During his patrol, Spider-Man stops a group of thieves who are breaking into a bakery. Peter manages to snap some pictures to try and sell to the Daily Bugle. He happily leaves and makes it back home in time for his curfew (although Aunt May points out that he only made it back with seconds to spare), but discovers after developing his photos that he has messed them up.
Meanwhile Dr. Curt Connors injects himself with the lizard serum (that had unknowingly been amplified by Electro) to regrow his arm. He awakes in pain, and his arm indeed regrows, but knowing that he experimented on himself, his wife, Martha, is furious that Curt used an untested formula on himself. Curt brushes away her worries and rejoices with Billy.
At school, Peter is attacked with water balloons by Flash Thompson and Kenny Kong, which he dodges until he realizes it might reveal his secret identity as Spider-Man. Gwen steps in and gets everyone to laugh at Flash instead by taunting him about a foul-up during a past football game. Gwen and Peter go to the Connors lab, and Peter begins complaining about his problems, only for Gwen to tell him to stop pitying himself. They enter the lab, thinking they're going to help Eddie clean up from the battle with Electro.
Curt reveals that his arm has grown back and they celebrate until they realize scales are growing on his arm and back, determining that the reptilian half of his brain his taking over and Curt is slowly regressing. Going over Curt's notes, the group decides that a gene cleanser is the way to go. This new formula will block out any non-human DNA and keep Curt human. Peter muses that this could also take away his spider-powers, before he realizes that Billy has overheard everything. Peter tries to comfort Billy, but his speech about how his father will always love Billy is interrupted by Curt's cries of pain. Horrified, Curt admits that he's made a mistake as his mutation accelerates and he transforms into the Lizard. Martha tries to communicate with him, but Curt's brain is now primal, and he trashes the lab and flees.
While Eddie goes in pursuit, Peter pulls the "Aunt May will ground me" excuse and goes after Connors as Spider-Man, tracking him to Grand Central Station. Trying again in vain to communicate with him, Spider-Man and the Lizard tackle each other into a subway tunnel where the Lizard bashes Spider-Man's hand with his powerful tail. Hastily webbing up his hand, Spider-Man pursues the Lizard along a train car, but the Lizard pushes him through the ceiling and into the car. Dazed, Spider-Man's head is nearly bitten off when a spunky old lady whacks the Lizard with her handbag, distracting the Lizard and buying Spider-Man time to regain his senses and shove the Lizard back outside of the car, where they continue fighting. Finally, Spider-Man falls off the train, and tries to catch the train with a web. Unfortunately, he hits the Lizard's tail with the webline, which the Lizard rips through and Spider-Man tumbles to the tunnel floor as the Lizard escapes.
Martha and Gwen finish the gene cleanser. Martha points out that the Lizard's hide is too thick to inject it, so it will have to be administered orally. Spider-Man returns to the lab at this point and volunteers to administer the cure. Conveniently, Eddie calls in and informs them that the Lizard is prowling around the Bronx Zoo. Spider-Man takes off in pursuit with a vial of the cleanser. Martha plans to follow and leave Gwen with Billy, but Gwen discovers that Billy is gone, apparently having listened in on the phone call.
Spider-Man meets up with Brock, who tells him that the Lizard has gone into the World of Reptiles building. After mistakenly wrestling an alligator, Spider-Man is attacked by the Lizard and nearly drowns, but is saved by another alligator distracting the Lizard. The Lizard throws Spider-Man back up to the surface, and Eddie to pulls him out. They come up with a plan to trick him into the polar bear pond. Eddie volunteers himself as bait and finds himself being chased by the Lizard right into the trap. They almost succeed when the Lizard is alerted by Spider-Man's cellphone ringing. The Lizard and Spider-Man fight some more, and then Billy shows up and tries to talk some sense into his father. The Lizard is about to snap Billy up, but Spider-Man leaps in to get the Lizard into the pond. Spider-Man pours the cleanser into the Lizard's mouth, using Billy's skateboard to keep it open wide. Thankfully, the cleanser is a success, and Curt returns to normal, his arm lost once more. And off in the distance, a webbed up camera flashes.
The next day, Peter gets the Lizard photos published in the Bugle and gets the money he needs. However, when Gwen, Eddie, and the Connors' find out, they are outraged that he ran off simply to take pictures. Although Curt is forgiving, considering his own fault in the mess, Martha tells Peter that he has lost her trust and fires him from the internship. Just after Peter leaves, an unseen web-line grabs another vial of gene cleanser. When Peter returns home, he contemplates taking it to get rid of his powers, but decides against it and hides it in his room.
This episode provides examples of:
- All for Nothing: The pictures Peter took of himself stopping criminals turn out horribly thanks to the camera picking up the flash from the window, meaning he has nothing to sell to the Bugle.
- Analogy Backfire: From Curt and Martha's discussion:Curt: Some lizards regenerate lost limbs.
Martha: And some lizards stick to walls and eat raw meat! - Armor-Piercing Question: Peter, when he realizes that Billy's overheard what's happening to his father, tries to comfort the kid. But Billy asks a question Peter can't answer.Peter: Trust me, your dad will always care about you.Billy: Even if he turns into a monster?
- Badass Bystander: The old woman who saves Spider-Man by beating the Lizard with her handbag.
- Be Careful What You Wish For: Curt just wanted his arm back. Well, he got it... along with a tail, a thick scaly hide, razorsharp teeth, and a taste for human flesh.
- Bittersweet Ending: Curt is cured of his Lizard condition thanks to a Gene Cleanser. Unfortunately, because Peter abandoned the team when they needed to make said cure and took a picture of the event and sold it to the Bugle, he loses his internship, and to make things worse, this begins Eddie's Start of Darkness. A frustrated Peter steals another vial of the Gene Cleanser and is tempted to rid himself of his spider DNA, but carries on because he remembers his "Great Power/Great Responsibility" mentality, which saved the Connors in the first place.
- Body Horror: Curt's transformation into the Lizard is unpleasant to say the least.
- Calling Card: The classic "Courtesy of Your Friendly Neighborhood Spider-Man."
- Death Seeker:
Word of God is that Eddie Brock is one deep down, which leads to him following the Lizard so closely and volunteering himself as bait. - Even Bad Men Love Their Mamas: Or great-aunts in the case of the thugs robbing the bakery. Not that it stops them from robbing the bakery owned by their great-aunt. Spidey is quick to call them out on it.
- Gone Horribly Right: Connors only used the lizard formula to try and grow his arm back. It worked... and also mutated his DNA to the point that he became a giant lizard man that attacked New York, and likely would have killed numerous people if Spider-Man hadn't intervened.
- Harmful to Minors: Billy has to watch his father turn into a rampaging, monstrous lizard who tries to eat him.
- Hypocritical Heartwarming: One of the robbers tells his partners not to eat anything from his great aunt’s bakery they are stealing from.
- I Am a Humanitarian: The Lizard tries to eat a bystander during his fight with Spider-Man, and almost bites Spider-Man's head off.Spider-Man: Sorry, pal, no eating in the subway.
- "I Know You're in There Somewhere" Fight: Billy attempts to talk his dad down from his supervillain persona. If at all, it works for only a second...which is long enough for Spider-Man to show up and protect the kid.
- I Need to Go Iron My Dog: Peter gives one of these by saying that he needs to go home (despite the Lizardy-Connors situation), something that earns him ridicule from Mrs. Dr. Connors and Gwen. It comes back to bite him the next day when everyone thinks he made the lame excuse so he could take pictures of Spider-Man's battle with Connors and sell them to the Bugle.
- Mood Whiplash: The celebration of Curt's regeneration formula working followed immediately by the urgency of stopping his transformation.
- No Good Deed Goes Unpunished: Peter loses his internship after leaving his friends to save Curt as Spider-Man. The fact that his desperate attempt to win prize money to help Aunt May with the bills doesn't help at all since his credited photo of Spidey and the Lizard frames him as being selfish, and there is some implication that he is in bigger trouble with Aunt May since he didn't answer his phone that night.
- No Ontological Inertia: Curt loses his arm again when he reverts to being human. Losing the tail probably counts too.
- Painful Transformation: See Body Horror.
- Pet the Dog: Randy helps Gwen defend Peter when Flash and Kenny were throwing water balloons at him.
- Pie in the Face: The bakery thugs get this Spider-Man style.
- So Much for Stealth: Thanks a lot Aunt May.
- Spared by the Adaptation: Unlike the comics and other depictions, Connors' lizard problem is cured in the same episode it occurs, and the Lizard never resurfaces.note
- Start of Darkness: This episode begins Eddie's resentment of Peter after he deserts the internship team in their hour of need and sells a picture to the Daily Bugle and he becomes furious.
- Tender Tears: Martha briefly sheds a few after Curt touches her face with his regrown hand, overjoyed that her husband has it back.
- Tragic Monster: Connors only wanted his arm back, he didn't ask to be turned into a mindless monster and attack his family and interns.
- With Catlike Tread: Overlaps with So Much for Stealth, but Spider-Man attacking an alligator really wasn't the best idea in hindsight.
- You Need a Breath Mint: "Yikes! Can you say halitosis?"
