Strangely, Peter Parker (Tobey Maguire) is happy and doing well. Spider-Man is loved by New York, Peter is loved by Mary Jane (Kirsten Dunst). But Harry (James Franco) still believes Spider-Man killed his father, seeks revenge, and now he has the power of the Green Goblin. He Attacks Spidey in mid-air and loses the fast-paced battle, falling into an alley from a great height. Peter takes him to the hospital and learns that Harry has lost his recent memory. They are friends again.
But the New Goblin is not the only super-villain to worry about. Petty criminal Flint Marko (Thomas Haden Church) escapes from prison to see his family. Fleeing from the police, he enters the Particle Physics Test Facility, where he is fused with the sand, becoming Sandman. This is a great super-villain: basically a sentient pile of sand, who can slide under doors and into air-ducts, create pile-driver arms, and blow away in a dust-cloud--powers useful for robbing armored cars. I love this guy: most comic-book antagonists are billionaire arms-manufacturers or brilliant scientists, but Sandman is one of the rare working-class super-villains, and his back story makes us sympathize with him despite his destructive potential.
Then things begin to go terribly wrong for Spider-Man. Mary Jane loses her acting job just as Spidey is becoming popular with the public. In a terrific rescue far above the city, he saves the life of his fellow student Gwen Stacey (Bryce Dallas Howard) and in a publicity set-up kisses her the same way he had first kissed Mary Jane. When Peter learns that Marko was responsible for Uncle Ben's death and the struggle becomes personal, he begins to lose himself.
Spider-Man goes dark, literally. A symbiote from outer space finds and merges with him in a story direct from one of the most popular Spider-Man comics. He becomes more powerful, more angry and self-centred, less compassionate. When Harry regains his memory and forces Mary Jane to abandon Peter, he goes off the deep end. We watch him become not only dangerous, but a ridiculous jerk. Eventually he rips off the black symbiote's tentacles and web, but they attach themselves to rival photographer Eddie Brock (Topher Grace) creating another super-villain--Venom.
Much of the personal story has been a bit slow, but the climactic battle in the skies over New York includes Spider-Man, The New Goblin, Venom, and Sandman. It is a huge battle, with Sandman a monstrous Titan and Venom a slavering, horrific alien monster. The movie has been criticised and even sited as a third episode failure, not only for the teen angst story, but for the crowded showdown. But I think the latter criticism misses the point. There are actually four potential heroes or villains in the end because Spider-Man was becoming evil himself and the others were at one time worthy of our sympathy. In Marvel fashion, heroes turn into villains and back again and each faces a different fate. The point is that any one of us can be a hero or a villain depending on our fears, our choices, and our moral strength.