A new nuclear reactor has been built in the heart of Manhattan, and Peter Parker's science class is researching it. Peter is asked by his attractive classmate, Sonya, to help her that night with research about the reactor. As Spidey is making his way to Sonya's home, trouble is brewing. A demented radiation specialist breaks into the new reactor and threatens the city with ransom; unless he is paid $10 million, given amnesty from prosecution, and given permission to build his own reactor, he will use anti-gravity rays on Manhattan to lift it into the sky. When his demands are refused, he does exactly that, and makes a ransom demand of $100-million, along with the other conditions, and unless his demands are met he will deactivate the ray & send Manhattan plummeting back to earth. Spidey must abort his date with Sonya & tunnel into the reactor to stop the madman. The specialist, who has speculated Spidey's powers came from radiation, tries to neutralize them by subjecting Spidey to anti-radiation. Unfortunately for him, Spidey resists the anti-radiation by force of will & kicks the specialist in the face. The stunned specialist fires his gun at Spidey, but misses, and the ray from the gun hits the controls sustaining the anti-gravity ray. As Manhattan starts to drop like a stone, Spidey must neutralize the psychotic specialist quickly.

When a city bank mysteriously vanishes into the street, J. Jonah Jameson sends a reporter named Hammond to investigate, while sending Peter to visit a scientist who has recorded voices supposedly from the center of the earth. Peter visits the scientist, and when a recording is played for him, he discovers it is the men - or beasts - who made the bank disappear, and they are plotting another one. Realizing it is only a few minutes until the plot is carried out, Peter becomes Spidey & heads for the bank. Sure enough, the bank disappears into the earth! Spidey follows it down & finds a strange kingdom of creatures - the Mole-Men. When the leader announces a plan to subjugate the people who were in the building when it was taken, Spidey moves into action & overpowers the Mole-Men, and both they & their hostages will be in for a surprise.