A high-speed chase in Nevada ends when a woman riding in the car dies of a popped head. Mulder and Scully have been demoted to routine check-ups on large purchases of fertilizer, but Mulder persuades Scully into a side trip after seeing a news report about the incident. Patrick Crump, the car's driver, begins to panic after suffering a nosebleed and ringing ears in his cell. Mulder notes how Crump and his wife were heading east after stealing a car, then made a U-turn and went west until they were stopped.
Crump escapes an ambulance while he is being transported to a hospital and takes Mulder hostage, forcing him to drive. Scully thinks some sort of disease is at large after another body is found with the same symptoms near Crump's hometown. Mulder realizes that Crump needs to keep moving west or he'll suffer the same fate as his wife. An analysis of the bodies finds there isn't any sort of infection.
Scully and a CDC team check out the Crump residence, where a panicked dog also dies after he stops moving. Crump says the police chase was a result of similar conclusions when he tried to bring his sick wife to the hospital, and thinks it's part of a government plot. Scully finds that the Crump's neighbor, who is deaf, is unaffected even if her birds aren't. Running low on gas, Mulder ends up stealing another car at a gas station to keep Crump moving.
Scully finds several dead birds outside the Crump residence, and a metal plate that denotes federal property. She finds that the Navy has electrical equipment stationed in the Crump's hometown, and that it experienced a brief power surge; they say its effect on organisms is classified. Scully tells Mulder that she thinks the hum from the Navy system may have found resonancy with the human skull, and movement is the only way to prevent a pressure blowout inside the ear.
The unpleasant remedy Scully proposes involves jamming a large needle into Crump's ear to relieve the pressure. She manages to arrive on the California coast ahead of Mulder and Crump, but Crump has died by the time they get there. Kersh is more concerned with the travel expenses and the agents pursuing what looks like an X-File, but Scully says the Navy has shut down the electrical array and so their work with the case has saved lives. Of course, the Navy says the shutdown was just coincidental.
Bryan Cranston, who plays Patrick Crump, is best known for his roles as Hal on Malcolm in the Middle and Walter White on Breaking Bad. Mindy Seeger, who plays a coroner, played a character named Chris on several episodes of The West Wing while Michael O'Neill (a patrol captain) played Secret Service Agent Ron Butterfield on the same show. Frank Buckley, who plays reporter Benjamin Buckley, is an actual news reporter for KTLA in Los Angeles.
Episode Body Count
Vicky Crump: dies of a pressure overload after she stops moving west.
Meter reader: Scully fears a communicable disease after another body is found with the same symptoms.
Crump dog: also dies in the same manner.
Two parakeets: found in the Crump's neighbor's trailer.
At least eight dead birds: found outside the Crump trailer.
Patrick Crump: dies of a pressure overload before Scully can try a remedy.
Cumulative Body Count (119/202 episodes, 1/2 movies)
Humans: 1,439Creatures: 99
Grand Total: 1,599