2 men, 1 obsession: the quest for justice

Other serial killers were caught, but not Zodiac -- which as a kid Fincher resented. "When you finally saw David Berkowitz ("Son of Sam"), you got to erase it, because you were, 'Look at you. You are a schlub.' What is the line the Good Witch says in 'Wizard of Oz'? 'Oh, rubbish, you have no power here. Leave before somebody drops a house on you.' "

Fincher remembers when his family left the Bay Area when he was 8. As he watched the hills recede from the back of his family's Audi, he said, he thought about the Zodiac killer and wondered: Are they going to catch that guy?

"It didn't keep me up at nights, but it was one of those things on Halloween when you are 8 or 9 years old and you curb your egging of houses and toilet-papering and go home at 11 because the Zodiac is out there," he says.

"Artists always harken back to that, which aroused the moral and erotic imagination," says Ellroy. "With me it's my mother in conjunction with 'The Black Dahlia.' Sex, justice, morality, the details of police work and forensic detection, lives in enormous duress -- that's what gets us inchoate. Years later we become dramatists. We want to get back. We want to know how we got to where we are today. We want to honor the gift that we were given imaginatively."

Fincher and Ellroy know each other slightly, because at one point Fincher was going to direct the screen adaptation of Ellroy's "Dahlia" book. He wanted to make a five-hour, $80-million miniseries with movie stars -- and when that fell through, he turned to Zodiac, which dealt with similar themes. They met up recently at Fincher's Modernist Hollywood office -- Ellroy came along primarily because he is such a fan of Fincher's movie, which lands in theaters Friday. The conversation turns and returns to what binds the two -- a mutual interest in obsession and the destruction it leaves behind. Still, given the nature of their temperaments, the author offers a distinctly more visceral take and the director a more analytical one.

For Ellroy, who has grown to hate the helter-skelter pace of so many testosterone movies, the film vividly re-creates what he experienced when he teamed with retired Sheriff's Deputy Bill Stoner to reinvestigate his mother's death. "It was read files, talk, engage in interviews that went nowhere. The entire year fueled by what is the great dramatic tension of this motion picture; which was two hours and 38 minutes long; it is almost entirely conversation, discussion, rediscussion, reassertion, and it's a wholly tense, kinetic filmgoing experience. I've never seen a film that so gloriously and intelligently captures their lives and what homicide work is."