Ken Ward has protested on railroad tracks to block coal trains, gone boating on the Willamette River to stop an icebreaking ship from reaching the Arctic and taken part in a covert operation to shut down an oil pipeline. Yet Lindsey Grayzel, whose documentary The Reluctant Radical chronicles Ward's emergence as one of America's most audacious and ferocious environmentalists, says Ward isn't defiant by nature.

"He had a lot of trepidation about breaking the law," Grayzel says. "He's an inherently conservative person. It was very difficult for him."

The Reluctant Radical will premiere as part of this year's Portland EcoFilm Festival, with Grayzel and Ward in attendance. Grayzel's work has often confronted tough topics. She's made several documentaries about families grieving after the suicide of a loved one. But making The Reluctant Radical was a particularly harrowing journey that placed her in the middle of Ward's one-man war against climate change. The result is a film that is both a vivid portrait of an activist and an addictive suspense thriller—a Hitchcockian riff on An Inconvenient Truth.

Confronting climate change hasn't always been at the top of Grayzel's to-do list. "I did what I could personally—have a little electric car, try and ride my bike and give a little money to Sierra Club or whatever—and then it was kind of out of my mind," she says.

Meeting Ward changed that.

The Reluctant Radical evolved as Grayzel was drawn deeper and deeper into Ward's world. She initially envisioned the film as a 10- or 15-minute short, but she was so fascinated by Ward that she set aside three projects to film him when he attempted to block a Shell Oil ship from leaving Portland in the summer of 2015.

Ward's activism was overshadowed that day by a group of Greenpeace activists who dangled from the St. Johns Bridge to stop the ship. But Grayzel continued to film Ward's breathtakingly brash acts of civil disobedience, including the time he dressed as Santa Claus and left a lump of coal in a stocking on a gas pump at an Exxon Mobil gas station. Eventually, Grayzel accrued enough footage for a feature film.

It was an undertaking that jeopardized Grayzel's career and future. On Oct. 11, 2016, she filmed Ward shutting off the emergency valve of the Trans Mountain pipeline, which delivers crude oil from Canada to the United States for refining. Both Ward and Grayzel were arrested. Grayzel faced multiple criminal charges, including burglary and sabotage, which were eventually dropped. Ward faced 30 years in prison (as WW reported in a cover story about Ward last year), but was sentenced to two days in prison and 30 days of community service when his trial ended in a hung jury.

Grayzel describes being arrested as an "absolutely terrifying" experience. But it didn't hamper her resolve—it hardened it.

"I felt like they knew that I was a filmmaker and that they were pressing charges to intimidate me and to intimidate future filmmakers so they wouldn't cover these stories," she says. "That made me more determined than ever to finish the film, and also, to know in my heart of hearts that, yeah, this story is important. It's definitely important to the pipeline companies. They are doing as much as they can to try and make sure that it doesn't get out there."

The Reluctant Radical unleashes waves of conflicted feelings. It takes you from the tension-soaked high of watching Ward snap a chain with bolt cutters to eerily intimate moments in which we see the emotional toll his grim quest exacts on his girlfriend, Laura Byerly, and his son, Eli.

Yet the film powerfully argues that an extinction-level threat demands an extreme level of commitment.

"The conversation with Ken made me realize how dire the situation actually is," Grayzel says. "We all have a stake in actually acting on this and not leaving it to the Sierra Club to try and figure it out, because frankly, no one's been doing a good enough job."

SEE IT: The Reluctant Radical with Lindsey Grayzel and Ken Ward is at the Hollywood Theatre, 4122 NE Sandy Blvd., hollywoodtheatre.org. 7:30 pm Saturday, April 21. $10.