Are mutants born or made, and should they be cured?

Is individuality always a blessing, or can it be a curse? At what point does diversity threaten to lead to social unrest? Do people covered in blue skin and fur really read while hanging upside down by their feet?

These and other weighty issues are addressed with much verve and little restraint in X-Men: The Last Stand, the thoroughly enjoyable mutant-palooza conclusion to the X-Men series. A popcorn movie that has just enough subtext to keep it from spinning off into complete silliness, X3 won't be sweeping the Oscars next year, but it sure should fill some seats this summer.

Much has been made about the midstream change of X directors, from Bryan Singer (who did the first two films and then left to do Superman Returns) to the dreaded Brett Ratner (the Rush Hour movies). But aside from a few clunky moments, Ratner doesn't really botch things up. By the time he came on, these mutants were already on a moneymaking rampage and pretty much all he had to do was get out of the way and let the machine roll on.

That machine, of course, has to do with a newly evolved type of human, mutants who have special powers. As in the first two X-Men films, there are the good mutants who labor to get along with a mankind that fears them, and there are the bad mutants who simply and somewhat shortsightedly -- Who will mow their lawns? Who will bus their tables? -- want to crush their inferiors.

In X3, human scientists have come up with a cure for mutants, a drug that will make them revert back to their human states. This enrages the bad mutants, led by Magneto (Ian McKellen), who see it as a move to wipe out their kind. Other mutants, though, such as Rogue (Anna Paquin), a young lady who kills uncontrollably with just a simple touch, see the cure as a potential saving grace (not to mention a sure-fire sex aid).

No matter, it gives the screenwriters a chance to build toward a good mutant vs. evil mutant battle that rocks in a way nothing else has onscreen this year. It also gives them ample excuse to infuse the movie with all sorts of characters who were nowhere to be seen in the first two films.

In fact, new mutants show up at such a dizzying pace that they never acquire names, or else their names just don't sink in, so the audience is left to dub them whatever springs to mind. There's Porcupine Boy and Thunderclap Goth Androgynous Person and Really Fast Hot Chick and a horde of others, all colorful, bizarre and perfectly appropriate for a summer flick.

The two new good (X-Men) mutants who do matter are the aforementioned blue-furred Beast (Kelsey Grammer ) and Kitty Pryde (Ellen Page from Hard Candy), a young lady who probably has a supername but nobody bothers to use it, Kitty being kind of a cute moniker on its own. Kitty (who was played in brief spots in the prior movies by other actresses) is able to pass through solid objects, and her power is apparently contagious, so she's a good person to hold onto when you're about to get hit by a train.

Beast, on the other hand, is fully physical while simultaneously being the most intellectual of mutants. Gifted with super strength and agility, he works as a diplomat between mutants and humans. Casting Grammer here was an inspired decision as he simultaneously brings both humor and gravitas to the role, playing a monster whose mind can't accept his body.