Bruce Wagner has led a quintessential Los Angeles life, and the city infuses both his novels and screenplays. "I grew up in Beverly Hills," he says, "so Los Angeles is the front yard and the backyard. It's the pool house, the living room, the garage. It's all of those places that I call home." Though his ambition had primarily been toward fiction writing (and to this day he considers himself a novelist first and screenwriter second), when he was driving a limousine at age 25 he had the opportunity to collaborate on a screenplay which Robert Stigwood would produce nine months later called Young Lust.

The satirical comedy in the vein of Young Doctors in Love was never released but the script was well regarded, and assignments ensued for Wagner. "That experience formed a template of failure and humiliation that has been a mother lode for me," he says. "Those were aspects of career not personal anguish that I drew from. But suddenly I was writing a few scripts a year for what I considered a lot of money. I'd slowly embarked on the road to corruption and hackdom. It was a novelty to be that young and having gone from driving a limousine to having some sort of a career, but the novelty wore off after a few years and left me deeply unsettled and conflicted about what I was doing."

Wagner wrote a series of short stories inspired by F. Scott Fitzgerald's Pat Hobby stories, about a failed alcoholic screenwriter, called Force Majeure: The Bud Wiggins Stories, which got him a book deal and a failed tango with Oliver Stone to adapt them to screen. "I had pretty much been true to my protagonist, the cowardly screenwriter; I had adapted a watered-down version of a book that was authentic and close to my heart."

In the film, Julianne Moore plays Havana Segrand the selfish, actress daughter of a classic Hollywood star, struggling for work and receiving therapy from celebrity therapist Dr. Stafford Weiss (John Cusack). Havana blames her late mother for molesting her as a child but is vying for the part to play her in a biopic, but loses out to another actress. She takes as an assistant Agatha Weiss (Mia Wasikowska), the schizophrenic daughter of Dr. Weiss who had been banished to a hospital in Florida after her delusions led her to burn down their house and almost kill her brother, years before. But Agatha returns seeking to make amends, particularly with her brother, Benjie (Evan Bird), a young star and nightmare brat of the first order. From here tragedy ensues as the past bubbles up for Havana and the Weiss family, sometimes in the form of hallucinations. Wagner had struggled with "a fair amount of addictions" and considered himself in decline when, in what he describes as "a real cri de c ur, a howl in the wilderness for me," he wrote the screenplay for Maps to the Stars, a dark tale about a corrupt and grossly dysfunctional Hollywood family and the equally corrupt people in its orbit. He put the script away for many years until he shared it with his friend David Cronenberg, who decided to take it on.

Maps to the Stars is not exactly a love poem to Los Angeles. Talk to me about L.A. as a location and even as a theme.

Bruce I went to school with children of celebrities, children who were celebrities, I lived next door to celebrities. My father was marginally in the business and I used to go to the drugstore at the Beverly Wilshire to pick up Variety for him, and I would see Groucho Marx. It's part of the fabric of that world that I grew up in. While all my books are not about Hollywood, it's a reflexive backdrop for much of my work. I have no interest to make a comment on the mores and manners of Hollywood whatsoever; of the industry of show business. Nothing could interest me less. David [Cronenberg] and I did not want to make a satire. Maps to the Stars is kind of a fever dream. It's an ethnographic or anthropological study of a dysfunctional family that live in a town that is a bright laboratory of human behavior. But I've written about human behavior in extremis all my life, the sacred and profane. Extreme fame, extreme anonymity if anonymity can be any more extreme than erasure extreme wealth and poverty, addiction and abstention. I tend to write about those poles. For David there was something about those themes, the way they were handled, and the mutilations presented of body, mind, and spirit that appealed to Cronenberg. Our DNA kind of co-mingled on this project.

I was going to ask how his voice augments yours.

That's precisely the way to put it. My voice is just a voice unless the embodiment is a film. So David was really the throat through which that voice poured, the physical features of the singer, David orchestrated that. His fingerprints are on every frame. Julianne Moore said that I brought a kind of superheated quality to the affair. I bring a messiness and operatic, telenovella aspect whereas David brings a coolness and formalism. The convergence of those two poles or extremes create this kind of chamber piece that we wound up with for Maps.

What do you find to be the greatest challenge in the writing? Pulling off a character's hallucinations can be hard.

I was writing the script as a catharsis. My tuning fork was every scene had to provide or propel me toward it. Sometimes the violation of taboos would be cathartic for me; to have a little boy say what he says in the beginning to his agent, "Show me your cunt, Jew faggot." To write something that was unimaginable to be filmed was cathartic. The image of a celebrity's assistant menstruating on her pure white, expensive couch, just a dot of blood what would come before that and after that that was enough to propel me toward being interested. It got my attention. As long as the characters and scenes got my attention, that was my emotional tuning fork. So to write in an extreme way but in a way that is an entertainment was what I wished to do with Maps.

All these characters are loathsome in some way or potentially so. What is required to keep them compelling enough that an audience still invests in them?

I was in the Hollywood trenches for a long time where the mantra was, "The character is not likable." To me that's a psychotic mantra, a fetishistic mantra and make sense on no level. If a character is compelling they are compelling. One could say Julianne Moore's character is grossly unlikable, but if you are compelled by her character and you love Julianne Moore's performance, you then will modify that and say, "You know, she was likable." It makes no sense to me, and I run from that kind of definition. Julianne's and Mia Wasikowska's characters were really the same character for me, just different sides. It was enormous fun writing Havana because she wore her desperation, fear, and shame on the outside. She had no skin and almost grounded herself by this daily cathecting, daily vomiting forth to the world of her fears. And what emotional scars she had from the incident where she claims her mother molested her, those scars are deep inside.

Mia's character wore her emotional scars externally, literal scars from a fire, and repressed everything. You would never know what she's thinking or feeling whereas with Julianne's, you always did. The irony is that as the script progresses, Julianne gains her self-confidence because she gets this role that she is coveting, which is her downfall. Mia throws her medication away and that's her downfall. But you have to have some joy and interest; you have to be thrilled as a writer, otherwise there's no point.

Tell me about John Cusack's character. You have had some experienced gurus yourself, Carlos Casteneda, for example, and that's the position this character takes. It's such a particular relationship and personality. Did that inform his character at all?

I didn't see Cusack as a guru. I see him as a celebrity psychotherapist.

Does he see himself as a guru?

He sees himself as a brand. This character is not based on Werner Ehrhardt, but est, Scientology, these were all the synthesis of so many modalities and California is a hotbed of that. I was raised in California, and there is a contagion; celebrity is a very strong virus and therapists are infected by it as well. If you are a therapist and have a famous patient versus a patient who is not as compelling, whose call will you take? So I see Cusack as an opportunist and a creature of the media. I certainly don't see him as a guru or having to do with any of the men that I have met, respected and had an association with.

You reference a string of real Hollywood names in the script and Carrie Fisher even has a cameo appearance. That's a choice, to bring that level of reality into your story rather than making up names. What does that give you?

It's a minor device that simply leaves in strands and fibers of the carpet which the characters are trodding on. Creating names would be absurd. I don't do that in my fiction. To me, the movie's context is reality. To me it's not a Fantasia, the supernatural elements of the ghosts notwithstanding. David shot this as hyper-realism because otherwise it could have been camp if the actors and the director had had a different notion. You can make anything high camp. For me I drew more on my love of Strindberg and Joe Orton than anything else. For example, Michael Douglas was an actual character in my book "Dead Stars." But the idea of creating someone that resembles Michael Douglas didn't occur to me.

Suicide plays a redemptive role in the film. It's not an uncommon device but I wondered how it works or what meaning it had for you.

I'll just say that incest is a theme in the film; Agatha is doomed in a sense and wishes to escape the horrors that have been perpetrated by her parents, but can't fully. She can't shatter the incestuous template. She does have an incestuous relationship with her brother but it's non-erotic. It's tender, not physical. Yet she is still compelled to have the marriage ceremony in the film. Her liberation is through suicide. I hope that we feel some compassion for Agatha and see that this is an acceptable way out of the dead end, moral and even physical problem. Of course it's presented in a way that for me is lyrical and dreamlike, but I avoid any kind of moralizing in the film; whether a character's actions are appropriate or not is not my area of jurisdiction.

You seem to have had a close involvement with the film's making.

I was very lucky in that David is the final arbiter, and we had no interference whatsoever. It was a very unusual situation. I was on set every day so in that sense it felt very collaborative although I had no desire to question David's choices. I was completely in his hands and trusted him implicitly. But the idea that the writer can craft a script and have it be faithfully followed, to the point where David would make the decision whether to do another take or not, if an actor left out an "and" or "the"; that the most taboo things that I'd written the celebratory dance after Julianne's character learns that a competitor's child has died, the toilet scene, the menstruation scene, or the little girl appearing as a ghost with tattoos on her body in a wedding gown that this would be faithfully replicated, interpreted and explored by another human being, shattering this idea of the writer as an isolated figure who has been abused by the director, where I could really step into the same pod with David as in The Fly, and literally become conjoined, that was thrilling to me and very unusual. I doubt that will happen again. I'd say that was the most extraordinary thing. It was like writing a piece of music and then finally hearing it after so many years.