They're back. And once again they're up to their mutant eyeballs in trouble.
This time around, the X-Men, those Marvel comic heroes whose mutant genes give them both super powers and super headaches, must try to prevent the world from plunging into a war pitting humans against mutants.
This sequel wants to know: Can't we all just get along here?
The answer, of course, is no. Anyone who reads today's headlines knows that. So does anyone who ever picked up a Marvel comic book or saw the original "X-Men" movie.
This time around the fun begins at the White House, where a dragon-like, vaporizing mutant invader breaches security and comes within a whisker of impaling the President of the United States to his desk. He leaves behind a dagger and a demand: MUTANT FREEDOM NOW.
This intruder, we soon learn, is a reptilian German mutant with yellow eyes and low self-esteem named Kurt Wagner (Alan Cumming). His act serves only to inflame the anger of the world's humans against its normally invisible mutant population.
While amusing, this Teutonic circus freak is not the most important addition to the cast. That honor goes to William Stryker (Brian Cox), an oily government operative who uses the attack on the president to get authorization to wipe out the world's mutant population.
To do this, however, he needs to tap into a super-computer called Cerebro, which can locate every single human and every single mutant. The only person who knows how to operate the computer is benevolent Prof. Charles Xavier (Patrick Stewart), who is still running his school for gifted children - of the misunderstood mutant persuasion.
We soon learn that Stryker has an added ax to grind. His son once attended Xavier Academy - and wound up a drooling, wheelchair-bound mess. Striker will never stop blaming Xavier.
But this is not a simple humans vs. mutants face-off. Further complicating matters is the human-loathing mutant Magneto (Ian McKellan), who lives in a plastic jail cell - until he is rescued by shape-shifting Mystique (Rebecca Romijn-Stamos), a blue-skinned knockout who can assume anyone's identity in a split second. It's always a pleasure to watch her work.
So the real battle shapes up less as humans vs. mutants than as peaceable mutants on the one hand vs. war-mongering mutants and humans on the other. With much of Iraq now in rubble and the real president setting his sights on North Korea and Iran, "X2"'s anti-war sentiment possesses a timely potency.
It also has a heart. There are numerous subplots about teenage anxiety, unrequited love and the timeless search for our true origins. All mutants are outcasts, and they all suffer accordingly.
Rogue (Anna Paquin), who drains the life force out of anyone she touches, is having trouble figuring out a way to kiss Bobby, whose frosty breath can turn anything into a block of ice. It looks like abstinence is their hellish destiny.
But no one is suffering worse than Logan, a.k.a. Wolverine (Hugh Jackman), the star of the original "X-Men" who returns to Xavier Academy just as the hostilities with Stryker and the U.S. government are breaking out.
Logan, still rippling with muscles and armed with those deadly titanium claws that emerge from his knuckles, obviously hasn't gotten over his infatuation with Jean Gray (Famke Janssen), the telepathic bombshell. Unfortunately, she has married Scott, a.k.a. Cyclops (James Marsden), and after sneaking one kiss with Logan, she pulls back. Her sense of duty conquers both her yearning and her regrets. Wolverine takes his wounded heart and tries to find out what really happened when he first sprouted those deadly claws.
Screenwriters Michael Dougherty and Dan Harris keep these subplots boiling just beneath the surface of the main action, and the director, Bryan Singer, works hard to keep things moving at a gallop. The movie is more than two hours long, but the time tends, quite literally, to fly.
Though "X2" doesn't stint on the special effects - there is aerial combat, a dam collapse, numerous exhibitions of supernatural powers - its main focus is the humanity in the mutant heart.
These creatures, so vilified by the human race, are capable of lofty and venal acts - of love, jealousy, yearning, loyalty, revenge and sacrifice. It gives the movie, for all its comic-book aura, a grounding in the things that make us human. And it serves as a timely reminder that war is never the answer.