S1E4 · Conduit

At a campground at Lake Okobogee National Park in Sioux City, Iowa, Darlene Morris witnesses a flash of light outside her RV. She ventures outside to find her young son, Kevin, who claims that his teenaged sister, Ruby, has vanished.

In Washington, FBI Division Chief Scott Blevins informs Dana Scully that, unbeknownst to her, Fox Mulder has requested travel expenses to Sioux City based on a tabloid article about Ruby's disappearance. Blevins also shows Scully an X-File on the disappearance of Mulder's sister Samantha. When Scully asks Mulder about the travel expenses, he explains that Lake Okobogee was the scene of a series of UFO sightings in 1967; Darlene, then a member of a Girl Scout troop, was one of the witnesses.

When Mulder and Scully travel to Iowa and meet the Morrises, Mulder observes Kevin writing down binary code on a piece of paper; Kevin claims they are coming from static on a television screen. After submitting Kevin's code for analysis, the agents meet with the local sheriff, who tells them that Ruby was a juvenile delinquent who likely ran away. They also meet a young woman, Tessa, who says that Ruby had gotten pregnant and was planning to run away with her boyfriend, Greg Randall. The agents are unable to find Greg at the bar where he works; however, his boss tells them about UFO activity at Lake Okobogee.

Kevin's code is revealed to be part of a Defense Department satellite transmission. NSA agents ransack the Morris household, looking for any other material that might supposedly compromise national security. After the Morrises are taken into NSA custody, Mulder examines the charred roof of their RV, prompting him to head to Lake Okobogee. There, the agents discover sand turned to glass and a burned tree line, indicating the presence of a massive heat source. Upon encountering some white wolves, Mulder and Scully find Greg's body in a shallow grave.

On his person, Mulder and Scully find a note in Greg's wallet that eventually leads them to conclude that it was Tessa, not Ruby, who was pregnant. Under interrogation, Tessa confesses to killing Greg but denies Ruby was at Lake Okobogee that night. The agents return to the Morris' house, and, finding it deserted, discover the binary-covered pieces of paper laid out across the living room floor, forming an image of Ruby's face. Returning to Lake Okobogee, they find Darlene and Kevin in the nearby woods. A motorcycle gang appears, and as Mulder hurries to rescue Kevin from their wake, Scully discovers Ruby nearby.

Ruby is then seen in a hospital bed, with Kevin by her side. When questioned about her ordeal, she says she was told by an unnamed group not to say anything. Darlene also refuses to cooperate any further, given the ridicule that she faced after her past experiences. Back in Washington, Scully listens to a tape of hypnotic sessions in which Mulder recalls the night his sister vanished. Mulder, meanwhile, sits in a church, crying as he looks at a picture of his sister.