MONHEGAN — Politics, lobstering and love drive the story being filmed on the island this fall.

“Catatonk Blues” is an independent production of a script written by Bob Mrazek, a summer resident since 1984, and directed by Mrazek and Jared Martin, also a long-time summer resident.

The film features actors Treat Williams (“Hair,” “Once Upon a Time in America” and the TV series “Heartland” and “Everwood”), Elizabeth Marvel (“Hyde Park on the Hudson,” “True Grit” and “The Bourne Legacy”), George Hamilton (numerous TV series, movies and feature films), Ryan Merriman (“42,” the recent film about Jackie Robinson) and Marshall Bell (“Total Recall” and “Twins”).

Another island summer resident, Josh Mostel (son of Zero Mostel), who acted in “Billy Madison” and “City Slickers,” also has a small part in the film.

Actors are working for the minimum “scale” pay, Mrazek said in a telephone interview, a testament to their belief in the story.

Catatonk is the fictionalized name for Monhegan. The story follows a representative to Congress who returns to an island in his district in Maine as he nears retirement. Conflicts between island and mainland lobstermen and other matters create dramatic tension.

“It kind of wrote itself,” Mrazek said of the screenplay. “I wanted to write something that reflected the place the island has had in my life and in my family’s life.”

The story’s themes are “an island fighting to save itself from commercialization and freedom of expression,” he said.

Mrazek was a five-term Democratic Congressman from a wealthy, heavily Republican district on the north shore of Long Island, N.Y., he said, serving from 1983 to 1993.

“I think I did some good work,” he said of those years. As a young man, he was attending the London Film School in 1968 when Robert Kennedy was assassinated which diverted his career path to politics. This film is a return to a first love, he said.

“After I left Congress, I decided I wanted to write,” he said, and to date, he has completed seven books of fiction and non-fiction.

Mrazek showed the Catatonk screenplay to a friend, Fred Roos, who produced films by Francis Ford Coppola, including “Godfather III” and “Apocalypse Now.” Roos was impressed with the story and encouraged and helped him produce it; by filming two-thirds of the story on the island, the small budget could be stretched, he told Mrazek.

A town meeting scene will be shot in Rockland at the former high school on Lincoln Street “with a ton of extras,” and Mrazek even got permission to shoot some scenes at the State House in Augusta in October.

“I was aiming for a Capra-esque scene,” he said, with the Treat Williams character playing “a Jimmy Stewart role” as he fights for his reputation.

“It’s a film with serious aspirations,” Mrazek said. It is expected to be completed in the spring.