Filmmaker Walter Dominguez’s odyssey to unearth elements of his ancestral history began, simply enough, with a black and white photograph of a man named Praxedis G. Guerrero.

The cast and crew of “Weaving the Past: Journey of Discovery” work on the documentary, which chronicles Walter Dominguez’s effort to understand his grandfather’s past. (photo courtesy of Walter Dominguez)

It belonged to Dominguez’s grandfather, an ordained Methodist minister who died in 1973, and would be the foundation for a journey that walked Dominguez through his grandfather’s upbringing, an era rife with corruption and bloodshed.

“It was just a horrific situation for millions of people,” he said of Mexico during the turn of the 20th Century.

Dominguez’s grandfather, Emilio N. Hernandez, had played a part in the Mexican Revolution, but to some relatives, he was known only as a benevolent clergyman who was one of the first pastors for La Plaza United Methodist Church in downtown Los Angeles.

That contrast is the basis for “Weaving the Past: Journey of Discovery”, a documentary by Dominguez and his wife, actress Shelley Morrison, who portrayed Rosario in the TV sitcom “Will & Grace”. The South Carthay residents will screen the film at the Linwood Dunn Theater in Hollywood at 7 p.m. on Saturday.

“It’s been an incredible journey. …The journey is the reward, and the reaction to the film has been extraordinary,” Dominguez said.

He said he began to research his grandfather’s history at the turn of the 21st Century. At the time, Dominguez had turned 50 years old, and a friend who was the same age had just died of a stroke. Further, 9/11 was still fresh in his mind, and his father was ill, fragile and losing strength, he said.

“There were a lot of things happening in and around that time that brought me to a crossroads,” Dominguez said. “And I really needed to tap into something … that would really propel me forward.”

In his effort to find solace, he opted to reconnect with early memories of his grandfather, who Dominguez described as an “incredibly positive” individual he had looked up to since childhood. He had affectionately referred to Hernandez as “Tata”.

“He just always believed that the day would bring something good, and it always did,” Dominguez added.

To uncover Hernandez’s past, Dominguez said he began a series of trips from the U.S. to Mexico to interview family members. He was considering the possibility of making a documentary about the excursions, but he said he also wanted to videotape the interviews so that he could show them to his ill father.

“Soon, it became clear [the research would translate into a good film], because fascinating things kept unfolding,” Dominguez said.

He had the support of Morrison, who could only take a few trips alongside her husband because of filming commitments for “Will & Grace”. She was also battling cancer, but, as she said, “I’m a tough, old broad.”

It was through his interview with his mother that Dominguez learned of the photo of Praxedis Guerrero. Initially, the family could not find it, so his mother said a prayer, Dominguez said. His father had been looking for the photo in a bedroom closet.

“It was literally in a shoebox that fell on his head,” Dominguez said.

Likely taken between 1885 and 1895, the photo was protected by a leather jacket. Dominguez said his grandfather had cherished the memento, a gift to him from Guerrero, his best friend growing up.

Dominguez said he learned that Hernandez had been born into poverty in a remote mining town in Mexico, and due to an abusive stepfather, ran away from home at age 5. It was Guerrero’s family who took the boy in, and he worked on the family’s hacienda for the next 10 years, the filmmaker said.

Guerrero would eventually become a writer and political radical who fought the policies of the Mexican president, Porfirio Diaz, a dictator who rose to his leadership post as a national leader and liberator, Dominguez said.

In 1904, Guerrero and Hernandez fled Mexico to escape retaliation for their outspoken opposition to Diaz, he said. Dominguez said they came to Los Angeles to disseminate news criticizing the regime for its harsh labor practices, which sometimes involved slave labor. In L.A., they organized a revolt.

“They had no choice but to leave Mexico,” he added.

Eventually, Hernandez fell into the hands of the Methodist church. After a bout with homelessness, he befriended a missionary who steered him toward spirituality and the church, Dominguez said.

“They saved his life, quite honestly,” he said, adding that his grandfather lived the next 50 years as a humble, sharing man of God.

Learning his grandfather’s story — and being able to tell it — has been therapeutic for Dominguez. He said the experience made him realize “you just have to go on with life, look at the positives and light a candle.”

“It renewed me, and gave me a reason to go,” Dominguez said.

He said the documentary is “very universal” and “reaches out to everybody.” Morrison said it nudges people to learn more about their own ancestry and strives to bring families together.

“We need a film to reconnect, and this has a story — this has history,” she said. “You laugh, you cry, you talk about it afterwards. It’s a way to connect them and inspire them to interview their elders.”

Through their research, Dominguez and Morrison also found a new effort to benefit. The couple has become familiar with La Plaza United Methodist Church, which had been in jeopardy when its lease was not renewed by the city, Dominguez said.

He said supporters attended Los Angeles City Council meetings and lobbied to have the lease renewed. One thing that helped the cause was the church’s plans to construct a museum in its basement, Dominguez said.

The city signed the lease four months ago, and work is currently underway to open the museum, the Los Angeles United Methodist Museum of Social Justice. Morrison and Dominguez, who sit on the museum board, will use the proceeds from Saturday’s screening to benefit the museum.

“It’s a great opportunity to provide something for the public to enjoy and learn about their own city,” Morrison said. Dominguez added, “Nobody else has this collection. Historians salivate when they see the images.”

The Linwood Dunn Theatre is located at 1313 Vine St. The event begins at 6 p.m., and tickets are $100. For information, visit www.weavingthepast.com or www.museumofsocialjustice.org.