In the parallel universe, the Fringe Division investigates a case where a man was eaten from inside out by an extinct beetle. Meanwhile Broyles is considered missing and Lincoln is the head of the division. Olivia welcomes her boyfriend Frank that has just returned from Texas and wants to propose her. When a second man is also eaten by the insects, the Fringe Division identifies the scientist Dr. Armand Silva that was researching the cure for avian flu using this insect. Lincoln and Olivia goes to his address and split. Lincoln is locked in a refrigerating chamber while Olivia is brought to his laboratory, where she drinks water. Dr. Silva explains that only human beings are capable to host the beetle and a new cycle has just began. Olivia concludes that she has been infected by the insect and despairs.
As the story shifts back to life "over there," the absence of Colonel Broyles shifts the dynamic of the Fringe Team as they investigate a bioterrorist armed with an insect that has a taste for human flesh. Meanwhile, alternate Olivia is reunited with her beau, and Walternate remains determined to save his world but discovers there are certain lines he will not cross.
- Over there.
Fauxlivia waits for her boyfriend Frank to disembark from his Zepplin flight. They say a kissy hello.
At the airport bar, an older man chats up a fellow stranded traveler. When the younger one isn't looking, the older one swaps their glasses.
Back home,Fauxlivia's boyfriend says she didn't seem like herself when he they talked when he was out of town. She says the search for Broyles has been suspended -- they can't find him. Lincoln has been put in charge.
The man who was dosed froths at the mouth and barfs in a public restroom. He begs for help but the only person who comes is the man who poisoned him. He walks into the stall and when he comes out a swarm of cockroaches follow him.
Fauxliiva gets dressed in the morning. Her boyfriend suggests they get away for the weekend.
Fauxlivia reports to the bug scene. Bugs ate their way from the inside out. They haven't been able to ID the bugs -- which don't live long outside the body. As they watch the body a bug crawls its way out of the dead man's nose (yes, it's super gross).
At the Department of Defense, Walternate and Brandon examine the piece of the machine that Fauxlivia brought. Brandon tells Walternate there's been a breakthrough in synthesizing the chemical found in Olivia's brain. He plays the footage. A man is able to lift books with his mind. Then he collapses. The nine test subjects before him died within 30 minutes. Brandon says the man was the youngest subject. He wants to experiment on children. But Walternate won't have it.
Charlie and Fauxliiva visit Foster the bug girl. She's smitten with Charlie, whom she treated for his spider infestation. She recognizes the bug genus, but not the species. It's a beetle. She grabs a book it's a Skelter beetle -- they live exclusively in sheep. And all the sheep died out 10 years ago.
The older man who dosed the bugs does an experiment on the bettle, hoping to find an enzyme present. He doesn't and is hugely disappointed.
Back at Fringe, they check up on the other zeppelin passengers, all of whom are fine. Frank, who works with the CDC, is there to help. He says skelter beetles were symbiotic with sheep but these are attacking their hosts. Astrid suggests a Fringe alert to the public.
The scientist looks over his research on a tablet at a diner. A man sits down next to him and asks about it. The scientist mentions Jonas Salk and other scientists. The guy has heard of them. Then he mentions Dr. Armand Silver. The guy hasn't heard of him, but the man, who we assume is Dr. Armand Silva, says he will.
Frank goes in to Lincoln's office and asks if Fauxlivia can have a few days off after they wrap the case. He asks if he can keep a secret. Lincoln assures him he can.
Meanwhile, Charlie and Fauxlivia take calls from a panicked public. Then Lincoln goes over and immediately tells Fauxliivia that Frank is going to ask her to marry him. She's stunned.
Charlie interrupts with what he thinks is a legit call. A man at a biology complex used to work next door to a skeelter expert. Charlie and Fauxlivia meet with the guy, who says the guy was Armand Silva. He says the bugs were Silva's whole life.
Cut to the diner patron dead and spewing bugs and Silva collecting them.
The Fringe team is on the scene. They can't find a record of Silva after 2004. They notice the bugs are bigger than the first batch.
Walternate has a romantic evening in with a woman, not his wife. She asks what's wrong and he says there are lines he can't cross to save their world. Walternate is upset he lost Peter, he didn't factor in the girl. She's sure Walternate will find the answer.
Fauxlivia comes home to Frank making dinner. Frank says the CDC has and 1997 grant application on file from Silva, in which he claimed he was close to a vaccine for the avian flu. The vaccine was built on an enzyme that the skeelter beetle produced. Frank says to bring them back, Silva would have to modify the beetles to live in another host. The first batch wasn't mature enough, but the second ones were bigger.
She asks Frank what equipment Silva would need. She calls Lincoln to have them start looking for someone who bought all of it. As she's running out the door, grabbing her stuff, Frank sticks out a ring. He asks. She says yes.
Lincoln calls with an address for a storage locker. He meets Fauxlivia there. She tells him she said yes to Frank and is happy about it. Inside the storage space they hear something and go to investigate. Lincoln finds a refrigerated area and goes in. The door is shut behind him. He yells for Olivia but she can't hear him. She walks through the warehouse with her flashlight out. A monkey in a cage startles her, she whirls around and when she steps back the floor gives out under her. She goes crashing through to the floor below, landing on a table with bugs crawling all around.
When she wakes up, someone is feeding her water. It's Silva -- who used water to dose his last two victims. She's handcuffed to a chair. Lincoln tries to get out of the freezer. He finds a nitrogen tank.
Back with Silva, he sets up a camera on Fauxlivia, saying the whole world will thank him. He says humans are the only things that can host the beetles. He says his work is nearly complete. He talks about being robbed of his legacy when the sheep died out. Olivia works her hand slowly trying to get free of the handcuffs.
Lincoln freezes the door with nitrogen and busts out. He calls for back up.
Silva tells Fauxlivia the second batch weren't quite mature enough, but if he uses the queen it'll work. He says he just needs one more human host. He tells Fauxlivia the gestation has already begun. She throws up. Lincoln finds them, but she says they need Silva's help. She's been infected.
Charlie and the team arrives with Frank. Frank goes with Fauxlivia to the hospital.
Lincoln demands to be left alone with Silva. He puts a gun to Silva's head. He asks for something in his lab and says he'll help.
Frank wants to give Fauxlivia an anti-parasitic, but says it's a lot for her system to take. Her stomach hurts. They run a sonagram on her stomach. They see movement on the screen.
Back in the lab, Silva tells Lincoln that Fauxlivia will be fine. He takes the plastic bucket Lincoln hands him. He says she's not the final host.
In the ambulance, Frank prepares to inject Fauxlivia with the strong drug. The paramedic tells him to stop. Frank looks at the readings. "You're not infected, you're pregnant," he tells her.
In the lab, a beetle crawls out of Silva's neck. He says the queen is ready. As he dies, he tells Lincoln to make sure they spell his name right.
In the hospital, Fauxlivia isn't exactly thrilled at her news. Frank drops by. She tells him the baby is healthy. The fall and her adrenaline triggered some kind of morning sickness. Frank asks how far along she is. She doesn't want to tell him. Six weeks. He asks if she's in love with the father. She doesn't answer. He says that's all he needed to know. He leaves.
Brandon calls for Walternate. He says he might have another way to bring Peter back.
Fauxlivia comes home to find Frank's stuff in boxes. There's a knock at her door. It's Walternate. He knows she's pregnant. He says she's the mother of his future grandchild. He's thrilled.