If comic-book movies have taught us anything, it's that on-call superpower is easy; off-duty vulnerability is hard. Never mind for the superheroes, I mean for the moviemakers. Too little introspection makes for two-dimensional cartoons and the triviality of ''Batman & Robin,'' but lay the Freud on too thick and we're left with the mopey neurosis of ''The Hulk.'' Among the countless feats of strength and grace executed by Spider-Man 2, the greatest may be that, under the direction of Sam Raimi and in the formfitting performance of Tobey Maguire in the title role, superhero and struggling young man are equally riveting, and wildly charming too. This triumphant sequel to the hard-to-top 2002 original may be the first great comic-book movie in the age of self-help and CGI wizardry, an entertainment in which both the thrills and the therapeutic personal growth are well earned.
When last heard from, Peter Parker (Maguire) had come to grudging terms with his extraordinary vocational calling and with the isolation his ''gift and curse'' exacts. He realized he could never reveal his secret identity to his beloved Mary Jane Watson (Kirsten Dunst, still the sweetheart most worth kissing while upside down), lest that knowledge put her in danger. He understood that he must hide his true self, too, from his dear old widowed Aunt May (Rosemary Harris). And certainly he had better cool it with his best friend, Harry Osborn (James Franco, still making the most of a smolder that foreshadows megalomania), whose grudge against Spider-Man goes back to the first movie's bad-guy conflict.
So, as ''Spider-Man 2'' opens, Peter Parker's got the blues, and got them bad. But only Raimi, perhaps, working from a script by veteran Alvin Sargent (and a screen story by ''Smallville'' creators Alfred Gough and Miles Millar and ''The Amazing Adventures of Kavalier & Clay'' author Michael Chabon), could locate the funny and tender undertones that make Spidey so beloved a Marvel hero. Parker's just a college kid, for Pete's sake, who has enough on his plate trying to juggle schoolwork (he's never prepared) and two part-time jobs (he can never pay the rent on time) even without interruptions to pull on the costume and save the world. His apoplectic publisher (J.K. Simmons, still a hilarious blowhard) at the newspaper where he moonlights as a photographer barks at him. And the guy at the pizza shop for whom he totes pies fires him because -- get this -- his deliveries are late! An entire Raimian universe is contained within the notion of Parker frantically fighting through the thickly webbed traffic of New York City, even resorting to Spidey ingenuity in desperation, only to deliver to a bored office receptionist who refuses to pay. ''Spider-Man 2'' shimmers with love of New York, love of boys on the verge of adult self-awareness, love of young love, and, most of all, brimming, happy, unaffected love of comic books.
And of comic-book villains. While Parker struggles with ambivalence, loneliness, resentment, jealousy (Mary Jane is now dating an earthly hero, i.e., an astronaut), and a shocking lack of laundry skills when it comes to mixing white garments with colors, Spidey has a splendid new nemesis to worry about: Dr. Otto Octavius -- a.k.a. Doc Ock (Alfred Molina, now inducted as one of the great baddies) -- is a good scientist turned rotten by a daring nuclear-fusion experiment gone monstrously haywire. And in his case, evil manifests itself in four flexible tentacles of menacing metal with destructive minds of their own (and tips resembling hungry ''Alien'' monster faces).
While Peter must struggle to incorporate his alter ego's good superpowers into a daily life he can tolerate, Octavius must struggle to free himself from the bad superpowers that have overtaken his will. Mary Jane must struggle with unquenchable feelings for the brooding cutie she thinks has rejected her. Aunt May must struggle with a whole lot of daily-life-in-the-city woes, including an inability to pay her bills. And Harry -- poor rich, deluded, misguided, spoiled, dangerous Harry -- well, he doesn't even know what troubles lie ahead.
''Spider-Man 2'' covers a lot of territory; the film is long. But it's light too, and lithe, and moves along with a narrative confidence that matches Parker's own advanced mastery of acrobatics as he loops and arcs on his appointed heroic rounds. (Maguire has reached a new level of arachnid loveliness.) When he doubts himself, Spidey finds that his spinning goo clogs up and becomes unreliable. But when he's happy, he sticks his landings perfectly. So does this movie.