LOS ANGELES (AP) — It wasn't a juicy script that brought together a half-dozen Hollywood stars, including Meg Ryan, America Ferrera and Olivia Wilde. It was the chance to tell the stories of women seeking, and finding, lives unbound by oppression.

"Half the Sky," a moving PBS documentary series airing Monday and Tuesday (9-11 p.m. EDT; check local listings), provides unflinching accounts of the worldwide exploitation and abuse that can ensnare women as well as girls. But it doesn't stop short of hopefulness.

The series details efforts to help females escape brutality and poverty through health care, education and economic advancement, sometimes fostered by those who themselves once suffered.

The extraordinary women featured in "Half the Sky" include Somaly Mam, who was forced into the sex trafficking trade as a youngster in Cambodia and now, as an adult, has created a program to help rescue girls from the life she once endured.

Mam and others like her "underscore that this isn't just an issue of really depressing things happening around the world because, side-by-side with the worst of humanity, you encounter the very best," said Nicholas D. Kristof, whose bestselling 2009 book (co-written with his wife, Sheryl WuDunn), inspired the PBS series.

That's what Ryan, who visited Cambodia for the documentary, found in one brave child.

"This little girl had been kept in a barrel and let out to service a man, put back, let out again, and that's her life. She said, 'People say love is hard. I don't think so at all. I think hate is hard. Love is easy,'" the actress recounted.

Ferrera read the book by Kristof, a New York Times columnist, and WuDunn before she was approached for the PBS documentary. She found their work — which includes a "What You Can Do" chapter to encourage reader involvement — a testament to women's refusal to be victims.

"All around the world, women are the ones pulling themselves out of these situations. When I read 'Half the Sky,' I would go from complete and utter rage to just smiling ear to ear," said the former "Ugly Betty" star.

A woman "can be at the bottom of the bottom and find a way not to just lift herself up but her family and her entire community," Ferrera said. "That made me really proud to be a woman."

Ferrera, Ryan, Diane Lane, Eva Mendes and Gabrielle Union took turns accompanying Kristof as he traveled to Asia and Africa to spotlight work being done to change the status of those who "hold up half the sky," as a Chinese proverb says of women.

Ryan said she and her fellow actors aren't claiming expertise.

As a celebrity, "you can just saddle up next to something smart and important and that will get some attention. And it's not like any of us are ... any more clear about it than anybody else," she said.

The documentary includes investigations of child prostitution in India, sexual assaults in Sierra Leone and maternal mortality in Somaliland where, according to the documentary, one in 12 women dies in childbirth because of malnutrition and the effects of genital mutilation.

These and other examples of abuse and neglect add up to an urgent global imperative, WuDunn said.

"In the same way that slavery was a moral challenge for the 19th century and totalitarianism was a challenge for the 20th century, the challenge that women and girls face around the world is the moral challenge of our time," she said.

At a news conference, Kristof responded to a question about whether America was imposing its beliefs on other countries.

"There are values that are oppressive to women that are embedded in a culture, sometimes in a religion, and I don't think one can ignore that fact," he said. "And it's also true that sometimes one can go in and end up causing more harm than good in the process of trying to bring about change."

"What we've tried to do is focus on organizations that are on the ground," at the grass-roots level, and try to "amplify their voices," he said.

"Half the Sky: Turning Oppression into Opportunity for Women Worldwide," introduced by George Clooney and airing as part of public TV's "Independent Lens" series, includes companion websites, social media campaigns supporting non-governmental organizations, and educational components.

The project, directed by Maro Chermayeff, is part of an initiative on female leadership from documentary producer Independent Television Service, PBS and the Corporation for Public Broadcasting, which funds ITVS.

LYNN ELBER, AP Television Writer