In 1977, pictures from Mars showed what looked like a sculpted face in the landscape, the jumping-off point for the episode. Lt. Col. Belt, now supervisor of the shuttle program, was on that mission and has flashbacks of a spacewalk, seeing that same face looking down at him.
Meanwhile, Mulder and Scully are approached by Michelle Generoo, NASA's Mission Control communications commander, who says a recent lift-off was aborted seconds before launch and that she fears a piece of equipment has been sabotaged. She wants the agents to help solve the case before her fiancé flies the next mission.
Mulder and Scully go to see Belt, who is Mulder's childhood hero, tells them there's nothing to worry about, and the shuttle launches without incident. Soon, however, communication with the spacecraft is lost, and on the way to Mission Control Generoo's car crashes as the strange face zooms in at her through the fog.
The three arrive at mission control and learn the shuttle is in direct sunlight and they can't rotate it. Generoo believes someone is blocking the uplink. They reestablish communications and get the shuttle rotated. Although the shuttle is damaged, Belt tells the astronauts to deliver their payload, fearing that millions of dollars would be lost, and the space programme crippled, if they don't follow through. Mulder is disillusioned, but Belt tells him things are different now and that you make the front page today only if you screw up.
Alone Belt has another flashback, screaming as the astral presence escapes his body, heading skyward. The shuttle feels a dull thump and experiences an oxygen leak, just like what happened on Belt's mission years earlier. The astronauts tell Houston that they see some kind of ghost outside the ship.
The agents examine the records, which show that Belt knew about the equipment flaw and possibly the O-ring failure on the Challenger. Belt collapses, saying the astral force lived in him, controlling him. At his urging, they alert the shuttle to change its trajectory and they are able to land it successfully. Belt himself, wrestling with the presence, leaps to his death.
Mulder, a fan of Belt's from long ago, lauds his sacrifice. "Something had possessed him. Something he has seen out there is space" – something, apparently, that didn't want company…