Director Leslie Zemeckis tells the strange story of Daisy and Violet Hilton in the luridly titled documentary “Bound By Flesh.” Conjoined twins the Hilton Sisters, stars of vaudeville, occasional movies and carnival midways, were a huge attraction in the early 20th century.

In “Bound By Flesh,” Zemeckis — the filmmaker wife of director, producer and screenwriter Robert Zemeckis — blends intriguing photos and film of the Hilton Sisters with commentary from experts and those who knew or encountered them. The documentary gives quite the full picture of the women, from their British birth in 1908 to their deaths in 1969 in Charlotte, North Carolina.

Images of the Hiltons being apparently rare, Zemeckis recycles some film and photos through the course of her 91-minute film. Some footage, being so extraordinary, is worth an encore. There’s a short silent clip of the smiling Hiltons in their teens, for instance, as they walk, unavoidably together, on a city sidewalk. They were indeed bound by flesh.

In addition to being born joined by “a ribbon of flesh,” the girls suffered the misfortune of being born to an unwed mother who was horrified by the sight of them. In the hours after their birth, she prayed they would die.

But the sisters lived. Their mother’s employer, proprietor of a Brighton pub, saw a business opportunity. She bought the girls with the intention of putting them on public display.

And so the pattern of the Hiltons’ lives was set. Exploitation followed them throughout their lives. In the beginning, their owner, so to speak, Mary Hilton, was a cold, controlling woman. She forced the girls to take music and dance lessons so they’d be a more bankable stage attraction.

Traveling from England to Australia to San Francisco, the Hilton Sisters proved a goldmine. Meanwhile, their handlers kept them isolated. The girls received none of the huge income they generated.

“They were simply used,” an expert says.

“We signed contracts that were never read to us,” one sister says.

The sisters’ film appearances included “Freaks,” directed by the filmmaker who’d helmed the Bela Lugosi-starring hit “Dracula.” The brilliant “Freaks” is a classic now but American audiences rejected it in 1932 and its was banned in the U.K.

Even as the Hiltons’ careers dimmed and their incomes plunged, they continued working as best they could.

“Bound By Flesh,” in its odd way, is a story of survival. But it’s not a movie that can have a happy ending. Hats off to Zemeckis, though, for shaping the sisters’ strange, not as sad you might suppose, and sometimes amusing story into a film that’s fascinating like a car wreck.

‘Bound by Flesh’

CRITIC’S RATING: Three stars

STARRING: Daisy and Violet Hilton

DIRECTOR: Leslie Zemeckis

NOW SHOWING: 7 p.m. Thursday and Friday at the Manship Theatre, 100 Lafayette Street, Baton Rouge

RUNNING TIME: 1 hr., 31 min.

MPAA RATING: Not rated.

Excellent (4 stars), Good (3 stars, Fair (2 stars), Poor (1 star)