A "Zodiac" of many colors

The most intriguing thing about a film dominated by a few men obsessing over a murderer is how decidedly unmorbid it is.

Half thriller, half dramedy, "Zodiac" centers on the lives of an editorial cartoonist (Jake Gyllenhaal), a detective (Mark Ruffalo) and a journalist (Robert Downey Jr.), connected by their various quests to find Zodiac, the self-dubbed serial killer who terrorized the San Francisco area in the late 60s and early 70s. Though Zodiac is at first a routine write-up, he soon becomes an obsession for the trio as he continually blackmails area newspapers into printing cryptic codes containing clues to his identity. Drawn to the codes, the investigators pour themselves into the mystery, which remains, to this day, unsolved.

With a deserving story on his hands, director David Fincher ("Panic Room," "Fight Club") has produced another captivating thriller that is admirable in its sheer entertainment value. Clocking in at 158 minutes, "Zodiac" is not exactly a typical 90-minute popcorn flick to watch leisurely on a Saturday afternoon. Instead, it is a thoroughly developed, alarmingly fast-paced model of well-done storytelling, where differing plotlines are seamlessly intertwined to form a rare, satisfying film.

Fincher is relentless as he captures each suspect, each victim on film to form a complete story. While he is at times overly graphic in his murder scenes, the scenes remain classy, never lowering to blood-and-gore standards. Most of the thrills in this film are psychological and not measured by quarts of blood splattered shamelessly on victims.

Not only does Fincher have a worthwhile story, he has a sparkling cast to match. Of the three, Downey, as crime reporter Paul Avery, is the scene-stealer. His ruggedly unshaven, Johnny Depp-esque features perfectly echo his hand-waving, chain-smoking, alcoholic behavior.

As a fast-talking reporter, Avery the character isn't really a new concept. Journalists in film stereotypically have a tendency to talk like auctioneers (the editor in "Spiderman"), but Downey manages to make his character look unique with his little cheeky mannerisms, the way he pronounces the word "looming" and his charisma as he stalks around the newsroom. Downey matches the film — fast-paced and somewhat insane with more than a little sardonic sarcasm.

If Downey complements the film's surface, then Gyllenhaal is its heart. This is a man who, at first, drives his son to school every day to help ensure his safety, but later becomes so obsessed with Zodiac that he ruins his marriage and turns his apartment into a filing cabinet for old police reports and newspapers to further his search. Gyllenhaal captures the essence of the quiet, muttering Robert Graysmith, whose existence seems dependent on unveiling the identity of Zodiac. All Graysmith wants is to be able to look Zodiac in the eye and know that it's him, a desperation Gyllenhaal portrays heartbreakingly well.

Though the acting is first-rate, the best part of the film is its speed. Despite its epic running time and morbid subject, "Zodiac" is lively and witty, comfortably packed with dark humor. Ruffalo's David Toschi, whose incessant need for animal crackers is the running joke of the movie, has more than one occasion to showcase his wry humor. And when Avery and Graysmith discuss coding procedures, Avery doesn't hesitate to make fun of Graysmith's feminine blue-hued alcoholic drinks. Such moments help "Zodiac" avoid lumbering about like similarly-themed films that take themselves too seriously, like "Signs," and just about every recent horror movie released.

This is where Fincher makes some very good calls. He realizes that yes, the film is about people dying, but there is no need for the audience to sleep like dead people either. And what a thankfully good decision that was.

But there are times when "Zodiac" falters — regardless of how quickly a movie moves, 158 minutes is just too long. The screenplay would have benefited from some editing and trimming towards the beginning. The long setups and longer elaborations can leave viewers staring at their watches, waiting for a moment of comic relief to diffuse the ample suspense.

Despite its shortcomings, though, "Zodiac" provides more than its share of entertainment. Perhaps it is the serious nature of the story, but upon leaving the theater, viewers will probably feel like they witnessed something important. Viewers can sympathize with the San Francisco-area residents, especially those who lived in the Washington, D.C. region during the sniper shootings of a few years past.

"Zodiac" is not destined for true film-infamy, like "The Silence of the Lambs," but it's perfectly good just as it is.

"Zodiac" (158 minutes, wide release) is rated R for some strong killings, language, drug material and brief sexual images.