In 2009, the Bulletin of the Atomic Scientists' clock is set at five minutes to midnight; the famous graph is used to suggest how close the world is to nuclear war. Contrast this clock with another round symbol, a blood-daubed smiley face: the perfect emblem of the Reagan years.

This clock and this inanely grinning button were the twin logos Alan Moore and Dave Gibbons used in their twilight-of-the-comic-book-gods graphic novel Watchmen (1986). There's nothing aged about Watchmen's sturdy mystery plot, its questioning attitude to force or its yearning for comfort in childhood stories in the face of Armageddon. While being a first-rate adaptation of the most serious fictional graphic novel ever, the film itself is probably a new classic of science fiction, although science-fiction films that go this large don't tend to be so morally complicated.

The action is set in a parallel world, where a group of costumed vigilantes became part of our national character right before World War II. Thus begins the rise of a brutally conservative America, which exists, in 1985, under Nixon's fourth term. The Cold War has been held in check by an American atomic Superman, an increasingly disassociative demigod known as Dr. Manhattan (Billy Crudup). He can explode people with a glance or crush tanks with a gesture. But now the Cold War seems ready to flare up, right after Dr. Manhattan has a public meltdown in front of ambushing TV cameras. He vanishes, leaving behind his longtime companion, Laurie (Malin Akerman), a minor former vigilante.

Less noticed among all this narrative is the brutal murder in Manhattan of a 67-year-old former CIA assassin (Jeffrey Dean Morgan); he was once a sort of arch-sadistic version of Captain America. This murder is investigated by a dogged but disordered masked man called Rorschach (Jackie Earle Haley) and his former partner, the movie's good cop, an essentially gentle figure who once bore the nom de guerre Nite Owl (Patrick Wilson).

Following this plot, and trimming the subplots, director Zack Snyder does a better job than anyone who saw 300 would have ever believed. The action scenes are as cleanly cut as Gibbons' panels. Snyder's real drawback is going rather too large with the violence. Yes, Rorschach's David Fincher-style moments of violence fit the story. But Nite Owl should have been the kind of character who disables villains long enough to subdue them, not the kind that cripples them for life.

The acting doesn't fail Snyder. Wilson's dweebishness, matched with the girlish salt of Akerman and seen through a restaurant window, has some of the charm of the Clark and Lois romantic scenes in Superman II. But you don't want an essentially untried actress having to plead the cause for the human race, as Akerman must at the end of the film.

Crudup conveys all the power and remoteness of a deity. Snyder borrows some very heavyweight film music to sum up the accident that unsticks Dr. Manhattan in time: "Pruitt-Igoe" from Philip Glass's Koyaanisqatsi.

Against this lineup, Matthew Goode's ambiguous genius figure Adrian Veidt comes in a bit wanting. Goode's similarity to comedian David Foley becomes impossible to ignore. Perhaps the most-missed scene from the book is Veidt scanning the world's TV stations and using the data to predicting the nuclear war to come. We don't get Veidt's contemplativeness, his watchfulness.

But then there is another serious drawback to Watchmen: Snyder focuses so much on superhumanity that humanity gets the short shrift. This could have been remedied during a rescue from a burning building. But we get less onscreen than Gibbons had on the page.

Incidentally, I saw Watchmen in a ratty urban theater, an old palace divided up decades ago and left to slowly rot. The 9:30am screening was proceeded by a lunatic movie ad for the National Guard. It insisted that a guardsman's life was a combination of Speed Racer and Sgt. Rock. A "song" by Kid Rock was belted out, claiming that Rock was a warrior "giving all of myself ... and you?" Und du? is the way the old Nazi propaganda poster put it. So Watchmen's "relevance" was ready-made, right during the inspired title sequence. We glimpse a girl sticking a flower into a National Guardsman's rifle during a protest. The gun goes off, leaving floating petals in the air.

WATCHMEN (R; 163 min.), directed by Zack Snyder, written by David Hayter and Alex Tse, based on the graphic novel by Dave Gibbons and Alan Moore and starring Billy Crudup and Jackie Earle Haley, plays countywide.

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