As Peter Parker's Aunt May lies dying in the hospital, victim of the effects of radioactivity in her blood stream . . .

. . . A sympathetic Dr. Connors waits for Spider-Man to bring the ISO-36 to him . . . For it is the only serum which might save Peter's Aunt!

But, the stolen serum is in the possession of Dr. Octopus, whose masked henchmen wait outside a steel door, as Spidey and Doc Ock battle within . . . !

And, none suspect that a sudden leak in the underwater dome of the hidden hideout is growing bigger--and bigger--!