It's no secret that Nicolas Cage has been going off the deep end of late. His performances have become increasingly unhinged and harebrained; you never know when the character he's playing will suddenly become apoplectic over something that seems -- no matter what it is, in comparison to the reaction it draws -- relatively minor. This almost singlehandedly ruined this year's Knowing, at heart a decent science-fiction flick rendered nearly unwatchable by Cage's fevered overacting. It's no coincidence that Cage hasn't done a "serious" dramatic performance in more than three years. I shudder to think what that would now look like.

All of which makes me think that Werner Herzog is even smarter than people give him credit for. Having cast Cage in his "remake" of Abel Ferrara's Bad Lieutenant (I put "remake" in scare quotes as Herzog claims to never have seen Ferrara's film, and the new one has nothing to do with it beyond sharing some bare plot elements), he lets the actor go truly all-out. In The Bad Lieutenant: Port of Call New Orleans, Cage, playing the titular Lieutenant Terence McDonagh, interrupts himself, has roundtable discussions with himself, cheers himself on, punctuates conversations with non sequitur chuckles and handclaps, and gets hugely angry. It's a completely absurd performance -- and, God willing, a way for the actor to let off steam and return to the more nuanced, settled acting he used to do.

The movie itself is a hilarious genre pastiche that too frequently winks to let us know how aware it is of its own unseriousness. Herzog is having every bit as much fun as Cage here, toying with renegade cop movie cliches and working in a pulpy mode he hasn't touched for a while. In terms of individual scenes, The Bad Lieutenant has several of the year's highlights, including a tour de force in which Lieutenant McDonagh stops a pair of youngsters on their way home from a club, confiscates their drugs, snorts them, and has sex with the girl while forcing the guy to watch. (You have to imagine this performed in a full-on Nic Cage-ean fury for the full effect.) He's one bad Lieutenant indeed, though the movie makes clear that he has an honest streak: he'll pocket all the dope he can, but -- unlike his partner, played by Val Kilmer -- he stops short at, say, murdering a drug dealer in "self-defense" to pocket his money.

The Bad Lieutenant works great as an over-the-top cop thriller with a bonkers lead performance. Certain scenes brilliantly straddle the line between weirdness and madness, as when Cage emerges from behind a door to harass a grandmother while brandishing an electric shaver. (Look for this scene -- it's incredibly bizarre, but it makes sense somehow.) Other times, however, Herzog loses sight of this delicate balancing act and does something to break the spell. When Shea Whigham shows up in a quirky cameo as a local rich hotshot whose m.o. is to repeat "whoa" as much as possible, also throwing in an occasional "oh yeah," it feels like not only is Whigham mugging absurdly for the camera, but Herzog is, too. And when Herzog busts out some of his characteristically surreal touches -- e.g. having the drug-addled protagonist stare at an iguana for a good minute and a half -- the movie starts to seem less like a fun genre experiment and more like arthouse wankery.

That Herzog chose to set this film in hurricane-ravaged New Orleans is probably not coincidental, and the subtext here seems to be that it's possible to find goodness and forms of heroism even when things get really -- really -- f'ed up. Parts of The Bad Lieutenant are rather paradoxically touching: we sense that McDonagh really does mean well, but how can that be given how much of a prick he clearly is? Eventually things start going well for the Lieutenant, in a series of scenes both hysterically funny and oddly rewarding.

If you're a fan of this genre, this could be your chance to watch a smart filmmaker take it in some strange and interesting directions; if you're not, this is your chance to watch a smart filmmaker make fun of it. If you've been following Nic Cage's increasingly intense scenery-chewing over the last couple years, this is your chance to see it taken to its logical conclusion and beyond. Herzog occasionally makes The Bad Lieutenant feel frivolous, but it's rarely less than fascinating.