Gloriavale is the first ever big-screen documentary about a secretive, fundamentalist commune on New Zealand's West Coast.
The film struggles to find a new angle on the story that we haven't heard repeatedly over the years, says Simon Morris.
The Gloriavale community is an exclusive Christian cult founded by an Australian man who called himself Hopeful Christian.
But like most such groups, Gloriavale is extremely hierarchical. The leaders - who call themselves Shepherds - rule with an iron grip.
Everyone does what they're told. In the case of women, that means working every waking moment and having lots of babies.
The film Gloriavale centres on a man who was essentially banned from the group - John Ready - and his subsequent struggle to get his family out of there.
His story inspires a group of Christchurch lawyers to take Gloriavale to court, on the charges of, among other things, slavery.
We meet other people who managed to get out, including John's sister Virginia, and interestingly, a renegade Shepherd called Zion.
Over the years, more than 100 people have managed to break away from Gloriavale. And over the years I have heard this story, or variations on it, many times on TV.
The documentary picks up on the legal case brought by John Ready against the Shepherds, which is occasionally hard to follow. The case, which has been going on for years, is still unresolved.
One thing this film does offer is home movies of life in Gloriavale. They look like out-takes of an old Western - women in navy blue pinafores and bonnets, surrounded by dozens and dozens of kids, all under the watchful eyes of the leaders.
Only when someone takes in a secret device to record a meeting with the Shepherds does the iron fist in the gingham glove show itself.
They sound like figures from a fundamentalist church of two hundred years ago - which, I suppose in many ways they are.
When in doubt - particularly doubt over whether women are allowed to say anything - the Old Testament is regularly pressed into service.
Generally, most previous attacks on places like Gloriavale tend to take a predictable, anti-fundamentalist Christian slant. But it's interesting that this film isn't quite as... well, fundamentalist.
Smyth and Grady's last film was a Christian-friendly documentary about elderly pilgrims called Camino Skies. And one of the key figures in this film is John and Virginia's mother Sharon, who's still a member of Gloriavale.
My own criticism isn't that Gloriavale is some kind of fundamentalist cult, dedicated to antique dogma, so much as that it needs to be re-configured in a more open-minded way.
The film didn't tell me much I hadn't heard before and didn't answer the one question I went in with - "What were these people looking for?" And, I suppose, "What did they expect?"
Related:
Gloriavale's secrets and the fight for justice
Sharon Ready & Liz Gregory: standing up to the Gloriavale shepherds