In the searing heat of an Australian Valentine’s Day, a small party of schoolgirls set out for a local beauty spot, Hanging Rock. Some were never to return. The shocking incident, whether imagined or real, as some still believe, has haunted the national psyche ever since the publication of Joan Lindsay’s novel Picnic at Hanging Rock in 1967.

Regarded as a key work of modern Australian literature, Lindsay’s hypnotic puzzle soon spawned a classic film version that was to beguile and disturb audiences around the world.

Now the mystery at the heart of both the novel and Peter Weir’s award-winning film – the disappearance of three schoolgirls and a teacher from the fictional Appleyard College that hazy Valentine’s Day in 1900 – is to be looked at anew.

An Australian television series starring British actress Natalie Dormer in the role of boarding school headmistress Hester Appleyard is re-telling the fable over six episodes and will be broadcast by the BBC later this year. And next month a hit stage version of the book from Melbourne opens at London’s Barbican theatre.

Hailed by the Guardian’s critic as a show with “volcanic power” when it ran briefly in Edinburgh last year, director Matthew Lutton’s production updates the schoolgirls’ story and offers “a vision of psychological breakdown as a prettified illusion is ripped apart by the raw force of nature”.

Lindsay’s story has attained the status of a modern myth, exploring the clash between Victorian gentility and the burgeoning sexuality of the schoolgirls. Writing the book in a fortnight at the age of 69, the author claimed to have been inspired by dreams, although a recent book by Janelle McCulloch found some grounds for supposing the young Lindsay might once have heard about a real case of girls going missing at the landmark in the southeastern state of Victoria. Seeds of the story are also thought to have been sown by a 1875 painting of visitors viewing Hanging Rock by William Ford.

The BBC promises the new serialisation offers “a fresh take”, while its Australian producers describe their “re-imagining” as “modern, mysterious, completely gripping and visually spectacular”.

Dormer’s role as the headmistress has been expanded for television: “In her novel, Joan Lindsay gives you hints there is a past and that Hester isn’t being completely honest about her background,” Dormer has said. “The delicious thing is that we have really fleshed out her morally ambiguous background in London.”

The series has been directed for Foxtel by Walking Dead veteran Larysa Kondracki, whose Canadian nationality caused initial dismay in Australia.

Actress Rachel Ward said the decision was “a bitter pill” for Australian directors. “It’s ultimately just sad that those of us who have committed so many years as Australian film-makers are thought so little of by some production teams and broadcasters here that we must import someone to do the job for us,” Ward said.

When a 27-year-old Weir originally set out for Hanging Rock in February 1975 to shoot his film in six weeks, he wanted to recreate the “tremendous unease” he felt reading Lindsay’s novel.“I couldn’t wait to get to the rock to see if it was as good as it read,” he has said.

The eerie end result, an effect achieved by placing layers of bridal veiling over the camera lens, was what the late Observer critic Philip French described as “the first true masterpiece of the Australian cinema”.

In her book Beyond the Rock, McCulloch argues Picnic at Hanging Rock came at the right moment: “Australians were hungering for something that was quintessentially Australian. They wanted books and films that held up a mirror to the nation. It was perfect timing.”

At the core of Lindsay’s tale is the riddle of the disappearance, a point underlined by a junior editor called Sandra Forbes, who read the book early on and suggested that a final chapter which provided a spiritual solution should be deleted. The author agreed, and the enduring appeal of her story may now lie in the unanswered question it poses. Only an old man in her novel finally attempts to account for what happened that day at the rock.

“Nobody, can be held responsible for the pranks of destiny,” he says.