In 2010, Island-raised filmmaker Victoria Campbell travelled to Haiti after the 7.0 magnitude earthquake devastated parts of the country. She was looking to gather footage for a documentary that would become her MFA thesis at the School of Visual Arts in New York. But she wasn’t looking to create a disaster aftermath story. Instead, she had her sights set on exploring the practices and traditions of Haitian Voodoo.

Shortly after arriving in Haiti, Ms. Campbell began volunteering at a hospital in Port-au-Prince. A few days into her work, she met a man named Gaston, who would change the course of her film, though she didn’t know it at the time. Though Gaston was a Voodoo priest, he was also a local community leader. He drove up to the hospital on his motorcycle to gather a group of doctors and nurses to take back to his neighborhood, which hadn’t received attention for 10 days because it was blocked off by masses of rubble. Ms. Campbell went with him and he showed her the ruins of his town and the people affected by it.

Monsieur Le President. — Courtesy Victoria Campbell

When Ms. Campbell returned to New York, she kept thinking about what she had seen. She remained deeply invested in post-earthquake Haiti, and Gaston’s neighborhood in particular. When she learned that Gaston had founded a community clinic called Haitian Solidarity to offer medical assistance to those in need, she packed her bag, grabbed her camera, and with $1,000 in aid from family and friends for the new clinic, flew back to Haiti.

As time passed and Ms. Campbell continued to travel between Haiti and New York, she witnessed Gaston undergoing a sudden and massive character shift. The man who had once given everything to his people mysteriously left one day, fleeing to Canada and pocketing close to $25,000 in foreign aid. Ms. Campbell decided that this man, whom she had considered one of her closest and most trusted Haitian friends, was the real protagonist of her film. Life had unfolded in front of her in a way she could not have anticipated, and this was the story she needed to tell.

But the subject switch did not occur without difficulty. To fill in Gaston’s backstory, which she hadn’t previously captured on camera, Ms. Campbell had to move in front of the camera to record conversations with Gaston. These scenes of confrontation and conversation are some of the film’s most crucial, for the film became not only about Gaston’s transformation, but how Ms. Campbell was also transformed through knowing him.

Gaston’s escape to Canada turned out to be short-lived. When he returned home, much of his life resumed as if uninterrupted, though also scarred by his betrayal.

In the editing room, Ms. Campbell worked to compile three years worth of footage into a cohesive story with a running time of 72 minutes. The documentary, titled Monsieur Le President, premiered in September 2013. Since then, some Haitians have seen it, and many think Ms. Campbell’s portrayal of Gaston is too forgiving, she said.

On Tuesday, August 12, Monsieur Le President will be screened at the Martha’s Vineyard Film Center in Vineyard Haven at 7:30 p.m. Ms. Campbell will hold a Q&A after the screening. She is hoping to raise money to travel to Haiti again to film Gaston watching the documentary, footage which she will potentially add to the film to round out its narrative arc.

Tickets are $15 for general admission and $12 for members. They can be purchased at the door or at mvfilmsociety.com.