Poland, 1944: a grim Captain America is a passenger aboard the US bomber She-Devil on his way to rescue a Nazi scientist who wants to defect, bringing his great invention with him. Though he is skeptical of the reports, Cap is committed to the mission. Suddenly the bomber is attacked by flying saucers and shot down. Cap, who parachutes to safety, is the only survivor. He meets up with his contact, Lior Eschel, an attractive young agent of the Polish Resistance. Concealed amid the wreckage of planes destroyed by the Nazi saucers, Cap and Lior survey the enemy camp; Cap gets a look at the SS commander known as Der Metzger (The Butcher), a huge German with a mechanical eye and scarred face, which he reportedly received in a fight with a bear as a kid. With the sunrise Cap discovers that work at the camp is done by hundreds of Jewish prisoners, which leads him to expand the rescue mission to include the slave labor as well. At this point they are ambushed by enemy troops and a flying saucer. Lior is disintegrated by the saucer’s propulsion unit and Cap comes face-to-face with The Butcher. He hurls his shield but the giant Nazi catches it and knocks Cap out with a kick to the face….
Cap wakes up in a lab with the villain telling him that Lior had been forced to lead him into the trap by promises to release her captive family (who she did not know had already been killed by that time). The Nazis had intercepted Dr. Fleisher’s call for help and merely waited for the American Super-Soldier to be delivered into their hands. Cap is locked naked in a cell and scheduled for vivisection on the next day. There he meets Dr. Fleisher, who explains that he invented the flying saucers, which work by a central power source creating a zero-point field (hence the story’s title); he purposely withheld much of the information so that the Nazis have only three prototypes with limited range. The Butcher is losing patience and plans to kill Fleisher and reverse-engineer the remaining secrets. Cap rips his chains out of the wall and overpowers the guard. Donning his Captain America costume, he breaks into the room containing "the Bell," the huge reactor which powers the saucers. Cap leaves Fleisher to sabotage the device (which he does by placing an SS pin into the works, initiating a chain-reaction) while providing a major distraction by running through the base, taking out as many Nazis as he can, as quickly as possible. Outside, Cap is pursued by two of the flying saucers. He leaps through the air, lands atop one, pulls the pilot out, and steers this saucer into the other one, leaping to safety as they both explode. He finds The Butcher holding Fleisher captive and challenges him to battle. After a brutal slugging match, Cap tears out his opponent’s mechanical eye, partially blinding him; as Cap leads the scientist to safety, The Butcher opens fire, mortally wounding Fleisher, who dies telling Cap he knew Abraham Erskine, and wants his death to mean something too. Cap leads the Jewish prisoners to safety just as The Butcher sees smoke billowing from the vents, warning him that he has no time to escape the explosion which then destroys the camp. With the destruction of its power source, the last saucer crashes to the ground. Watching this, Cap assures the spirits of Fleisher, Lior and the crew of the She-Devil that their deaths did mean something: a chance for tomorrow.