Mild-mannered Jeb Dukes gets fired from his job in New Orleans, while his boss, Gary Garber, apologizes profusely. Jeb calmly strolls out of the office and out on to the street where, coincidentally, he witnesses a police chase that ends in a fatal auto accident. Jeb stays back, but is approached by a man awash in flames from the burning wreckage. The man seemingly walks into Jeb's body and then disappears. Suddenly, Jeb's eyes turn flaming red. That night, Jeb enters his office building and goes right up to his boss. He lifts a gun and fires at Garber.

Detective Franklin Potter is examining the crime scene when Agent Monica Reyes arrives. He shows her some artwork from Jeb Dukes' desk, but Reyes tells him that it is merely the insert from a popular rock CD. She dismisses the case as being satanic-based. Yet when she sees the victim's body, it appears to be charred from a fire. A second glance proves that it was only in her imagination. She is still unsettled by what she saw. Meanwhile, Mulder visits Scully and brings her a present. Before opening it, she doubles over in pain and Mulder rushes her to the hospital. Reyes calls Mulder on his cell phone, saying it is important she see him.

Jeb Dukes sits alone in a motel room, staring in fear at his gun. He raises it to his own head, but it gets hot and burns his hand. His face suddenly crackles. He rips at his skin, revealing flames underneath.

Mulder meets Reyes in an FBI file room. Showing him the file, Reyes asks if he is familiar with Doggett's son's case, which was the most emotional case she has ever worked on. When they found the boy, she had a vision of the body as ashes. Doggett also admitted to seeing the ashen body, but convinced himself that it meant nothing. Reyes once again saw the vision on a new case and senses that there is a reason for it happening a second time. At the hospital, Doggett checks in on a sleeping Scully. He envisions himself in a crime scene in a field, but a nurse enters the hospital room and shakes him out of it. Later, Mulder is in the FBI hallway when Doggett attacks him. "Stay out of my life!" he yells. Mulder tries to cool him down, saying that he was asked to investigate. Reyes approaches the men and explains about the recent case where she had a recurring vision similar to what they both saw in Luke Doggett's case. A suspect in Luke's case was killed in a car accident in New Orleans right outside of where the Jeb Dukes shooting took place. Doggett again warns her to leave it alone.

Reyes goes to the home of Jeb's sister, Katha Dukes, to plead for her help. Jeb calls Katha from South Carolina, claiming that someone else killed those people. A woman knocks on his phone booth door because she needs help with her flat tire. The next morning, Jeb wanders in a daze to a car pulled over with tire trouble. He is unaware of any events that may have taken place. He sees flames in the reflection of the car window, gets in and throws out the woman's purse. When he pulls off, the tire iron falls to the side of the road.

Scully awakes and sees Doggett in her hospital room. He asks her what changed her mind about not believing any of the paranormal on the X-files. She admits to being afraid to believe. Suddenly Doggett sees a vision of Reyes in a field at the familiar crime scene. She is surrounded by sheriffs and looking at a body on the ground. Meanwhile, Reyes comes to Mulder in the X-files office. He has found no connection to other cases with the same kind of visions. Reyes tells him he is wrong because she believes there are patterns.

Doggett arrives at a crime scene in Spartanburg, SC where Mulder is waiting for him. Reyes' case has another murder victim. Doggett's reoccurring hallucination turns into reality when he sees her standing over a body, surrounded by sheriffs. He looks at the woman lying on the ground and tells Reyes that he does not see the ashen remains. Reyes is insistent that there are connections and that it may be a thread of evil. Mulder asks her to leave Doggett alone if the man really doesn't see anything.

Later, Mulder stops by the hospital to see Scully. She had a partial abruption in the uterus wall but she will be fine. He places his hand on her belly and they smile. Scully tells him that she likes Agent Reyes. Mulder is surprised. "You're nothing at all alike." "Neither are you and I," Scully responds. He says that he can't help Doggett if he doesn't want to be helped. She is convinced that Doggett is worth the effort.

Jeb Dukes is at his sister's house. Although he claims he hasn't committed any murders, Katha sees blood on his face and doesn't believe him. Jeb asks her for help, but Katha's fears deepen over the safety of her daughter. Doggett, meanwhile, submits to investigating the Jeb Dukes case when Monica enters the office. She wants him to be honest with himself about what he saw at the Spartanburg crime scene, but he says that feelings don't solve crimes. "What are you scared of?" she asks. Reyes assures Doggett that he did everything he could to save his son. She receives a call from Katha who says that Jeb is at her house. Doggett wants to know what link Jeb may have to his son, and the agents race off to the Dukes home. When they arrive, Katha tells her brother that Reyes only wants to talk to him, but Jeb is scared and takes Katha's daughter as hostage. Doggett holds him at the stairs, but puts down his gun when Jeb threatens to kill the little girl. Reyes shoots Jeb from the other side and Doggett calls for help.

Jeb is transported to Washington Memorial Hospital and the agents follow. Reyes surmises that perhaps saving the little girl was the connection to Doggett's son. She tells Doggett that there is nothing more for him to do, and he goes down to Scully's room. Watching her sleep, he again sees the vision in the field where Reyes is surrounded by the sheriffs. The men back away to reveal that Luke Doggett is the unseen body lying at their feet. The body turns to ash. Mulder interrupts him and asks if he thought there really was a connection to his son's death. Mulder wonders whether evil is like a random disease: while most people have immunity, others may catch it at a weak moment. In the ICU, Katha witnesses her brother's body seizing. The doctors try to revive him but his heart stops, and Jeb Dukes is declared dead. Katha stands crying over him, accusing Reyes of killing him. An invisible spirit floats from Jeb to Katha, causing her body to convulse and her eyes turn to flame red. She strikes Reyes and grabs the agent's gun. Doggett arrives in time to capture Katha. "It's over," he tells Reyes. "It's never over," she says.

Mulder comes once again to Scully's house and reminds her to open his gift. It is an heirloom doll from his family. She thanks him for the other gift he gave her -- the courage to believe. "I hope it's a gift I can pass on," she says, tearfully.

Back at the hospital, Katha Dukes is alive and strapped to her bed. Doggett stares intensely at the woman, wanting to believe that this will prevent the evil from spreading again.