When a detective mysteriously uncovers the remains of an FBI agent who disappeared in the 1940s while investigating a murder case similar to a modern-day one she is investigating, Mulder and Scully believe that the original killer had passed his genetic trait of violence to his grandchild.
A pregnant police detective in Aubrey, Missouri, has frightening visions. She managed, using them, to locate and find a body. Mulder and Scully identify the remains as a missing FBI agent who disappeared with his partner 50 years ago. They are puzzled by the revelations of the detective.
A lady enters a room, and tells a guy named Ryan that she is pregnant. During the conversation, Ryan receives a call. After he puts down the phone, he tells the pregnant lady to meet him at a motel where they can talk. Cut to the motel, the pregnant lady starts to hallucinate while entering the motel room, and she sees a man taking a dead body out of a truck and carrying it to bury somewhere. Through this vision, she manages to locate the dead body and dig it out from where it was buried. With dead body, she also finds a badge that says FBI on it.
Cut to the FBI headquarters, where Scully and Mulder are discussing the teeth X-ray to determine the match. Scully asks Mulder who they belong to. Mulder replies, "Special Agent Sam Chenny" and also adds that he was an FBI agent 40 years ago and was a legend investigating serial murders. His partner and Sam Chenny disappeared while investigating serial murders in 1942 until his body was found the pregnant woman, which is known to be a local detective.
Cut to the crime scene, the pregnant woman (BJ) has conversation with Mulder and Scully about how she found the body. She lies to them that she was having problems with the car and she saw a dog digging far away at night.
Cut to the Coroner's office, Scully is conducting an autopsy on the corpse. They discuss the case in 1942 which was being investigated by Agent Sam Chenny when he disappeared. BJ enters the room while Scully and Mulder are talking and ask them if they have made any progress on the case. Looking at the agent same Chenny's Sculton , BJ sees another vision where Agent Sammy is being tortured by the killer.
Cut to the washroom, where Agent Scully has a brief conversion with Detective BJ in which BJ talks about the nightmares. She says that it's always that the same in the house and feels almost familiar; she recognizes the man but doesn't know him. They return to the office where Mulder is trying to find the letter on Sculton which he can't identify. BJ seems to identify the letter and says the letters are "brother". Detective Telmore enters the room and looks at the files, and says these are crime scene photos and they are sealed, and that no one has access to them. Mulder replied that he is mistaken and they are from 1942 serial murders. Telmore looks at the files again and sees the date; he is stunned because the same kind of incident took place 3 days ago where a young woman was murdered and the word sister was carved onto her chest and painted on the wall. Meanwhile, another detective enters the room and says that there has been another one.
Cut to the crime scene of another murder, where a woman named Johnson was murdered in the same way. BJ looks at the dead body and identifies her and says that "it's the woman in my dreams".
Cut to the Lincoln Park, Mulder, Scully and BJ talk about the BJ's dream. BJ describes the suspect she sees in her dream. BJ looks through the old album of criminals and she identifies the guy she sees in her dreams. Scully and Mulder try to link BJ's connection to all these; Scully determines that BJ's father was a cop and she might have had seen the suspect when she was a kid and is starting to remember it all now. Scully and Mulder head to Cokely's house to interrogate the prime suspect.
Cut to BJ's house, BJ has a dream and she shockingly wakes up. She has blood all over her body and heads to the mirror to check; she finds the word sister written on her chest. She has another vision and finds yet another body buried in her house. At the hospital, she identifies the guy who did to her and she says he was Cokely. Cokely was brought to the police station for questioning. Back at the motel, the blood test was identified as Cokely's blood.
Scully and Mulder goes to Mrs. Thibedeaux, a woman who was attacked by Cokely 40 years ago. While questioning, Mulder somehow finds out that Mrs. Thibedeaux was pregnant with Cokely's child. Then she admits it and tells them that she gave the child up for adoption. Adding more, she says that the child was a spawn of evil. She hands over the adoption agency's address.
Cut to the motel, Scully and Mulder are discussing the murder, and Mulder comes to the conclusion that Cokely is not responsible for the murder but Cokely's grandson or daughter are genetically connected and somehow Cokely's memory was inherited killings people's from Cokely. Meanwhile, they find out that Thibedeaux and Cokely's son is BJ's father. The conclusion is that BJ is responsible for the murders.
BJ goes to Thibedeaux's house to kill her but finds out that she is her granddaughter. Instead, she goes to Cokely's house to him and Mulder follows. She eventually kills Cokely and attacks Mulder. The episode ends with BJ in prison. A voice-over from Scully reports that BJ has been placed on suicide watch, after she tried, unsuccessfully, to self-abort her child.
In her cell, BJ rests her hands fearfully on her stomach, terrified at the thought of what her child's legacy will be.
Scully: Mulder, I don't think BJ was in the woods that night because of engine failure.
Mulder: What are you talking about?
Scully: Well, the Motel Black would have been a perfect meeting place. Away from town, away from his wife.
Mulder: What do you mean?
Scully: It's obvious BJ and Tillman are having an affair.
Mulder: How do you know?
Scully: A woman senses these things.
- Terry O'Quinn as Lt. Brian Tillman
- Deborah Strang as Detective B.J. Morrow
- Morgan Woodward as Harry Cokely
- Joy Coghill as Linda Thibedeaux