“Svaha: The Sixth Finger,” is what happens when a fairly straightforward horror tale is rendered convoluted by sidebars, detours and distractions. The end product is labored and drawn-out, losing the thread here and there and lacking the urgency to become compelling.

But as a disclaimer, I can pretty much guarantee you’re going to have an easier time getting through Jae-hyun Jang’s film, set among the competing faiths and “fake” faiths of South Korea and built around an intrepid debunker/investigator, Pastor Park.

For starters, the phonetic spelling of names on the subtitling is far removed from the way they’re spelled out on the Internet Movie Database. A character or two goes by more than one name, and as the cast is largely unknown in the West, well there’s a lot of time wasted tracking down who is playing whom.

Since it’s from the director of “The Priests,” it’s almost worth the trouble.

A teenage girl (Lee Jae-in) narrates. When she was born, Geum-hwa says,
“the goats wailed,” her mother died and Dad didn’t last for long either, and she arrived with one leg badly gnawed while she was in utero.

“A demon was born with me,” she says (in Korean, with English subtitles). That was back in 1999. And in the intervening years (the setting is 2014), wherever she, her grandparents and her “demon twin” live, dogs howl, rats flee, serpents congregate and birds hurl themselves at windows.

Nobody sees the twin, which wails like a scalded dog and is locked behind a door emblazoned with a cross. The film’s prologue includes a sort of cattle exorcism, and an exorcist chased away when he and a posse of locals show up to roust this new-family-in-town from their house.

In the present day, Pastor Park (Jung-jae Lee) is a media figure and journalist dedicated to unmasking phony religions. He’s a chain-smoking hipster who wears a crucifix and drives a Beemer, and with his under-cover aid Go Joseph (David Lee), he investigates cults, heretical strains of Buddhism, Catholicism, Adventists and (apparently) Methodists and publishes his findings in assorted religious magazines.

On occasion he consults in person with leaders of this or that organized religion, warning them of the con artists, pyramid schemers and Doomsday Cultists in their ranks.

His Far Eastern Religion Research Institute gets by on donations and the occasional headline-grabbing scandal as he seeks out false prophets.

The false prophets tend to get pissed. When we meet Pastor Park, he’s being egged by women in nun’s habits chanting “Stop your witch hunt!”

Pastor Park gets on the trail of this Deer Hill cult, which has its roots in Buddhism, claims to have an impossibly old leader, and dogma that relates to the wandering history of The Buddha and his religion.

The practitioners of this cult have a connection to the girl and her demon twin. There’s a sign, a “sixth finger,” that its members are on the lookout for.

And one acolyte, a blond true believer named Hang na and renamed Gwangbok (Jung-min Park) is on the trail of the wandering Geum-hwa, her demon twin and her family.

A cop (Jin-young Jung) is stumbling into strange goings on, a child buried inside a concrete bridge abutment, and Pastor Park. But Chief Hwang is a “Nothing to this, nothing to see here” skeptic.

They’re ostensibly all headed towards a dramatic climax one snowy Christmas Eve, somewhere in South Korea.

Jae-hyun Jang reaches for a goofy tone, here and there — the office work of a “church police” X-Files investigator, Nespresso gags, Mr. Go debunking his debunker boss’s theories of nefarious or at least “obscene” goings-on in this or that sect, etc.

But when the cultists self-flagellate, when Hang na and whoever is following his orders begin their “Beast will be born again” and “Wipe your tears and behold the truth” incantation, “Svaha” turns deathly serious and the stakes rise.

We rarely see this side of South Korea, away from the biggest cities, covered not just in the rainy grey gloom of “The Host,” but in snow-covered forests. The movies has a lovely chill about its look, with or without snow.

Pastor Park’s “investigation” leads him to others who give him insights into Buddhist tradition and myth — the Four Heavenly Kings, for instance.

The punch line to much of this, that the skeptic becomes a believer in that “Truth is out there” sense, is muddled, and the picture never gains much traction, tumbling to and fro among the assorted story threads.

Even the ostensibly “satisfying” horror film finale feels muted, like a cheat.

It’s not “The Priests,” but I’m still glad I took the time to check it out, and as I said, you might get more out of it than me. But measuring “Svaha: The Sixth Finger” against the tried and true “rules” and tropes of horror, Jae-hyun Jang ‘s latest comes up a finger or two short.

MPAA Rating: TV-14

Cast:Jung-min Park , Jung-jae Lee, Lee Jae-in , Ji-tae Yu, David Lee, Jin-young Jung

Credits: Directed by Jae-hyun Jang, script by Kang Full and Jae-hyun Jang.  A CJ Entertainment/Netflix release.

Running time: 2:04