Canadian Air Force Colonel Clegg Forbes lands at a military hospital to check on his co-pilot and friend Major William Gart. The two recently flew an experimental spaceplane, the X-20, but it disappeared from radar for a day before crash landing in the desert with Gart sustaining a broken leg. Forbes questions Gart about the number of people on the mission and is confused when Gart says only the two of them were aboard. Forbes insists that their best friend and fellow pilot, Colonel Ed Harrington, was also present.
A flashback shows Harrington and Forbes leaving the hospital after passing their physical exams and visiting a bar. Suddenly, Harrington feels like he doesn’t belong in the world and vanishes after a strange phone call with his parents who deny his existence. Despite searching, Forbes can’t find any trace of Harrington.
Back in the present, Forbes finishes his story to Gart but is distressed by Gart’s claim of not knowing Harrington. When Forbes looks in a mirror and sees no reflection, he runs out of the room in fear. Gart tries to follow but Forbes disappears. The duty nurse confirms that no one named Forbes was ever in the hospital, causing Gart to also vanish in terror.
An officer arrives at the hospital and asks the duty nurse for a spare room. The nurse takes him to the now empty room where the three astronauts were and tells him it’s available. The hangar that housed the X-20 is now empty with only the sheet that covered the craft lying on the ground, leaving no trace of the plane.
