works for Bell, and hands over her gun. Jessica tells them how they used September’s interest in Peter’s life to draw him in. She fires her gun at him and he catches all the bullets. It was just a demonstration of his abilities before she brings out the showstopper. She has another weapon, developed by Bell, and it shoots much faster. When she fires at September, he cannot catch it this time, and he is shot. When she fires the weapon at September again, Olivia reaches out to stop the bullet and it ricochets back and hits Jessica. She dies.
Peter finds a way to free September from whatever they had used to trap him on the tiles. Olivia tends to his wounds, and he tells them he doesn’t know where Walter is. Olivia tells him about the day he came to her, and how they now know how he was shot. He doesn’t know what she’s talking about, as the event has not happened for him yet. He will investigate the future and find out what he meant. He leaves, telling them he hopes to get back to them in time. He disappears as sirens are heard approaching. Peter and Olivia make a getaway with the body, however. Just because Jessica is dead doesn’t mean they can’t question her. They get her back to the lab and hook her up to their tech, so they can have one last conversation with her. Nina arrives and leads them through the process, promising if Jessica knows anything about Walter’s whereabouts they will find it.
Olivia questions Nina as to why Bell would be activating her now. Nina says Olivia has always had an enormous capacity for compassion and that was what first led Bell to use her in the cortexiphan trials.
Bell tells Walter that creating a new world was actually his idea, and that when he realized he was smart enough to do it he asked Bell to cut out a part of his brain. They tried to “put the genie back in the bottle.” But then Bell grew older, and developed cancer. He knew cortexiphan could slow it down, but he realized Walter was right about creating a new world. Walter tries to get through to him, but Bell is convinced he is a God and nothing is going to stop him. That’s the thing about crazy people, they don’t realize they are crazy.
Talking to the dead Jessica doesn’t help matters much. Her thoughts are all over the place when they first start questioning her. When they finally get her to talk about Bell, she gives them a cryptic message that seems to suggest he is on a boat. She tells them he is a great man and will give birth to a new world. When she won’t tell them what they want to know Olivia gets frustrated and grabs Jessica. Her cortexiphan super powers seem to send some kind of surge through Jessica’s body and it cuts off the contact, Jessica is now dead, dead. She had been talking about an energy source before she died, and Olivia now realizes that it’s her, she’s the energy source he plans to use to collapse the universes. Nina thinks if Bell is using the energy Olivia is generating, she may be able to find him.
They learn a cargo freighter left the harbor early that morning and fell off the radar a few hours later. Nina explains they can use Olivia’s energy to locate Bell, the frequency should lead them to the place where the two universes are overlapping, the center of the storm, and that’s where he would be. The latest data they are receiving suggests that it has started already, the universes are starting to collapse. Olivia wonders to Peter what Bell has in store for her now. She realizes nothing has changed, she’s still that scared little girl who felt all alone, being used for Bell’s experiments. Peter tells her it’s very different now…she’s not alone any longer.
Walter is still mortified over Bell’s plans. Bell is somewhat frustrated that Walter isn’t sharing his enthusiasm over the birth of a new world. He tells Walter he was right about Olivia, she is a remarkable girl. Outside the ship, they can see the storms brewing. He tells Walter they deserve this, but Walter is still having none of it.
In the Fringe control center, they have data on the center of the brewing storm, and Nina, Peter, and Olivia are on their way. Peter can see the ship as they approach, but Olivia and Nina cannot. They realize the ship is on the other universes frequency, and Peter resonates at that frequency. He thinks they cannot get to it if it’s already on the other side, but Olivia thinks she can do it. Peter can see it, Olivia can reach it, they will need to work together. The helicopter moves in closer so the two can jump. They manage to successfully land on the ship. Now they just have to find the ships resident psychopath. As they pass all the animals, Peter supposes they found his ark.
As Bell recites a poem, Walter removes a gun from a display case. When Olivia and Peter barge in, Bell tells them he hadn’t planned on having humans in his new world, but since they’ve found him they can be the new Adam and Eve. Peter orders him at gunpoint to turn it off, but Bell tells him it is too late. Every breath Olivia takes, every beat of her heart, brings them closer to nirvana. She is the redeemer. While Peter debates whether to kill Bell, Walter takes the gun he is holding and shoots Olivia in the head, killing her and stopping the universe collapse.
Bell tells Walter his action was very clever. He then rings his crossover bell and disappears, lamenting that they could have all been so happy together. Peter is crying over Olivia’s lifeless body, and Walter has to slap him to bring him back into the present. Time is of the essence if they are to save her. Walter moves her to a table, and tries to quickly explain to Peter the regenerative properties of cortexiphan. He has to get the bullet out first, though. Walter works feverishly with what tools he has, telling Olivia how sorry he is as he works. He gets the bullet out, and they watch, seemingly unable to even breathe while they wait. The bullet hole slowly closes. Walter smiles and announces that it worked. Olivia finally starts moving, indicating that she is still alive and on her way back.
Broyles receives word that his team is receiving significant funding to upgrade their operations, Fringe Division is going big. He leaves his meeting a General, no longer a Colonel. He offers Nina a job running their new division, to which she seems very receptive.
At the hospital, Walter tells Peter that after all the energy Olivia expended, her cortexiphan levels must now be almost negligible. She won’t have her super powers any longer, so looks like Peter will have to fight his own fight next time. Astrid, who is now on her feet and walking around, joins them to check on Olivia. She sits with Walter and shares some red licorice with him, and he calls her by her real name. They share a special moment.
Peter excitedly shows Olivia a newspaper listing of the perfect house for them. He tells her he supposed the Observer was right, in every version of the future she had to die, but he never wants to lose her again. She has something important to tell him, too, something else the doctor told her. She’s pregnant. Peter looks stunned, then overjoyed. He kisses her, as a pleased Walter and Astrid look on from the doorway.
Back in the lab, Walter is preparing himself a late night snack, when September returns. September tells him they must warn the others. They are coming.
This was the season four finale of Fringe. It will return to Fox next season for it’s fifth and final season.