Doctor Curt Connors has a bad track record when it comes to genetic experiments. His attempt to regrow his arm using reptilian DNA resulted in his transformation into a giant Lizard. His collaboration on the Venom Project with Eddie Brock ended in tragedy when Eddie seemingly died using the project to exact his revenge on Peter Parker, Spider-Man
And now, his latest experiment, which seemingly grew out of a sample of Peter's blood, has a nightmarish life of its own. This experiment has gone on to kill several times, and its latest victim was Gwen Stacy, friend and houseguest of the Parkers.
Aunt May returns home late to find the shrivelled-up body of Gwen Stacy behind her house.
At the Daily Bugle, Peter is ecstatic that his newspaper employer, J. Jonah Jameson, made good on his promise to portray Spider-Man in a more positive light. Before Peter can celebrate "Spider-Man" Christmas, he gets a phone call from Aunt May that sends him web-slinging across town, out of costume, to find his home once again surrounded by police, reporters and onlookers.
The police are grilling Aunt May when she notices Peter. The detective questioning her turns his inquiries to Peter, thinly veiling his suspicion that Peter had something to do with this. Captain Jeanne De Wolfe is on site, within earshot of Peter. Our hero hears that there have been a few similar deaths reported: possibly a mutant, a virus, or a vampire. Meanwhile, May fights the cops tooth and nail against their interrogations and their refusal to let Peter in his house.
Downstairs and alone, Peter rips open his book bag with the Spider-Man costume in it, fuming.
At Mary Jane's house next door, May lashes out at the non-cooperative person at the number she has for Gwen's mother. MJ's mom offers their home (recently free of MJ's dirt-bag father) for as long as they need it. In the den, MJ goes to talk to Peter alone. MJ mentions the moment her and Gwen shared at the mall. Peter wonders if he was a good friend to Gwen, if his costumed adventures are really doing any good, then chokes up and loses it.
In the middle of the night, Peter runs what he heard from the cops through his head, looking through the gamut of his rogues' gallery, until he remembers they mentioned a death at Empire State. Sure enough, when he looks out his window, he finds Doctor Connors. Peter goes out and attacks Connors, who he finds responsible.
Connors manages to talk Peter down and explain what happened. Apparently "Carnage" was a rejuvenating organism using Peter's DNA, Connors DNA, and work stolen from Peter's late father, who was an expert in cellular reconstruction. Peter expresses his utter disgust for Connors, only to find Carnage waiting for them both!