The film begins with an attempted murder on a pitch-black night on LA's Mulholland Drive that turns fatal when a carload of partying teenagers hits their limo. The targeted victim, a luscious brunette beauty (Laura Elena Haring), is the sole survivor, and she stumbles away from the wreckage seeking shelter in a gorgeous nearby apartment that has been left empty by a vacationing actress. She is discovered the following morning while taking a shower by the chipper Betty (Naomi Watts), an Ontario native who has come to stay at her aunt's place in Hollywood as she attempts to start an acting career. The woman, who has no memory, tells Betty that he name is Rita after seeing a poster for "Gilda," starring Rita Hayworth. Betty and Rita become self-appointed detectives, as they decide to find out who Rita is and what happened on Mulholland Drive.

In an interweaving storyline, a young, hotshot director named Adam Kesher (Justin Theroux) is preparing to cast his latest picture. Although several big name actresses are knocking on his door for the part, mysterious forces begin inundating pressure on him to cast a new ingenue named Camille, or pay the possibly deadly consequences.

This is the basic setup of "Mulholland Drive," although to give anything else away is to, conflictingly, steal the pleasures of discovering the film as it plays out, and to not give much away at all. Suffice to say, roughly 105 minutes into the movie, something both shocking and bewildering occurs that stands everything that has come before on its head. Characters suddenly take the identities and personalities of other characters, scene after scene abruptly cuts off before it conventionally concludes, and the whole world becomes an alternate reality where you're left unsure if any of the movie has been real, or just a frightening, disorienting dream.

"Mulholland Drive" has been highly publicized to have originally started off as a TV pilot that was rejected by the network. Foreign financier Studio Canal offered Lynch $7-million to reshoot and further develop the story into a complete feature film. Doing such a thing could have proved horribly uneven, but the halves blend so seamlessly into a whole that you would never be able to guess the history of the project without already hearing about it.

An almost epic-sized picture with a huge cast of lead characters, supporting ones, and memorable cameos, the movie offers scenes in the first half that seem potentially unnecessary, as if Lynch has decided to just shoot material that is freakily "out-there," but everything masterfully and satisfyingly reemerges in the later sections, leaving you giddy to see what the master filmmaker has up his sleeve next. One such sequence, in which a nervous man tells his friend about a horrifying nightmare he had the night before about the diner they're eating in, only to minutes later see his fears come true in reality, leads later on to a small, eerie blue box that is found by Betty and Rita. What powers the blue box holds is best left undisclosed, but it paves the way for the disturbing final 40 minutes.

As protagonists Betty and Rita, Naomi Watts (1998's "Dangerous Beauty") and Laura Elena Harring (2000's "Little Nicky") are brilliant, giving multi-layered performances that compliment the off-kilter, intricate plot. Watts is, at once, innocent and bright-eyed, but has an obscure, sexual side that is discovered as the film progresses and her intentions change. Harring is just as boldly good, making Rita into a person both scared out of her wits and curious of her forgotten, concussion-induced past.

Justin Theroux (2000's "American Psycho") is appropriately high-strung and self-absorbed as rising filmmaker Adam Kesher, who suspects his life may hang in the balance of who he decides to cast in his new movie, after a strange meeting he has with a stranger named The Cowboy (Monty Montgomery).

James Karen (1999's "Any Given Sunday"), as a studio casting director; Lori Heuring (2000's "The In Crowd"), as Adam's cheating wife; country music singer Billy Ray Cyrus, as the man she is having an affair with; Monty Montgomery, as The Cowboy; Robert Forster (2000's "Me, Myself & Irene"), as Det. Harry McKnight; Dan Hedaya (2000's "The Crew"), as a peculiar studio exec; Missy Crider (1995's "Powder"), as a waitress whose name inexplicably changes from Diane to Betty; and Melissa George (2001's "Sugar & Spice"), as debut actress Camille Rhodes, round out the fine supporting cast. Finally, Rebekah Del Rio performs Ray Orbison's "Cryin'" in a nightclub completely in Spanish, and it is such an overwhelmingly powerful rendition that she leaves onlookers Betty and Rita in tears.

Mix in an elderly couple who have demented smiles plastered on their faces at all times; a rotting corpse in a motel room whose identity isn't fully discovered until the end; a wheelchair-bound midget (Michael J. Anderson) in a glass room that listens in on the conversations of movie studio bosses; and a psychic who comes to Betty's door speaking of horrible things she senses are coming to either her or Rita, and you have only just scratched the surface of the alternately inventive, confusing, thought-provoking world that David Lynch has created here. With a superb, offbeat music score by Lynch regular Angelo Badalamenti, "Mulholland Drive" is a masterpiece. What it all means is up to the viewer to decide, and if your movie tastes can handle an unconventional, direct assault of the senses and mind, you'll have an absolutely great time trying to piece everything together. I know I did, and I'm still thinking about it.