Superman hears that the committee is going to nominate Tom North as governor. He gets the information to press before it has been publicly released. The chief sends him and Lois Lane to cover the New York World's Fair. As the train is taking them to New York, Kent discovers that it's about to crash into another train. He leaps in between the two trains, and uses his strength to bring them to a stop.
When they get to the World's Fair, he hears about an exhibit on infantile paralysis that is not going to be able to be finished in time, he springs into action. He completes the necessary excavations, drives pilings into the swamp, and completes the exhibit.
He jumps to the top of the Trylon in order to locate Lois Lane. He catches up with her, and they run into Nick Stone, a noted criminal. He decides to pretend to be knocked unconscious to see what happens. Stone takes Lane back to his hideout and tells her his plan: to have his henchmen steal the Rhanee jewels that are being exhibited when the fireworks go off.
As he's about to shoot Lane, Superman shows up. He snatches the bullet out of the air just two inches from her head. Superman rushes back to the world's fair just as the fireworks are going off. He gets to the ground just as the two crooks drive off. He chases after them, pulls them out of the car, and drags them back to the police. And for good measure, he saves a parachuter whose chute has failed to open. Lois Lane jumps on him at just that moment. She plants a kiss on his cheek before he's able to jump off.
Mister Evarts of the Dodds-Bessing Steel Corporation telephones Wesley Dodds and arranges to meet him at the New York World's Fair. He instructs Dodds to bring the plans for the ray gun that he had invented. Dodds complies, but doesn't understand the request, as he is already donating the ray gun itself. At the fair, Wes and Evarts meets U.S. Secret Service agent George Henry. Henry insures that he will safeguard the plans and bring them to Washington. Suspicious by nature, Wesley surreptitiously pockets a crucial page from the blueprints.
Suddenly the lights flicker out, and when they come back on, the blueprints are missing. Evarts appears upset, but cites that there is little that anybody can do now. Wesley sneaks away and changes into his "Mystery Man" alter ego - the Sandman.
The Sandman discovers that the man he met with earlier was not the real George Henry. He goes to the steel foundry where he finds the real Secret Service agent bound and gagged. Releasing him, Wes learns that the impostor he met earlier was actually an international spy named Boris Leland.
The Sandman leaves the building and drives to Long Island. From there, he finds the spy ring gathering together on a private yacht on the Sound. He attacks the men and renders them all unconscious with his gas gun. He then discovers that Boris Leland had been working alongside Mister Evarts. The Sandman demands to know why Evarts would betray Wesley Dodds, to which Evarts explains that he was in financial straits and sold the plans to Leland to pay off his debts. The Sandman douses Evarts with his gas gun and takes him away.
This is the first comic book depiction of the Trylon and the Perisphere in Queens. These monuments will soon serve as the base of operations for the All-Star Squadron.