As we begin this issue, the mysterious figure who had been tailing Peter Parker in the finale of the last installment is still sticking to Peter like glue. After following him home from school, the stranger takes off and Peter uses the opportunity to garb himself in his Spider-Man get-up.
As Spidey, he follows the man to a telephone booth but can't overhear the stranger's conversation. The next day, the man is still following Peter as he heads over to the "Daily Bugle". On an upper floor of the building, J. Jonah Jameson sees an article about one Dr. Farley Stillwell and suddenly gets hit by a whopper of inspiration...create an anti-Spider-Man to use against his wall-crawling obsession.
We then find out that the stranger who has been following Parker is a man named Mac Gargan; and that he's in the employee of Jonah himself. It seems Jonah wanted to discover the secret behind Parker's ability to take such great news photos. Now, however, Jameson has a much more daunting task for the unsuspecting Gargan. Together, the pair head for the laboratory of Dr. Stillwell.
Against his better judgment, Farley is persuaded to transform Mac Gargan into a deadly new superhero: the Scorpion. Setting out to defeat Spider-Man, the Scorpion finds he has a seemingly limitless amount of strength and stamina. After tossing the luckless web-head through an empty water tower, Scorpion decides he is better suited to a life of crime than following the whims of a man like Jameson.
After robbing an armored car, Scorpion is confronted by Dr. Stillwell, who recognized that the creation process Scorpion underwent succeeded in allowing his evil nature to rise to the surface. Concocting an antidote, he tries to convince the Scorpion to drink it and save his sanity. However, the Scorpion has already embraced his evil tendencies and inadvertently causes the death of Dr. Stillwell.
Hearing of Farley's death, Jonah is burdened by the guilty realization that his personal hatred for Spider-Man has caused him to unleash something even more vile upon the city. Jameson faces more pressure when the Scorpion arrives at the "Bugle" to kill Jonah...seeing as how Jonah is the last living person to know the Scorpion's real identity.
Showing up on the scene in the nick of time, Spider-Man and the Scorpion do battle again. This time, Spidey gains the upper hand after ripping the Scorpion's prosthetic tail off. Receiving numerous cuts and bruises, the web-slinger also realizes his costume has sustained a large dose of damage. The issue ends with poor Peter pricking his fingers mercilessly while trying to stitch the shredded costume.