Captain America is escorted into a prison accompanied by the jeers of the convicts—and summarily tossed into a cell, his shield confiscated. His tough guy cellmate Thumper Morgan, seeking revenge on Cap from the last time they tangled, picks a fight, figuring that the cramped cell will hinder the hero’s acrobatics. It doesn’t, and Cap knocks him cold. Cap thanks his other cellmate, Tony Zack, a slum youth doing time for robbery, for not getting involved. Thumper assures Cap that Tony is getting a solid education in the ways of criminals—which is the issue Cap is concerned with. When Tony asks why Cap is in jail, the hero responds, "To escape." That evening, Cap joins Warden Michaels at a press conference. The previous security system depended on a magnetically-powered door that opened only at the sound of the code word, "Captain America." It was only a matter of time before a prisoner unwittingly said the name of the Avenger nearby and the door swung open, only the presence of a contingent of guards stopped a mass jailbreak. The media made a big fuss over the incident so the warden was replaced and security system changed. To demonstrate that the prison is secure, Warden Michaels has asked Captain America to attempt an escape as a demonstration; this will be the preliminary step toward instituting a series of reforms to focus on rehabilitation rather than mere incarceration….
The next day in the prison yard, a gang of cons jump Cap during an exercise session; Cap easily defeats them. Trustee Deacon, who overheard the press conference, informs Thumper Morgan of Cap’s plan to escape, so the brutish con lays plans to follow him out when he makes his break. In the metal shop another bunch of punks assault Cap and Morgan joins in defending the Avenger, as he is depending on Cap to lead him to freedom. Cap advises leniency for his attackers.
That night, Cap slips from his cell and heads for freedom. Morgan, Deacon, and their cronies via closed circuit cameras, mobilize the guards quickly to recapture many of the convicts. Tony warns Cap about the mass escape and Cap makes sure the young man is safely locked up before continuing out of the building. The last remaining prisoners see Cap use the rope on the flagpole to swing over the wall and they lose heart since such a move would be impossible for any of them, and they are recaptured. Cap returns and encourages the warden to continue with his reform program, starting with Tony Zack, who is not a hardened criminal. When a cynical reporter claims the system failed, a woman journalist rises to the defense: the system worked, only one man managed to escape and he was no ordinary man, he was Captain America!