S7E5 · Rush

In Pittsfield, Virginia, Tony Reed and two other teenagers meet in the woods late at night, but they are interrupted by a sheriff's deputy. Moments later the deputy is murdered, killed with his own flashlight. Fox Mulder (David Duchovny) and Dana Scully (Gillian Anderson) later examine the deputy's body: the blow that killed the man was so ferocious that his glasses were pushed through the back of his skull. They question Tony, whose fingerprints were found on the flashlight, but he denies any part in the murder. Mulder and Scully agree that Tony is innocent, although Mulder's theory of supernatural involvement is not shared by Scully. Scully, on the other hand, suggests they question Tony's friends.

Mulder and Scully visit Tony's high school and speak with the two teenagers who were with Tony in the woods: the sheriff's son, Max Harden, and his girlfriend Chastity. Chastity seems concerned about Tony when the agents tell her he may go to jail. However, Tony is later released when the murder weapon mysteriously goes missing from the evidence room. Mulder and Scully review video footage from the evidence room that shows the flashlight simply disappearing. However, a blur on the video footage attracts Mulder's attention and later analysis by an expert reveals the blurred object is solid and matches the high school's colors.

When one of the teachers at the high school is attacked and murdered by an unseen force using a table and chair in front of many witnesses, Mulder suspects Max possesses some kind of paranormal ability and is using it to kill. Mulder believes Max's teenage hormones are giving him paranormal abilities that allow him to attack people without touching them. Meanwhile, Tony follows Chastity into a cave in the woods and stumbles upon a bizarre shaft of light. Once Tony steps into the light, he gains the same abilities that Max and Chastity have: the ability to vibrate at high frequencies, allowing Tony to move faster than normal vision can detect.

However, Max collapses and is sent to the hospital, where it is found he is suffering from exhaustion, withdrawal, a concussion, muscular tears and skeletal fractures–signs that his abilities are killing him. Mulder eventually deduces that he possesses superhuman speed. After Chastity sneaks Max out of the hospital, he returns to the cave. Later, the sheriff finds the flashlight in Max's room and confronts his son about the murders. Max confesses and attempts to kill his father, but Tony intervenes, taking the sheriff's gun and leaving behind the flashlight for Mulder and Scully to find; the sheriff is promptly taken to the hospital.

That night, Tony and Chastity head to the cave so that Max won't use up any more of the remaining power. Once there, Chastity has been knocked unconscious by Max, who uses his abilities to take back the gun from Tony before throwing it away. However, Chastity regains consciousness and takes the gun. She shoots Max from behind, then allows herself to be shot by the same bullet just as Mulder and Scully arrive. Afterwards, Tony is seen in the hospital recuperating. Numerous geological experts have examined the cave but were unable to identify anything unusual. The cave is then filled in with concrete, leaving the question as to what caused the events a mystery.