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.

In Sensational Spider-Man #24, when Spider-Man reaches Dr. Connors' apartment, he is confronted by not one but two lizards. One is Dr. Connors, the other is his son Billy. A battle naturally ensues during which Spidey is hurt. As he flees to the rooftops, the two Lizards in tow, he runs into the Black Cat, who comes to his aid. As if possessed by a wild animal, the Black Cat savagely attacks the Doctor-Lizard while the Billy-Lizard attacks Spidey. While the Black Cat manages to send the Doctor-Lizard flying off the building and into the ground several floors below, Spidey has his hands full with the Billy-Lizard. However, he gets unexpected (and unwanted) help from a nosy neighbor armed with a rifle when the latter shoots the Billy-Lizard. At issue’s end, the Billy-lizard has transformed back into his human self and he is bleeding to death from his gunshot wound.

While all this takes place, Mary Jane gets an unexpected visit from John Jameson, who is bringing back the scarf she lost when he last saw her at the Daily Bugle. MJ feels uneasy about letting him in Avengers Tower but Aunt May invites him in for tea and biscuits. On his way in, John attacks the doorman in the lobby for drinking on the job. He then makes his way up.

This issue also marks the long-awaited return of Vermin who unwillingly comes to the aid of a prostitute by killing her crooked cop-pimp and feeding on his flesh.

This is where this issue picks up.

ACT 1: Not wanting to bring Billy Connors to a hospital, for fear that they would want to experiment on him, Spider-Man, accompanied by the Black Cat, heads over to the Fantastic Four Headquarters to get help from Susan and Reed Richards. Wasting no time, Reed puts Billy inside some kind of bio-bath, which kind of looks like the Bacta tank that Luke Skywalker was put in in the Star Wars movie. While Billy slowly recovers from his injuries, Spidey, Reed, Susan and the Black Cat discuss the recent outbreaks of violence disrupting the City. Reed comes to the conclusion that he needs to run some additional tests on both the Black Cat and Spider-Man, as they both seem to have experiences bouts of extreme anger (more so the Black Cat).

ACT 2: As the elevator door to the Parker loft in Avengers Tower opens, John Jameson, as the Man-Wolf, lunges out of the elevator, his claws out and licking its chops. Mary Jane screams at Aunt May to stay in the kitchen, while the Man-Wolf advances towards her. Leaning (terrified) against the wall next to the loft's fireplace, MJ grabs hold of the fireplace poker and slams the Man-Wolf with all her might, and then starts to run away. The Man-Wolf takes off after her and tackles her to the ground. He is on the verge of delivering the deathblow when Aunt May shows up and smashes a teapot filled with boiling water on his head. As the Man-Wolf shrieks in pain, Aunt May grabs MJ by the arm and pulls her to safety in the kitchen.

ACT 3: Meanwhile, at the Fantastic Four Headquarters, Spider-Man's spider-sense suddenly kicks in, warning him that something is wrong back home. Putting his shirt back on – he took it off so that Reed could do further testing – he rushes back to Avengers Tower, leaving the Black Cat to get tested more.

ACT 4: Back at Avengers Tower, Aunt May and Mary Jane have barricaded themselves in the kitchen and are protected by a defense systems that Aunt May activated. On the other side of the kitchen door, the Man-Wolf prepares to make his next move but is interrupted by a herd of Iron Men alerted by the distress signal activated when Aunt May activated the defense system in the kitchen. Within seconds, the Man-Wolf is neutralized. As the Man-Wolf transforms back into John Jameson, Spider-Man arrives on the scene, wondering what just happened.

ACT 5: Somewhere in the New York City sewers, the Lizard, recovering from his skirmish with the Black Cat, is tormented by memories. In his flashback, he recalls when he forcefully administered his bio-restorative serum to his son to cure him, which is what the rock told him to do (he was invited to study a meteor rock in Sensational Spider-Man #23). Tormented by those images, he lets out a roar, which echoes through the sewers and which reaches the ears of Vermin, who is feasting on the crooked cop-pimp he murdered in last issue. Vermin lets go of his victim and takes off towards the Natural History Museum. The Lizard takes off in the same direction.

ACT 6: Back at the Fantastic Four Headquarters, the Black Cat has had enough of being poked and probed so she takes off through a window.

ACT 7: Mary Jane and Peter are discussing the recent events in their lives and how both she and Aunt May have been experiencing bouts of extreme anger at one point or another over the last few days. As they continue discussing this, Peter dons his new red and gold costume, which offers more protection, and he then takes off into the night to go meet with someone who can provide him with some extrasensory help: Madame Web.

To be continued.