In Sensational Spider-Man #23, Dr. Curt Connors, a.k.a. the Lizard, is asked to have a look at a meteor rock by a doctor-friend of his (Dr. Treyman). Later that same day, Peter Parker is given a photo assignment, which takes him to the Bronx Zoo, where animals upon animals have seemingly committed suicide.

Mary Jane, thinking that Peter might be at the Daily Bugle, stops by and runs into John Jameson, who gives her a weird vibe. She pretends to have to go and takes off. As she leaves, she unknowingly drops her scarf, which is picked up by John.

Peter dons his Spider-Man costume and goes out on patrol to try and figure out why his spider-sense is suddenly going crazy (a puppy sets it off). While web-slinging across the City, he gets a disturbing phone call from Dr. Connors, who appears to be on the verge of transforming into the Lizard once again. Swinging towards Connor's apartment, Spidey tries to calm him down but at issue's end, both Dr. Connors and his son, Billy, who is with him, are transformed into lizards.

ACT 1: Detective Jonas Fogg is investigating the mutilation and murder of Dr. Treyman at the natural history museum. Treyman appears to have been partially eaten by something and whatever that something is, it is reptilian (based on saliva tests). Det. Fogg explains that the last person Treyman talked to, according to the museum's log, was Dr. Curt Connors, whom he asked to come check out an asteroid. A nearby cop, eavesdropping on the conversation tells Det. Fogg that they are dusting the meteor for fingerprints. Another cop inquires about Connors and Det. Fogg explains that he was a coworker of Treyman and that he can transform into the Lizard. The cop picks up his walkie-talkie and calls the dispatch to notify them that the Lizard is back and eating people.

ACT 2: When Spider-Man reaches the Connor's apartment and crashes through the skylight, not only is he confronted by the Lizard, he is also confronted by a smaller lizard – Billy Connors – Dr. Connor's son. Spidey is so caught off guard and distracted by the Billy-lizard that he does not sense the Lizard come up behind him, though he does feel it when the latter takes a bite at his shoulder. Spidey manages to break free and tosses the Lizard above his head and towards his son, who stands at the other end of the room. Both lizards are sent crashing through the wall and into the hall. A nearby neighbor – having heard the ruckus – comes out of his apartment to check things out. Wanting to protect the nosy neighbor, Spidey waves his blood arm at the lizards to distract them and get them away from him. He then takes off through a nearby window and makes his way to the rooftop, the lizards closing in behind him. When he reaches the rooftop, he comes face-to-face with the Black Cat, who just happened to be in the area. He barely has a chance to explain what is going on when the Lizard shows up on the rooftop and attacks them. Black Cat suddenly becomes enraged – as if possessed by a wild animal – and she takes him on.

ACT 3: Meanwhile at Avengers Tower, John Jameson shows up to give Mary Jane her scarf back (she lost it at the Daily Bugle in last issue). She doesn't really want to let him in but Aunt May overhears the "buzz" from John and invites him in for tea and biscuits. MJ is not pleased at all, especially because it appears that the whole city has picked that night to go bonkers and she hasn't heard anything back from Peter, which puts her on edge. After Jameson is buzzed in, he attacks the doorman in the lobby for drinking vodka on the job. What is up with him? Perhaps MJ does have a good reason to be scared.

ACT 4: Along the west side highway, in a dark alley, the creature known as Vermin is hungry for blood and looking for his next meal. He finds it quickly: a crooked cop-pimp in the process of beating one of his hookers. It is safe to say that the cop will never beat anybody ever again.

ACT 5:: While the Black Cat ferociously battles the Lizard, Billy-lizard lunges at Spider-Man and tackles him to the ground. The nosy neighbor, whom Spidey protected earlier, shows up on the rooftop, armed with a rifle, and aims it at Billy-lizard. Spidey is warned by his spider-sense but is unable to twist his attacker out of the line of fire. The nosy neighbor fires his rifle and the Billy-lizard goes limp and warm blood starts pooling around Spidey and him. The Lizard sees what is happening, stops trying to eat the Black Cat and lets out the most primal scream Spidey has ever heard. The Black Cat uses that opportunity to wale on the Lizard. Spidey webs the neighbor's rifle before he hurts anybody else and goes after the Black Cat, screaming at her to stop waling on the Lizard. In her blind rage, the Black Cat sends the Lizard off the roof. Spidey lunges past the Black Cat and over the edge of the rooftop and shoots a webline to try and snag the Lizard; he misses. The Lizard smashes into the pavement with extreme force but it does not kill him. He gets back on his two legs, howls out of anguish for his son, and disappears in the sewers. Back on the rooftop, Spidey verbally lashes out at the Black Cat and accuses her of trying to kill the Lizard after he asked her not to. The Black Cat replies that she somehow could not stop herself and explains that she felt extremely angry, though she does not know why. Spidey's thoughts reveal that he too somehow felt very angry. The nosy neighbor interrupts them and points out that the Billy-lizard has transformed back into his human self and that he is bleeding to death from his gunshot wound.

To be continued.