Michael Morain | mmorain@dmreg.com

She had assumed the victims’ families wanted nothing to do with her. She was wrong.

When the San Francisco Opera commissioned a new show for the turn of the 21st century, they wanted something festive.

What they got instead starts with a double murder and ends with an execution. “Dead Man Walking” sets music to the true story of a Louisiana convict and the nun who befriended him on death row, a story made famous by her best-selling book and the 1995 movie starring Sean Penn and Susan Sarandon.

But the opera “is not about the death penalty. It’s about redemption,” said Kristine McIntyre, who is directing the production that Des Moines Metro Opera opens at the end of the month.

She called it a “spiritual journey” from vengeance and hatred to forgiveness and love.

McIntyre discussed the show during one of a half dozen events DMMO has arranged in the run-up to the work’s Iowa premiere. The series included an art show by Grand View University students, a roundtable with death-penalty experts, and a visit from the nun herself, who, in her own words, “didn’t know blue sky about opera” before this whole thing started.

Sister Helen Prejean didn’t know a lot of things, actually, and was quick to say so last month at Drake University’s Sheslow Auditorium. She’d been teaching inner-city kids in New Orleans in 1982 when someone asked her to write letters to a convicted murderer at the Angola State Prison.

“I was teaching eighth-grade boys English grammar. I mean, I love a challenge,” she said. “But I never dreamed of getting into something like this.”

She is a short, owlish woman with a folksy wit and a straightforward way of speaking her mind, sharpened now by two decades in the middle of one of the country’s most divisive debates.

She wasn’t always so outspoken. She grew up in a nice Catholic family in a nice big house in a nice neighborhood of Baton Rouge. Even after she joined the Sisters of Saint Joseph of Medaille, in 1957, she’d always thought that being Christian basically meant just being nice.

But that changed with the first letter she wrote to Patrick Sonnier, prisoner No. 95281, and the one he wrote back. (His name was changed in the movie and opera.) She started to visit him. She counseled him. She spoke up for him before the pardon board, while the parents of his teenage victims watched with seething disbelief.

Sister Helen was there, too, at his execution on April 5, 1984 — a moment the opera portrays with 90 seconds of silence.

“Music instructs and guides the emotions of the heart,” she told the Drake crowd. “And believe me: This opera is going to take you into every chasm of your heart that you didn’t even know you had.”

When the composer Jake Heggie asked Sister Helen for permission to write the new show, she agreed on two conditions. First, it had to focus on redemption. Second, it needed some decent tunes.

“I said, ‘Jake, we’re not going to have one of them modern atonal things that when you come out, you can’t even hum a tune,” she said. “And he said, ‘Sister Helen, you got it.’ ”

So Heggie set about the work of creation, writing music to the libretto by Terrence McNally (“Kiss of the Spider Woman,” “Ragtime,” “The Full Monty”).

Heggie had never written an opera before — he was working at the time in the San Francisco Opera’s marketing department — but the ideas came to him fast, with flashes of blues and rock and Cajun zydeco. He sketched one of the key scenes, at the pardon board hearing, in a single afternoon. It’s a sextet — a rarity in modern opera — in which the victims’ parents and the murderer’s mother pour out their emotions on the nun.

“You don’t know what it’s like,” one mother sings, “to see your baby grow up into a beautiful young woman, and then one night you see her walk out the door on a date and the last words you’ll ever say to her are ‘Fix your blouse.’ ‘Shut the door.’ And she’s gone.”

“You don’t know what it’s like,” echoes the convict’s mother, “to fail your child. Watch him slip from your hands and think he’ll never know how much I love him.”

Heggie said that’s the real heart of the show. “There’s this central idea about parents and children and love and loss,” he explained. “We’re all somebody’s child, and some of us are somebody’s parent … So each (character) is bringing something different to that moment, but they’re all connected by the same overriding emotions.”

He plunked out the melodic layers on a pair of tape recorders and played them for Sister Helen over the phone. The sound quality wasn’t great, but she was encouraging.

“It really captures the confrontation, the families’ anguish and pain,” she said. “That tension and anger and rage — it’s real. And I’m out of my depth, and all I can say is ‘I’m sorry. I’m sorry.’ ”

The Iowa legislature banned the death penalty in 1965, but there have been 1,379 executions elsewhere in the United States — mostly in the South — since the U.S. Supreme Court reinstituted the option in 1976.

A poll published this month by ABC News and the Washington Post found that 52 percent of Americans would prefer to sentence convicted murderers to life without parole, with 42 percent preferring the death penalty. That’s the first time the poll has ever found support for the death penalty slipping into the minority, down from its 80 percent peak in 1994. Renewed calls to abolish the practice rose again in April, after Oklahoma botched an execution by lethal injection.

Sister Helen can rattle off the statistics. She knows the legal arguments on both sides of the debate. She’s counseled more prisoners now and seen six of them die — and it all started with that letter.

“When you get involved in something bigger than yourself, it begins to summon gifts you never knew you had,” she said. “I didn’t know I could write a book. I didn’t know I’d be getting on a plane to talk to lawyers and judges around the world.”

But she’ll tell you: She is not the hero, not in real life or any of the fictional adaptations. She passes that honor to Lloyd LeBlanc, whose 17-year-old son was killed on a quiet night in the Louisiana woods in 1977. Patrick Sonnier and his brother, Eddie, had been rabbit hunting when they snuck up on the young man, raped his girlfriend and shot both of them three times in the back of the head.

At first, LeBlanc wanted to see the killers die. He was as outraged as everyone else. But after weeks and months passed, his anger didn’t subside. He was impatient. He snapped at people. He’d lost his old self until he realized, “Un-uh. They killed our son, but I’m not gonna let them kill me,” Sister Helen said.

In the small town where he lived, LeBlanc faced a lot of pressure to push for an execution. If he didn’t, he feared people would think he didn’t love his son.

So when he finally met Sister Helen at the pardon board hearing, he confronted her.

“He said, ‘Sister, where you been? I’ve had nobody to talk to,’ ” she recalled.

She had assumed the victims’ families wanted nothing to do with her, considering her support for the killers. But she was wrong.

LeBlanc “was the first victim’s family member who brought me into his heart and showed me a way out of vengeance and rage and onto a path of forgiveness,” she said.

“And that’s where the journey begins.”