NEW YORK (AP) _ Four decades ago in the Dominican Republic, three sisters stood up to a dictator who tried to cage their spirits. Their work in the underground resistance cost them their lives.

The story of the Mirabal sisters' murder on a remote mountain road by secret police haunted young Julia Alvarez, whose family had left the Dominican Republic for New York in 1960. Decades later, Alvarez wrote the novel ``In the Time of the Butterflies,'' based on the sisters' lives.

Published in 1994 and translated into eight languages, Alvarez's fictional account shared the Mirabal sisters' story with the world outside the Caribbean nation. Now, filming has begun in Mexico for a movie based on the book.

Starring Salma Hayek and Edward James Olmos, it airs next year on Showtime.

``It's really about being heroic and believing in freedom,'' said Helen Bartlett, one of the executive producers.

Alvarez, in a recent phone interview from her home in Middlebury, Vt., said she reviewed various screenplays before settling on this one. ``I feel like they've gone back closer to the novel and the characters I created,'' she said.

The book tells the stories of Minerva, Maria Teresa, Patria and Dede Mirabal, beginning with Dede, the one sister who chose a less confrontational path and survived.

As they grow from girls into women, the sisters find themselves clashing with the system then controlled by dictator Rafael Leonidas Trujillo. Alvarez writes that El Jefe, or The Boss as Dominicans called him, preyed on young women, and that in 1949 he had eyes for the strong-willed Minerva Mirabal. At a dance, Minerva found herself in his arms, and didn't want to be there.

``I push just a little against him so he'll loosen his hold, but he pulls me tighter towards him,'' Minerva says in the book. ``I feel my blood burning, my anger mounting.''

In the scene's climax, Minerva slaps Trujillo. Later, in what appears to be retribution, her father is arrested. The stage is set for a resistance movement led by the sisters, who become known as the Mariposas, or Butterflies.

In one passage, Patria Mirabal shouts ``Amen to the revolution!'' and describes the house where their movement was born. ``It was on this very Formica table where you could still see the egg stains from my family's breakfast that the bombs were made,'' she says.

In the movie, Minerva is played by Hayek, another of the executive producers. Olmos plays Trujillo, a figure who looms large in the memory of Dominicans. The actor transformed himself into the character by wearing a white suit and shaving his mustache and part of his head, according to Bartlett.

Salsa singer Marc Anthony also appears in the movie, which is directed by Spaniard Mariano Barroso and is being filmed in Mexico City and in Veracruz, on the Caribbean coast.

Alvarez, who teaches at Middlebury College, said she was invited to attend the filming, but declined. She and her husband, Bill, instead traveled this month to the Dominican Republic, where they have planted shade-grown organic coffee on their 260-acre farm in the mountains north of Jarabacoa.

Alvarez explains in a postscript to the book that her family fled the Dominican Republic in 1960 because her father had ``participated in an underground plot that was cracked by the SIM, Trujillo's famous secret police.''

In the same postscript, she writes that the book aims not at biography. ``What you will find here are the Mirabals of my creation, made up but, I hope, true to the spirit of the real Mirabals.''

Alvarez said by phone that as a child in the Dominican Republic, she never heard criticism of Trujillo. But she sensed something was wrong. One day, while watching a Western film on television at the home of a general who lived nearby, Alvarez said she saw a gun on the screen. The general asked: Had she seen one before? The girl said yes, her father had one.

The general asked what he planned to do with it.

``I had to think of the biggest thing he could do,'' Alvarez recalled. So she blurted out: ``He's going to kill Trujillo.''

The general never acted on what he must have assumed was the active imagination of a child. But for months, Alvarez says, her family lived in terror, and her mother ended up spiriting her father's gun out of the house and leaving it with a relative.

Trujillo was assassinated in 1961, and nearly four decades later, Alvarez said, she has heard her book is required reading in some Dominican schools.

Alvarez also said the surviving sister, Dede, reacted favorably to the book. Dede, who still lives in the Mirabals' hometown, Ojo de Agua, has made the family home into a museum in honor of her sisters.

The Mirabals continue to be an important name in the Dominican Republic. Dede's son, Jaime David Fernandez Mirabal, served as vice president under former President Leonel Fernandez.

Bartlett said that as chance would have it, filming of the movie is to be completed on Nov. 25 _ the 40th anniversary of the Mirabal sisters' deaths.

___

On the Net:

Mirabal museum: http://www.conectados.net/mirabal/museo.html

Showtime: http://www.sho.com.

___

Elsewhere in television ...

`20/20': Barbara Walters speaks with Heather Mills _ model and champion for the disabled _ about her turbulent childhood, the accident that caused her to lose her leg and her relationship with Paul McCartney on ABC's ''20/20'' Friday. Mills, 32, is the daughter of what she says was a violent and abusive father and, homeless at 14, she lived in London's Waterloo station. Within a few years, she was a highly paid model who used her modeling income to aid war refugees in the former Yugoslavia, many of them amputees. At 25, she became an amputee herself, losing her leg in a traffic accident. She continued her charitable work, which brought her together with Beatle legend McCartney. Today, the two travel together, working for an international ban on land mines. The interview airs at 10 p.m. EDT.