As the sequel to his first Spiderman role, Tobey Maguire is Peter Parker. He has been fighting crime and trying to figure out how to balance his life as Spiderman and his desire for a relationship with Mary Jane Watson, capably played again by Kirsten Dunst. Then mid-movie he has an identity crisis of sorts, discards his costume in the trash in an alley, and vows to give up his crime-fighting role.
But the call is too great, on the loose is Alfred Molina as Doc Ock , with four metal bionic arms attached to his back, powered by Tritium fuel. The risk to the city and the citizens is too great, he has to put his costume back on and save the city.
The romantic side story is MJ getting tired of what she sees as Peter's lack of commitment to their "friendship", e.g. repeatedly failing to show up to see her stage play. She in fact gets engaged to be married to another man. Somehow through all the turmoil MJ has to realize who Peter really is and that he is the only one for her.
Good, entertaining movie.