I got more ideas:
Connors is studying the lizards trying to get to understand them so he can get his missing arm once again. Meanwhile Jameson has just hired Mac Gargan to try to discover the true connection between Peter Parker and Spider-man. Gargan goes off searching for Parker and finds him in the park with MJ. The two are simply enjoying the cool summer day as Gargan keeps a watch on them. Peter feels like someone is watching them but decides to ignore the feeling.
Connors believes he found the correct formula to perfect his cure and injects himself with it. His missing arm grows back. At first the experiment was a success. Connors runs into Peter who is amazed at the fact he has both his arms. Connors informs Peter that his experiment has finally gone right and with no side-effects. Peter is happy for Connors who returns to his home. That night Connors undergoes a horrible transformation that makes him become the Lizard.
The Lizard storms out of his home and into the streets. Cars weave out of the way of the Lizard as the beast runs through New York. Peter arrives home to hear his radio talking about a giant lizard rampaging through the city. Peter suits up to become Spider-man but little does he know across the street on the rooftops stands Gargan with a camera taking pictures of Parker suiting off and swinging to face the Lizard. Gargan decides to follow Spider-man to get a few more pictures just in case.
Spider-man spots the Lizard at the park. Spider-man confronts the Lizard. Spider-man and the Lizard face off at the park. The Lizard manages to escape through the sewer. Spider-man doesn’t go after him. He spots a flash from the bush and uses his web to pull out Gargan. Spider-man breaks his camera before swinging off. Gargan reports to Jameson that Peter is Spider-man but Jameson laughs at his claims and decides that Gargan can’t bring up the evidence so he fires him.
Gargan begs for another chance so Jameson decides to allow him to test out a new battle armor to discover the identity of Spider-man. Gargan went through the transformation to become the Scorpion. Peter arrives at Connors home eager to see how the success of his serum went. Peter finds the door busted open with Connors’ wife Martha shocked. Martha tells Peter that Connors transformed into a terrible beast late last night.
Peter puts one and one together and sees that the Lizard was Connors. Peter looks through his notes and realizes that there is an antidote just in case something like this happens. Peter takes some of the antidote and heads off. He suits up to become Spider-man again and swings off to hunt down the Lizard. While he was out and about the Scorpion ambushes Spider-man. The Scorpion wants to bring Spider-man to Jameson unmasked.
Spider-man fights the Scorpion and manages to defeat him. Spider-man pays no attention to the fallen Scorpion and instead heads down into the sewers to search for Connors. Gargan returns to Jameson who failed at getting Spider-man. Jameson, angered at Gargan, fires him. Gargan becomes insane at that point and knocks Jameson into the wall. Gargan goes to kill Jameson but Jameson convinces him that everything will be alright if he brings Spider-man to him.
The Scorpion heads off to hunt down Spider-man. Spider-man finds the Lizard within the sewers and tries to inject him with the antidote. The Lizard doesn’t want the antidote and so a battle soon erupts between the two. Before long the Scorpion arrives on the scene and attacks Spider-man. Spider-man is between two villains; the Lizard and the Scorpion fighting for his life. The fight is soon taken back to the surface as the Lizard tries to escape.
Spider-man blocks the Lizard’s escape path but is attacked by the Scorpion. Spider-man is taken down as the Scorpion claims victory. Connors begins to take control as the mask is removed to see that Spider-man is Peter. The Lizard attacks the Scorpion in an attempt to save Peter. Spider-man comes to as he sees the Lizard attacking the Scorpion. Scorpion is thrown into the river as the Lizard allows Spider-man to inject him with the antidote.
Connors returns to normal as the Scorpion surfaces again. Spider-man fights the Scorpion. Connors sees a fallen power line and yells to Peter that shocking him may cause the suit to lose its power. Spider-man manages to knock the Scorpion into the power line and it does as planned; but to a greater extent. Trying to escape the lighting Scorpion takes a step forward putting his foot into some water causing the lighting to flow to three cars surrounding the Scorpion.
Spider-man grabs Connors and swings out of the way as the cars explode killing the Scorpion. Connors returns home to find Martha waiting for him. Peter finally asks MJ to marry him which she agrees to. Time passes and then comes a knock on the door. Connors opens it up to find Eddie Brook, Jr. standing at the doorway. Connors ask him what he wants and Eddie simply replies, “you have something that belongs to me.” (because during Spider-man 3 Connors had a sample of the sym.)