The movie opens on the mystery of Peter Parker's parents' death. They are running for their lives, taking their secret work for Oscorp with them on the plane. A crewman pulls a gun, there is a struggle, Peter's mother (Embeth Davidtz) is killed, his father (Campbell Scott) sends a secret message just before the plane crashes.
Spider-Man (Andrew Garfield) is swinging through the skies over New York because an Oscorp truck carrying plutonium has been hijacked and is smashing its way up the Avenue. The perps are soon hanging from webs as Spidey chases plutonium containers that are flying about the street. In the middle of this, his girlfriend Gwen Stacy (Emma Stone) phones him because he is late for graduation.
Max Dillon (Jamie Foxx), a nerdy scientist with an armload of blueprints, is nearly hit by a flying vehicle, but Spidey saves him. He develops an obsession with Spider-Man. At Oscorp, where he works (doesn't everyone?) he rides up the elevator with Gwen. He raves about how wonderful Spider-Man is, but she and Peter have just broken up. He keeps seeing her dead father, whom he had promised he would stay away from Gwen, for her safety.
Harry Osborn (Dane DeHaan) Norman Osborne's son, visits his father on his deathbed. He is dying of an inherited disease and Harry, though he inherits the company, is doomed. Max Dillon, getting no respect as usual, has to stay late to fix an electrical problem. He is electrocuted and falls into a tank of electric eels. Harry meets with the board of directors and threatens them all. Peter, his old friend, comes to see him to express his condolences and tells him about Gwen.
In the morgue, Max Dillon awakens, shooting blue flame. He wanders the city streets looking for electricity to feed on. His skin is blue and his eyes glow. Spiderman and a lot of cops confront him in Times Square. He can lift trucks, toss cars, shoot lightning, but Spidey eventually ties him down. Peter is investigating his parents' research, and so is Harry. He wants some of Spider-Man's blood to cure himself, but Spidey, knowing how dangerous it is, refuses.
Gwen is searching the Oscorp files for Max Dillon, who seems to be a non-person now, and Oscorp spies are alerted. At the Ravencroft Institute for the Criminally Insane, Doctor Kafka (Martin Csokas a bit over the top), is torturing Max Dillon, who calls himself Electro now. Oscorp, it seems, still has the spider venom that created Spider-Man and the Green Goblin artifacts of Harry's father.
Electro is set free. The Goblin and Electro, who both feel they have been betrayed by Spider-Man, set out to take down Oscorp, Spidey, and New York.
The tragic end is true to the comic book, and no doubt many fans would have complained if it was changed, but I don't have to like it. The denouement is set up for two planned sequels that never happened. There is much to like in this: spectacular fights and special effects, some damn fine acting particularly by Andrew Garfield, and some genuine heartfelt chemistry with Gwen and Aunt May, but one can be forgiven for thinking, "What? Another Goblin? I've already seen three movies about him."