Milford, Mass. A speeding van comes to a halt on a suburban street, releasing a young woman, 20's, EMILY KRAMER, before speeding off again. The disoriented woman walks into a nearby diner and takes a seat at the counter. The young employee behind the counter, concerned for Emily's well-being, notifies MARTY, the local police officer. When Marty asks her what's wrong, she responds that "they" took her, and gave her a red medicine, and then a blue one. Convinced the woman needs psychiatric help, Marty attempts to restrain her, but this only agitates her more. And as Emily tries to break free, everyone in the diner screams and starts bleeding from their eyes. Soon Emily is bleeding too, crying out in pain until her head EXPLODES, splattering blood against the diner window.
The next day. The diner is a full-on crime scene, with investigators dressed in hazmat suits. Broyles informs our team that prior to last night's incident, Emily Kramer had been missing for two weeks. And while all of the victims in the diner were exposed to high levels of radiation, the radiation coming from Emily's body was three times that of the others. Walter has one question: where can he get one of those white suits?
Walter deduces that Emily was suffering from Bellini's lymphocemia, a rare autoimmune disease. But her disease appears to have been in remission, even though there is no known cure for Bellini's. Walter inserts a thermometer into Marty's skull, and based on the temperature he realizes that the radiation in the diner boiled everyone's brains. He demands to bring both Emily and the Marty back to the lab.
Patel Health Care. Olivia questions Emily's doctor, NADIM PATEL. He reveals nothing regarding Emily's condition except that her recovery was a miracle. Back at the lab, in addition to noting Emily must have worn hyacinth-scented perfume, Walter finds evidence that Emily was being held against her will -- and most likely the victim of some kind of experiment. Just then, Olivia receives a call notifying her that another person has been kidnapped.
CLAIRE WILLIAMS, the latest kidnap victim, also suffers from Bellini's. As Olivia and Charlie prepare to question Claire's husband KEN, Charlie wishes Olivia a happy birthday... today of all days. When Olivia tells Ken that Claire's case may be linked to Emily's, Ken says he's never heard of Emily Kramer, and he begs them to find his wife.
An experimental facility in an unknown location. Claire Williams is strapped to a table, as a woman in a hazmat suit takes her blood. She brings the sample to an observation room where she tells her boss, a man in a crisp suit, that Claire's a prime candidate.
Back in the lab, Walter prepares a demonstration of what happened to Emily and the other victims at the diner. Using a microwave gun, he explodes a papaya. But in the diner, Emily Kramer herself was the microwave. Walter has found broken capsules with traces of radioactive isotopes in Emily's blood, evidence of a form of time-release radiation therapy. The treatment cured her disease -- but also made her a perfect candidate for weaponization. Whatever was injected into her bloodstream caused the capsules to burst all at once, resulting in a burst of microwave radiation.
When Peter and Olivia arrive at Emily Kramer's house to ask about this mystery treatment, they discover a wake in progress., Olivia heads straight for Emily's room to rifle through Emily's things, searching for anything that might serve as a clue. She's caught in the act by Emily's mother. Although distraught, Emily's mother reveals that Emily Kramer and Claire Williams actually knew one another.
Olivia and Peter confront Ken Williams and demand to know why he lied to them. Ken confesses the story of how Emily and Claire became friends. Only 3000 people have Bellini's, too few to constitute a profitable line of research for the pharmaceutical industry. A small group of Bellini's victims pooled their resources to find their own cure, without industry help or FDA approval. Ken also reveals that Nadim Patel had been helping them.
In the experimental facility, the woman in the hazmat suit injects Claire with a red liquid, informing her that this is her cure, and then a blue liquid that will make her... special.
Olivia presents Nadim Patel with Ken Williams's story and demands to know who else is involved. Patel confesses that he passed information about the treatment to Intrepus, a pharmaceutical company, but that he never meant for anything bad to happen. Then Patel pulls a gun. As the two face each other, guns drawn, Patel gives her a name -- DAVID ESTERBROOK -- then turns the gun on himself.
Charlie reports that David Esterbrook heads up Intrepus's pharmaceutical research division and has worked on a wide range of controversial projects. Olivia decides to confront Esterbrook at a conference in Manhattan. She goes undercover, introducing herself to Esterbrook as Amanda Bennet. It turns out Esterbrook is the man in the suit from the research facility -- but Olivia doesn't know that. After gushing his praises and slyly probing him for information, Olivia reveals herself as an FBI agent. Esterbrook menacingly warns her to stay away.
Following the receipt of a phone call, Broyles reprimands Olivia for her reckless meeting with Esterbrook. From now on, Broyles expects to have EVERYTHING run past him.
In the experimental facility, Claire lies in bed as a rat is released into her room. The rat crawls all over her -- until it reacts like the people at the diner, bleeding and finally exploding. The assistant says Claire is ready, and that the capsules in her body can be triggered remotely. Esterbrook says they'll ship her out to their client in the morning.
Back at the lab, Peter announces that Walter may have isolated the isotopes in Emily's bloodstream. When Olivia snaps at him, Peter demands to know what's bothering her today. Olivia hesitantly tells him a traumatic story from her childhood. When she was a little girl, her stepfather would get drunk and abuse her mother. One day, when she was nine, after her mother had suffered a particularly harsh beating, Olivia mustered the courage to find his gun and shoot him. But she didn't finish him off. They took him to the hospital, and one night he slipped out, never to be seen again. And every year he sends Olivia a card on her birthday, just to let her know he's still out there. And then Peter realizes that it's her birthday today.
Peter suggests getting information on Esterbrook from Nina Sharp. Olivia refuses, noting that corporate espionage is illegal and Nina is unlikely to admit to it. So Peter goes off on his own, tracking Nina down at the Equestrian Center. He says they believe Intrepus is holding illegal drug trials and might be holding Claire Williams captive. Nina offers Peter a bargain: information now, for a favor-to-be-named later.
Meanwhile, Walter discovers that the victims were made radioactive through a dose of methyl eugenol, the chemical that gives hyacinths their scent. And he knows how to save them; he just needs to produce the counter-agent. Peter brings the good news to Olivia, along with an address where Claire is being held. He lies, telling her he got the tip from a friend in the reconnaissance office (not from Nina Sharp). Walter hands Olivia the antidote, informing her that it must be injected directly into Claire's jugular vein.
The FBI storms the facility. Olivia finds the observation room. Because the assistant has triggered the remote detonation, Olivia cannot enter the room -- so she slips the antidote through the door's safety slot. When Claire starts to seize from pain, Olivia screams at her to inject herself -- which she does just in time to keep her head from exploding.
Olivia confronts Esterbrook at Intrepus. She says they have a statement from his employee admitting that Esterbrook supplied her with the facility and the equipment to transform Emily and Claire into weapons. She slams him to the table and cuffs him, informing him that she's about to walk him outside where the press is waiting to take his picture.
Olivia checks in with Broyles, who is obviously upset at the public arrest of Esterbrook. She feigns innocence: "The press, they always get their pound of flesh." Then she admits to Broyles that she can be emotional, but it's what makes her great at her job. And he can fire her if he wants to, but she hopes he doesn't.
In Olivia's car, a radio announcer reports the news of how Esterbrook's detainment caused Intrepus's stock to drop considerably... while that of Massive Dynamic, its leading competitor, has shot up. Olivia realizes that there are consequences to her actions that she did not foresee. In Peter and Walter's hotel, Olivia tells Peter she knows where he really got his information.
On returning home, Olivia sees an envelope slipped under her door. No return address. She opens it up to find an unsigned card that says: "Thinking of you." And she knows exactly whom this card is from...