Description
U. S. Navy Commander Charles "Chuck" Prescott (Marshall Thompson) is unsure if his brother, Lt. Dan Prescott (Edwards), is the right choice for piloting the high altitude, rocket-powered Y-13. Air Force Space Command's Captain Ben Richards (Robert Ayres) insists that Dan is their best pilot, even though when piloting the Y-12 in the ionosphere, he began experiencing difficulties. Dan ignored flight regulations upon landing by seeing his girlfriend (Marla Landi) rather than filing his flight report. Captain Richards, however, insists that Dan pilot the Y-13 after being checked out and briefed by Dr. Paul von Essen (Carl Jaffe).
At 600,000 feet, Dan is supposed to level off the Y-13 and begin his descent, but he continues to climb, firing his emergency boost for more speed. He climbs to 1,320,000 feet (250 miles) and loses control while passing through a dense cloud of unknown material, forcing him to eject.
The New Mexico State Police report that a Mexican farmer spotted a parachute land south of Alvarado, New Mexico. Chief Wilson (Bill Nagy) meets Commander Prescott near the wreckage; the automatic pilot escape mechanism and braking chute operated perfectly. An unknown rock-like material has encased the Y-13's fuselage; testing shows that it is completely impervious to X-rays, infrared, and ultraviolet light.
Later that night, a wheezing "creature" breaks into Alameda's New Mexico State Blood Bank, brutally murdering one of the blood bank's nurses; the thing then proceeds to drink vast quantities of blood. The next day, a newspaper headline reads "Terror Roams State" and tells of brutal and inhuman slaughtering of cattle on a farm next to the crash site. Both the dead cattle and the blood bank nurse show similar wounds. When Chuck and Chief Wilson examine the nurse's body, Chuck notices shiny specks around the wounds, as well as on the blood bank door. They see the same specks on the necks of the dead cattle; they also find a high-altitude oxygen lead from the Y-13.
Chuck suspects that the killings may have something to do with the crashed Y-13 and requests that Wilson send sample specks to Dr. von Essen at Aviation Medicine. The next day, test results show that they are particles of meteor dust and show no signs of structural damage from passage through the atmosphere. Later, Dr. von Essen explains the results to Chuck: Wherever the encrustation occurs on the Y-13 fuselage, the metal is intact. In places not encrusted, the metal has been transformed into a brittle, carbon-like substance, easily reduced to powder. Chuck theorizes that the covering may be some sort of "cosmic protection".
Three more killings are reported. Chuck assumes that the same covering that protected the Y-13 fuselage also coated "everything" inside the cockpit, which means that the creature behind the killings must be his brother Dan. Chuck theorizes that when the canopy burst, Dan's blood absorbed a high content of nitrogen as the protective coating quickly formed over his body, allowing him to survive. But with Dan's metabolism having been altered in space, his body and brain have now become starved of oxygen on Earth; he must now replace that oxygen by consuming any type of oxygen-enriched blood.
When Dan's coated helmet is found in a car with his latest victim, Chuck's theory is proven correct. Captain Richards and Chief Wilson put in a call to Washington. Suddenly, the hulking, wheezing, encrusted creature that was once Dan crashes through a nearby window in their building.
Chuck realizes that his brother is finding it difficult to breathe. Dan then has Dr. von Essen open the high-altitude testing chamber while he taps into the building's public address system, warning everyone to stay out of the corridors. Chuck instructs Dr. von Essen to relay directions over the system to Dan on how to find the high-altitude chamber. Dan follows the directions while Chuck follows behind.
Dan stumbles into the chamber. Chuck realizes that his brother's hands are too badly deformed for him to operate the controls, so Chuck enters the chamber to assist him. A technician quickly increases the chambers' altitude to 38,000 feet, enabling Dan to breathe more comfortably. While Chuck uses an oxygen mask, Dan's humanity is slowly restored. He has no recollection of events after he ejected from the Y-13, but, through labored breathing, says "I just had to be the first man into space". After which he collapses, breathing his last.