In theaters

THE SIMPSONS MOVIE, directed by David Silverman, written by Matt Groening, James L. Brooks, Al Jean, Ian Maxtone-Graham, George Meyer, David Mirkin, Mike Reiss, Mike Scully, Matt Selman, John Swartzwelder and Jon Vitt, 86 minutes, rated PG-13.

In “The Simpsons Movie,” Earth is at stake – never mind just Springfield – and who better than Homer, Marge, Bart, Lisa and Maggie to come to its rescue?

Okay, so it’s best not to answer that question, particularly since it’s Homer and his new pet pig, Spider-Pig, who ignite the crisis in the first place.

Wearing its environmental heart on its sleeve, “The Simpsons Movie” arrives in theaters with a timely message in hand – the world is choking on our fumes, trash and pig poop, folks, and the future looks grim. Given its subject matter, some might think the movie was directed by Al Gore, perhaps after stopping by for a smoke on the set of “Weeds,” but no.

In fact, the film’s director is David Silverman, who works from a script written by no fewer than 11 writers, among them creator Matt Groening, whose Fox television series on which the movie is based is one of pop culture’s great success stories.

Now, after 18 years on television and 400-plus episodes in the can, it’s safe to say that Groening and his team got most of the kinks out before heading to the cineplex. It’s the kinks they’ve retained that makes the movie as fun as it is.

In its most streamlined form, the film, which begins with the ingenious inclusion of an “Itchy and Scratchy” short, finds Lake Springfield in a state of toxic disarray. Lisa (voice of Yeardley Smith) is on a campaign to raise awareness about how the careless actions of many are ruining the lake and, by extension, the planet itself. As she sees it, we’re all faced with “An Irritating Truth” and it’s time to do something about it.

With the exception of her new beau, a young Irish lad whose father, he insists, is not Bono, nobody listens to Lisa, least of all Homer (Dan Castellaneta), whose relationship with his new pet pig borders on the questionable, if not the obscene.

When Marge (Julie Kavner) asks what he’s doing with the pig’s droppings, he takes her to the huge silo he constructed in the back yard, in which molders the answer. Charged to get rid of it, Homer takes the silo to the lake, dumps it in spite of the countless warning signs not to do so, and unwittingly unleashes the sort of ecological blunder that changes fish into mutants, and which also catches the attention of the EPA.

Now quarantined beneath a glass dome, Springfield is in a state of chaos, with Homer the hapless target of the townspeople’s wrath. The rest of the movie is about the Simpsons’ efforts to break free from the dome (they go to Alaska) and then, in an effort to save Springfield, to break back in and make things right.

What ensues is a good movie that doesn’t best the series’ best episodes, but moments do come close. Silverman and company have crafted a careful balancing act designed to give audiences what they want – Homer making a fool of himself, Bart (Nancy Cartwright) up to no good, Marge overwhelmed, Lisa bulldozing forward for a good cause – while also working in favorite characters from the past.

It’s all just enough – just enough for most fans, who likely will dig seeing Bart nude, and just enough for the casually curious, who now might be tempted to do what Fox really wants them to do – buy all those boxed sets of the television series awaiting them on DVD.

Grade: B+

On DVD

ZODIAC, directed by David Fincher, written by James Vanderbilt, 160 minutes, rated R.

David Fincher’s meticulous, nearly three-hour film is about the quest to bring down the serial killer Zodiac, who wreaked havoc on Northern California in the late 1960s and early ’70s.

The effort to capture him was formidable, but since the killer was never caught, there’s the sense going into the film that perhaps Fincher will pull an Oliver Stone and close the books with his own theories.

He doesn’t. Instead, he follows information already presented in Robert Graysmith’s two books based on the Zodiac case. As such, there is no payoff in the telling, no fresh ideas, and the movie’s ending, as a result, is unsatisfying.

Some of the acting follows suit. Fincher demanded up to 70 takes on each scene, which is a good reason why so many of the performances seem drained of life. As Graysmith, the San Francisco Chronicle political cartoonist who became obsessed with the case after it was abandoned, Jake Gyllenhaal is especially flat; you can feel his fatigue, which becomes ours.

Fairing better are Mark Ruffalo and Anthony Edwards as detectives Dave Toschi and Bill Armstrong; they have an easy, believable give and take. Dermot Mulroney and Chloe Sevigny are wasted in dull supporting roles, though Brian Cox sparkles in a cameo as defense lawyer Melvin Belli.

The film’s memorable performance comes from Robert Downey Jr. as Paul Avery, the Chronicle reporter who covered the case. Downey came to the part sheathed in mischief, which gives his scenes a bounce they otherwise would have lacked.

In the end, “Zodiac” is a movie of interiors – newsroom, the home, the police department. All are effectively captured. But the movie errs in that it fails to mine any sense of public anxiety, as Spike Lee did, for instance, in his superior 1999 film, “Son of Sam.” In “Zodiac,” it’s as if these murders happened in a vacuum.

Grade: C

Visit www.weekinrewind.com, the archive of Bangor Daily News film critic Christopher Smith’s reviews, which appear Mondays and Fridays in Lifestyle, weekends in Television as well as on bangordailynews.com. He may be reached at Christopher@weekinrewind.com.