out of four stars

Rating: R.

“Inherent Vice” is an absurdist gag from the occasionally brilliant writer/director Paul Thomas Anderson, whose exquisite filmography runs from “Boogie Nights” to “There Will Be Blood.” It’s based on a crime comedy by acclaimed novelist Thomas Pynchon and filmed with a superb cast, including Joaquin Phoenix, Josh Brolin, Reese Witherspoon, Benicio Del Toro and Martin Short.

Its premise — a mystery investigation by Doc Sportello (Phoenix), a flaky doper gumshoe who could get tangled tying his shoes — is a nice departure from dull corporate franchise films, a hippie-noir cousin of the Coen brothers’ beloved “The Big Lebowski” and Robert Altman’s classic detective parody “The Long Goodbye.”

I truly wanted to like the film. Unfortunately it is a huge letdown, an almost unbroken and utterly unsuccessful sequence of wrong choices. I’ve seen more entertaining programming on the Weather Channel. Anderson lovers, Pynchon devotees and viewers who visit the theater at random will be equally dissatisfied. The joke’s on us.

The story, set in 1970 Los Angeles as free love drifts away and paranoia creeps in, begins with a request for help from Sportello’s ex. Shasta Fay (Katherine Waterston) has lost her new guy, a still-married construction magnate. His wife (and her boyfriend) had him committed to an asylum so they could hijack his fortune. They want Shasta to help them have him declared mad. This is believable, since he is officially Jewish but wants to be a neo-Nazi. Still, Shasta asks Sportello to defend her lover.

Sportello takes the twisted case, drifting into a convoluted chain of criminal undertakings and multiple doobies. Phoenix plays the low-rent investigator with a baked buffoon’s uncertainty. It’s clear he never knows whom to believe, though he tries to be groovy about most everything.

Should Sportello trust LAPD detective Bigfoot Bjornsen (Brolin)? He’s all snarling right-wing contempt unless he’s soothed by iced chocolate bananas or TV cameo roles on “Adam-12.” Is he a cop or a cop-out? What about Jade (Hong Chau), a Valley girl who operates a desert massage parlor popular with Aryan Brotherhood bikers?

Anderson’s film looks on with amused detachment as the laid-back Sportello deals with the hallucinogenic cast of characters. Whoever he follows seems to leave him with a nasty lump on his head. You’re laughing with the lead less often than you’re laughing at him, although in a 150-minute shaggy dog yarn you’re not laughing nearly enough. Brolin, Chau and especially Short are uproarious. Phoenix has some screwy touches — his muttonchops are comedy gold — but too often he’s trapped in wild-goose-chase conversations light on meaning and laughs.

The star of “Inherent Vice” is the helter-skelter screenplay, a self-sustaining ecosystem of frustrations in which each of a dozen characters — detectives, lawyers, wives, moguls, dentists and happy hippie hookers — wrestle with a set of desires that thwart the needs of someone further down the chain. The cosmic joke is that all think they’re on the pathway to vital discoveries.

The title seems to refer to a factor in the mystery of human life itself. Actually, the movie tells us, it’s a dry phrase from the insurance policy subdivision of maritime law, insisting that you can’t cover fragile cargo, since it breaks all the time. Much like the karma flotsam we meet through the currents of daily life — love affairs, acid trips, politics and indulgent movies.