Werner Herzog's Bad Lieutenant: Port of Call New Orleans opens with the image of a snake swimming through the flood waters of New Orleans, and you'll have go a long way to find a more apt metaphor to kick off a picture with. What follows is a wholly indescribable mishmash of the slick and the stank, the cool and the campy. It is, at risk of putting too fine a point on it, almost exactly the film you'd expect Herzog and Nicolas Cage to come up with together.

What it is not is a sequel, remake, "reboot," or "re-imagining" of Abel Ferrara's 1992 film Bad Lieutenant. It is a different story, about a different guy, in a different place, and told in a completely different style (Ferrera's film is a stark, gritty, grim character study, and Herzog's picture, while frequently disturbing, plays as a pitch-black comedy). All it has in common with its namesake is that it is about a thieving, whoring, druggie cop; the carryover of the title (reportedly at the insistence of the two films' shared producer Edward R. Pressman, who wanted a straight remake and should have known better if he was hiring Herzog) will probably confuse more than it will assist.

The story begins in the immediate wake of Hurricane Katrina, as New Orleans cops Terence McDonagh (Cage) and Stevie Pruit (Val Kilmer--nice to see him in a theatrical release again) survey their deserted station house and discover a leftover prisoner who is about to drown in the rising flood waters of his cell. They contemplate betting on how long it'll take the water to kill the poor sap, but McDonagh ends up diving in to save him, hurting his back in the process. "I'm gonna write you a prescription for Vicadin," his doctor tells him, and our junkie cop is off and running.

Six months later, McDonagh is in the throes of a full-on drug addiction, tooting up in his car on the way into a crime scene. The scene is the gruesome, execution-style slaying of a family of five; the patriarch was apparently a low-level drug dealer. Solving the crime becomes, in his words, his "primary purpose"--well, that and getting drugs. Lots and lots of drugs.

Broadly speaking, we find Herzog working within the framework of a glossy, well-produced, star-driven thriller; however, Nicolas Cage is no typical star, and this is no standard procedural. The actor has spent too much of the last decade slumming and sleepwalking through mindless paycheck pictures like Next, Ghost Rider, Bangkok Dangerous, and the soul-crushing National Treasure series, but every once in a while (I'm gonna say the last time was Lord of War) he gets his hand on a role with some power to it, and turns up the juice. This is the best work he's done in years, a deliriously unhinged performance that you can't take your eyes off of. He plays this guy from the outside in--the sheer physicality of the performance is impressive, not only in the expected addict's tics but in his peculiar walk (he uses an odd sideways lope, as if the gun in his belt is throwing him off balance) and strange speech patterns (as he becomes more addicted, he uses a chewed-up, stylized speaking voice that sounds like a contrivance but totally works within the context of the characterization). He indulges himself a bit, sure; he resorts to mugging in some of his close-ups, and the sheer theatricality of the performance may turn some viewers off. But it's a risky, impressive piece of work.

William M. Finkelstein's screenplay has some good scenes (including at least one that reminds of, and rivals, the shock value of that horrifying traffic stop in the original Bad Lieutenant) and a sound structure that allows for the indulgences of its director and star; it somehow seems perfectly logical that, midway through, McDonagh ends up heading to Biloxi with a fifteen-year-old witness and his dad's dog so that he can pick up his hooker girlfriend. The character is written with complexity beyond his vices; it is unfortunate but true that McDonagh is good at being a cop (even if he's not a "good cop"). He's got steady instincts, and he's strong in the interrogation room. If only he weren't having all those pesky hallucinations.

On the downside, Finkelstein's script occasionally dips into cliché dialogue and situations (we get stock scenes with Internal Affairs, and even that old standby scene where he's stripped of his gun) that the energy of Cage's performance and Herzog's direction can't quite transcend. The picture is also a tad overlong, and not all of Herzog's experiments work (I'm not sure what he's doing with the reptile-cam, but it doesn't play). But the screenplay provides a darkly comic motor to the picture, and much of it is played at that pitch, with great success--Cage's jittery explosion at a pharmacy clerk and his gun-waving interrogation of two elderly women build to juicy and explosively funny comic payoffs. It's got such a wicked and knowing sense of humor, in fact, that the mere phrase "property room" becomes a punchline by the picture's end.

While there are moments when Herzog revels in the swampy atmosphere, shooting with the anthropological instincts that he brings to his documentary work, he's mostly working on a broadly theatrical, almost operatic canvas, which is about the only way make a film that credibly contains Cage's gonzo performance. Frankly, a devlish sense of humor is about the only way to explain the closing scenes (with supporting characters making farce-timed entrances and exits to bring bits of news to our hero). It closes with what would seem the absolute antithesis of the downbeat yet inevitable ending of the original Bad Lieutenant, but its final scene finds a peculiar and perfect note, and holds it for as long as it can.

Jason lives in New York. He holds an MA in Cultural Reporting and Criticism from NYU.