Arrested for his crimes, Eddie Brock aka Venom was locked in a cell with savage killer Cletus Kasady. When he made his escape, the symbiote "gave birth" to a symbiote spawn which possessed Cletus. Altered by being born on Earth, the symbiote became twisted and together they became...CARNAGE! Proving too hard to handle for Spidey alone, he must now seek the help from the most unlikely of allies...Venom!
Grabbing the Fantastic Four's sonic gun (and the Human Torch to baby- sit it), Spidey is flown to the island via Fantasticar where Venom currently resides, content with the falsified knowledge that he killed Spider-Man. Needless to say, Venom doesn't take it too well when he discovers Spidey alive and well and standing on his beach. Venom attacks, destroying the sonic gun and casually wipes the floor with both Spidey and the Torch until Torch manages to rig a replacement sonic gun using the Fantasticar's sound system. With Venom weakened, Spidey is able to get Venom's attention by saying innocents are in jeopardy.
Meanwhile, in New York, the Carnage killing spree continues with no rhyme or reason. Just random chaos in an effort to inspire others to follow in his path to feel the ultimate freedom as he does. On the island, Venom informs the heroes about his spawn after conferring with his alien half and theorizes Earth's atmosphere is what makes Carnage so different from other symbiotes. Venom agrees to help only if he's allowed to go free. Reluctantly, Spidey agrees.
Back in New York, Carnage returns to one of his prior crime scenes to relax and watch some TV, only to get inspiration for his next kill. Little does he know the "good guys" are back in the city and about to go after him. Torch heads back to his team after being called and Venom leads the chase, being able to sense Carnage, with Spidey behind him. They find Carnage and attack, but Carnage proves too strong for both of them combined! Throwing a baby off the building to distract his opponents, Carnage gets away.
Carnage has now learned to block Venom's connection to him, so they can't track him anymore. But, upon investigating his hideout, Spidey stumbles across a clue to Carnage's next target: J. Jonah Jameson!