When a second victim is discovered with injuries to the back of the neck, Fringe division is called in to investigate. Walter does an autopsy and discovers that the injury was inflicted by a human bite; the wound is infected by a rare genetically modified syphilis virus and all the spinal fluid has been drained. Tracing users of the virus leads the team to a scientist with connections to ZFT. His story leads the team to find more victims and a desperate race against time to track down a killer with a dangerous addiction to human spinal fluid.
After the second murder of a man with severed spinal column, the Fringe Division is assigned to investigate the case. Dr. Bishop discovers that the spinal fluid has been completely drained out; there are marks of human teeth on the spot and the killer's saliva is infected by an extinct syphilis virus. After an investigation with the CDC, they learn that the sample of the extinct virus was delivered to the Lubov Pharmaceutical for research purpose. Soon they learn that the laboratory has connections with the bio-terrorist group ZFT. There is an FBI raid in the Lubov Pharmaceutical and they arrest the crippled scientist Nicholas Boone. He offers to respond to the FBI interrogatory provided the FBI rescues his beloved wife Valerie Boone that was kidnapped by the ZFT. He also gives an address where she would supposed be and Olivia and a team invade a restaurant but do not find Valerie. Nicholas admits that his wife that was infected by the ZFT is the killer and he needs samples of the virus to find an antidote. Further, he became crippled using his own spinal fluid to feed Valerie. Now he teams up with Dr. Bishop expecting to find a cure for the virus. Will they be capable to save Valerie?
Walter examines a number of dead bodies that had the spinal fluid removed. Olivia and Charlie go after the scientist who created the person behind the murders.
- A man gets dressed as a news report about a gruesome murder plays on TV. The body was mutilated by what might have been a hunting knife, the reporter says. The man folds a hunting knife and puts it in his pocket.
After parking, the man, Bob (Richard Short), answers a call from a woman, asking where he was last night. She called and couldn't reach him. She's out of town. He lies to her about having a business meeting as he goes into a club, scoping chicks. He finds a blonde he likes, but her date interrupts. He finds another girl, who has that sort of dead-around the eyes look, except her eyes are straight up Debbie Gibson electric blue. He tells her, too, he can tell she's his kind of girl.
Back at his place, they make out. And then she snaps his neck. Just like that.
Bob's girlfriend calls and can't reach him. The girl fixes her make-up in the mirror. Bob lies, not just dead, but totally decapitated and neck shredded, on the bed.
Olivia (Anna Torv) and her sister host a couple who tell them how they met online, through a service called TwoSinglesTogether.
Rachel (Ari Graynor) answers the doorbell. It's divorce papers from her husband.
Olivia gets a call from work.
They check out shredded Bob. He died the same way as the victim two nights ago. Walter (John Noble) says decapitation and shredded neck reminds him of shrimp cocktail. He elaborates, but on the off chance you might eat shrimp cocktail again, we'll leave that out.
Peter (Joshua Jackson) checks to make sure Olivia's OK as Walter finds bite marks on Bob's neck. His spine's been chewed out. Walter is sure it was done by something exciting.
Olivia briefs Broyles (Lance Reddick). Bob's car is missing. Also, Olivia asks Broyles if he is satisfied with his divorce attorney. She gets the number. He guesses it's for Rachel.
At the lab, Walter does two autopsies, really enjoying himself. Astrid (Jasika Nicole) brings the lab work. Their spinal columns were drained of fluid. They also have traces of syphilis bacteria. "Great, so the killer has syphilis," Peter says, "should have worn gloves." More interestingly, the syphilis strain is ancient.
Olivia visits the CDC. A nervous man tells her a lab ordered it four weeks ago. The lab also ordered others throughout the years. The lab ordered a compound used in bioweapons, the same compound used to kill Agent Kent (whose eyes and mouth grew shut with skin). It could be ZFT.
Olivia and an assault squad storm the lab, which is in a house in a residential neighborhood. Inside, Olivia finds a dog in a cage with the same electric blue eyes the woman who shredded Bob had. They find a man sawing on an animal.
They bring in Dr. Nicholas Boone (Jefferson Mays), a mild mannered scientist in a wheelchair. Olivia and Charlie (Kirk Acevedo) show him the pictures and ask what happened. Charlie asks how long he's been a follower of ZFT. Boone reacts like he's heard of it.
He says someone was dosed, but they have to help him. They have his wife.
He says he's being punished by ZFT because he tried to get out when he realized what his work was used for.
Olivia tells Broyles that Boone's wife hasn't been to work in three weeks. She's tired of seeing people die (81 Fringe cases so far, not counting the airplane).
Boone gives them an address where he says his wife is being held. A restaurant in Chinatown burning five times the power it should be.
The Bishops visit Boone's house lab. They check out the split open animal and blood everywhere. Walter pokes around.
Charlie and Olivia prepare to lead an assault on the restaurant. Rachel calls Olivia in tears. Her soon to be ex is suing for sole custody of her daughter Ella (Lily Pilblad). Despite the fact she's surrounded by SWAT in a moving van, Olivia takes the time to talk her down, before excusing herself for a "meeting."
In the restaurant they find food and cooks, as might be expected. Olivia, who it turns out speaks Chinese, asks an employee where Boone's wife is.
At HQ, Broyles tells Boone his wife isn't there. He knows. He wants to talk to Olivia. He directs her to a refrigeration unit. Inside is filled with vials of the contagion. He needs it to make an antidote. ZFT didn't kidnap his wife, they dosed her. She's the one doing the killing.
Valerie Boone lurks hungrily outside a club. She spies a young stud, whose spinal fluid must look tasty. He drives her home. As he kisses her in the car, he notices that she's burning up. She apologizes, then develops razor teeth and gnaws into his neck.
Roxbury, Mass. Police and FBI check out the latest spinal scene.
Broyles shows Olivia a video camera found in Boone's house, telling her to note the date. She brings it in for Boone. It shows him filming his wife. He's standing then running and leaping. Not in a wheelchair.
The video was taken three weeks ago. Olivia asks him to explain. He says his wife needs to feed, she can't help it. He began to feed her his spinal fluid until he couldn't give any more. The contagion burns through her spinal fluid.
He says ZFT wanted him to create a human nightmare. He also created the skin growth toxin. They wanted to show off. He made six vials. He wants to work on the antidote and then he'll tell them everything.
They take Boone to Walter's lab, where the two scientists dork out.
Charlie calls Olivia. They found Dead Bob's car. It's totally stripped.
Walter and Boone think they can kill the super syphilis with super penicillin.
When Olivia tells Peter about the stripped car, Peter says he knows a guy.
Olivia talks to Mako (Dante Nero) the fence, who tells her GPS was wiped for resale. He then says where they found the car. Walter tells Boone he's honored to have his intellect in his lab. Boone knows it's high praise. They talk science until it comes around to Walter's former partner, William Bell, head of Massive Dynamic.
Weymouth, Mass (where Mako boosted the car) Olivia and Peter try to figure out what Boone's wife was doing there. Peter looks in the bushes and finds another body.
Walter and Boone prep to try the antidote on the rat. They shoot it up as Peter wheels in two more bodies. Olivia asks Boone where his wife is getting her victims.
Astrid says one reeks of alcohol. She uses a black light to check the men for club stamps. She recognizes one. When the lights come back on they see the test rat is dead. Boone begs Olivia to capture his wife alive.
Olivia and Peter go clubbing. Valerie is there. Peter uses a heat sensor to scan for her super hot body heat.
At the lab Walter thinks they're missing something. Boone says the contagion requires cerebral spinal fluid and the antidote must as well. He says the only spinal fluid they know compatible is his. He says he's got enough left. Walter goes for it.
In the club, Peter finally finds Valerie, but they lose her.
Walter draws spinal fluid from Boone, who notices a nearby video camera and finds it interesting.
Valerie leaves the club and Charlie hits her with a tranquilizer.
Walter works on another antidote but Boone isn't doing well. Walter knows Boone lied to him about having enough spinal fluid. Boone asks him how far he'd go for someone he loves.
Peter and Olivia drive tranqued-out Valerie to lab. They think she'll be out for hours. Naturally, she isn't. She opens her eyes.
Peter and Olivia talk about the kind of love making Boone go to great lengths as Valerie pops up, bares teeth and goes after Olivia. Peter, still driving, gets Olivia's tranq gun and shoots her up again.
In the lab, Boone has had a stroke but watches as they inject his wife. She shrieks a high pitched whine, thrashes then goes limp. Walter checks her eyes. They go from freaky blue to a more normal color. Olivia checks on Boone. He has died.
As paramedics wheel Valerie away, Walter gives Olivia the video Boone asked him to give her.
She and Peter watch it. Boone held up his end of the deal. He tells her about ZFT, which includes some names he thinks she's already heard (we don't get to hear more).
Olivia goes into a bar and finds Broyles. She tells him Boone says the man funding ZFT is William Bell.