A NOVEL TWIST

ZACH HELM says the epiphany that led to “Stranger Than Fiction” came to him while riding in his car: A guy hears a voice that, he realizes, is narrating his life. So he called producer Lindsay Doran to share his brainstorm.

“She said, ‘That is really funny,’ ” he recalls. “It’s not necessarily a movie, though.”

It took him two more weeks to come up with the needed complication: The unseen narrator would tell the man he’s going to die.

Doran produced 1995’s “Sense and Sensibility” and is close to that film’s star and Oscar-winning screenwriter, Emma Thompson. Helm from the start envisioned Thompson in his movie as the novelist narrating as she types out the story of this lonely man -- an obsessive IRS auditor -- except, she just can’t decide how to kill him off. The first scene he wrote, Helm says, had the poor fellow -- upon realizing he’s a character in someone’s fiction -- consulting a literary scholar, played by Dustin Hoffman, who asks him 23 questions to determine what sort of story he might be in. The professor delivers some reassuring news, “I’ve just determined conclusively that you’re not ... a golem.”

When Helm comes up with a line that strikes him as deliciously absurd, like that one, he has a way of rewarding himself. “I have this rule where if I have written this line or this scene that I consider to be particularly funny, or strong, I quit for the day. I just say, ‘That’s it. I’m done.’ ”

He is 31 and from Pike, Calif., in the Sierra Nevada, where his father was principal at a school with 69 students and his mother taught English while running the family raspberry farm. They would trek to a country store, Helm recalls, whose owner would sell fishing licenses or a cord of wood and suggest movies to rent -- the likes of Spike Lee’s “Do the Right Thing” and David Lynch’s “Blue Velvet.”

THE kid from nowhere studied drama at DePaul University in Chicago and wrote a couple of plays. “Stranger Than Fiction,” which opened earlier this month, is his first produced script. It might have been daunting to work with one of film’s Renaissance women, who by age 10, Thompson says, was imagining “long fairy stories [about] princesses who were made ugly because they were badly behaved” and went on to character sketches and then features, including epic costume dramas and last year’s children’s tale, “Nanny McPhee.”

But the 47-year-old Thompson says the deal with “Stranger Than Fiction” was that she’d be freed from worrying about the words -- “just come and act.”

She did speak up, though, when they shot a critical scene in which the sad-sack hero, played by Will Ferrell, first describes this voice running his life. Her thought was, “Is this going on too long?”

Helm cut away without complaint. Though a relative novice, he knew how you could fall in love with your words, and they still have to go. “You have to be Medea,” he says. “Yeah, you have to kill your children.”

The two of them were talking craft at The Times’ invitation, Helm in New York for a screening, Thompson by speaker phone from London. She mostly gushed over how he’d given her character “a huge movement of the soul” but did share a pointer or two, such as “what [producer] Jim Sheridan told me, that with a screenplay there has to be a huge magnet at the end. The influence is felt at the beginning ... and stronger and stronger as the film speeds up toward the final conclusion.”

Helm says he knew his ending early on: how Ferrell’s character would react to the realization that his life worked better, as fiction, if he was killed, and how Thompson’s writer would choose between what’s better for her art or for the life of this man.

Of course, an honest writer acknowledges that any story, however clever, is not 100% original -- witness all the films in recent years that have characters trapped in movies or video games. Helm cites influences such as Woody Allen’s “The Purple Rose of Cairo,” in which a celluloid star steps off the screen to romance a waitress, and “Six Characters in Search of an Author,” Luigi Pirandello’s 1921 play about a writer confronted by his creations.

“I’d go way, way back into Greek myth,” Thompson says. “ ‘The Odyssey,’ ‘The Iliad,’ the ways in which gods told stories that then had to be acted out. It’s about fulfilling the prophecy ... This is Oedipus, isn’t it?”

“With less sex,” Helm quips.

And you can talk about Greek tragedy in the same breath as your new comedy all you want and then a friend’s kid sees it and the 11-year-old’s favorite character is ... Will Ferrell’s expressive, mind-of-its own wristwatch. “Amazing!” Thompson says of the child’s-eye view.

Another thing about the writing game is how you can weave stories around a single character trait, as with the black bands tattooed around Helm’s wrists.

Helm, who has already made the vaunted leap to full auteur -- he’s in post-production on his directorial debut, a feel-good comedy, “Mr. Magorium’s Wonder Emporium” -- says someone suggested “I was trying to separate myself from, you know, part of me,” the work part, his hands. Then again, it could simply be “the old punk rock black cuff thing,” he says.

But Thompson offers a more intriguing scenario. “They’re covering something up,” she says of the up-and-coming writer’s tattoos. “It’s definitely something like, I don’t know, ‘Brigitte.’ ”

paul.lieberman@latimes.com.