Of course, Fincher is still Fincher, so it's not as if any of this plays as dry or bureaucratic. Scene by scene, Zodiac is the director's most visually restrained work to date, taking its cue from the mostly functional mise-en-scène of the police procedural; at the same time, he can't resist the occasional expressionistic flourish, as when two young lovers en route to violent death drive slowly down a quiet Vallejo street as fireworks explode overhead. (The Zodiac's second attack took place on July 4, 1969.) Nor will you ever again be able to listen to Donovan's loping "Hurdy Gurdy Man" without a chill running down your spine, assuming that you can now. The actors, for their part, do a credible job of creating the necessary illusion that they're playing human beings rather than walking, talking DSM-IV codes: Downey turns Avery, who received several personal communiqués from the killer, into his standard hilarious motormouthed cynic, while Ruffalo, playing the real cop who inspired Steve McQueen's character in Bullitt, expertly mimics Toschi's shaggy, understated demeanor.
Gyllenhaal is the weak link, projecting little more than dogged earnestness—but then, I think the movie erred in selecting Graysmith as its source and nominal protagonist. Zodiac buffs know well that the true obsessive is a fellow named Gareth Penn, whose untenable yet mesmerizing theory maintains that various odd misspellings in Zodiac letters—"phomphit" in lieu of "puff it"; "cid" instead of "kid"—are part of an elaborate mathematical code. It's also unfortunate that Zodiac follows Graysmith in making a determined case against Arthur Leigh Allen (John Carroll Lynch), a convicted child molester who died in 1992. Plenty of circumstantial evidence points to Allen, but it's still a bit odd that the movie—like Graysmith's second book, Zodiac Unmasked—concludes with one of the Zodiac's surviving victims identifying Allen from a photo lineup (over 20 years after the attack), while the fact that Allen was conclusively ruled out by DNA testing a few years ago is relegated to a end-credit footnote. Wasn't this supposed to be a film about uncertainty leading to madness? Caught up, like so many others, in the thrill of the hunt, the movie ultimately falls into its own trap.