Sarah Michelle Gellar

A staggering, epic-length, soon-to-be-legendary mess, Richard Kelly’s "Southland Tales" takes place in Los Angeles a few years after a terrorist nuclear attack on the U.S. There we meet a cast of characters so vast and befuddling that any attempt to describe them all will simply give you a headache.

Suffice it to say that the movie stars Dwayne "The Rock" Johnson as an amnesiac actor; Justin Timberlake as a scarred Iraq war veteran; and Sarah Michelle Gellar as a porn star turned talk-show host. Suffice it to say, also, that none of the actors seem to have any idea what this movie is about or what point Kelly is trying to make.

The plot, if that’s what you’d call it, seems to have something to do with a powerful alternative fuel source that a number of people are competing to claim as their own. But, really, "Southland Tales" doesn’t tell a story. Instead, it presents a series of bizarre, disjointed scenes in which the tone veers wildly from "Saturday Night Live"-style spoofery (watch out for "SNL" alums Cheri Oteri and Nora Dunn in supporting parts) to What the Bleep?-style mysticism (Seann William Scott plays a police officer who, if he meets his long lost twin, will cause the time-space continuum to collapse — or something like that).

After about 30 minutes, it’s clear that Kelly — who made a promising debut a few years ago with the time-travel fantasy "Donnie Darko" — is hopelessly in love with every one of his annoying, fanboy-ish ideas.

And yet, as often unwatchable as "Southland Tales" is, the writer-director deserves some points for ambition. With its swirl of cinematic references (chiefly to Robert Altman’s "Nashville" and David Lynch’s "Mulholland Drive") and its cautionary tale of a consumerist society run amok, the movie has a certain stream-of-consciousness flair.

And for at least one five-minute sequence, an out-of-left-field musical number in which Timberlake lip-syncs the Killers’ "All These Things That I’ve Done" in a bowling alley (as a group of Marilyn Monroe impersonators dance behind him), it’s flat-out dazzling.