Stranger things: "Picnic at Hanging Rock" at 50

1975's Picnic at Hanging Rock reaches fifty, and its mysteries endure. Maybe even intensify: this reissue is the first time the film has played in UK cinemas with a 12A rather than PG certificate, a consequence of some racial language that wasn't picked up on first release, and possibly the fact we're getting the shorter Director's Cut, only enhancing the prevailing air of spookiness. (Whole scenes and sequences have vanished into the ether.) This was Peter Weir, at the outset of that Australian New Wave that gave us the films of Bruce Beresford and George Miller and Gillian Armstrong and Jane Campion, attempting to upend the costume drama and all its attendant certainties and complacencies in filming Joan Lindsay's non-fictional novel of 1967 about a trio of schoolgirls who go missing on Valentine's Day 1900 during an excursion to the striking outcrop of the title. We've all been thinking a lot about David Lynch these past few weeks, and you can't help but wonder whether he saw this widely circulated film at a formative moment in his directorial career. Picnic opens by paraphrasing Poe ("all that we see is but a dream within a dream"), and that dreaminess is exactly how Weir films this book: in gauzy, half-remembered images - a human caterpillar of sylphs lacing up one another's corsets, bodies hanging out of holes in caves - set to the kind of Gheorghe Zamfir panpipes that were just beginning to pierce Western consciousness. The raw material is Victorian formality and decorum. "As the day is warm," headmistress Rachel Roberts informs the girls before departure, "you will be permitted to remove your gloves once we have passed through Woodend". But we're invited to watch as that rationale is exposed by sunlight as impotent, meaningless and ridiculous, yet more silly rules our ancestors made for themselves.

As in Lynch's work, we're not meant to solve the mystery so much as contemplate it, though inevitably everyone will have their theories. (5/1 some sort of St. Valentine's Day massacre; 11/2 the girls, overwhelmed by adolescent passion, liberated themselves like aliens returning to their home planet. Stranger things have happened.) The film is most effective as an exercise in languorous atmosphere - immersive cinema before anyone thought to arrive at that specific formulation. Weir and cinematographer Russell Boyd allow us to both see and feel the heat and hear every last bug chirruping in the eerie silence after the girls go AWOL, while endowing us with a heightened, quasi-architectural sense of the sternly indifferent, often plain forbidding rock everybody runs into like a black brick wall, an organic variation on Kubrick's 2001 monolith. Yet Weir identifies a secondary site of interest: the people in this story, and the mysteries they too contain. Young men look at young women, not knowing what to make of them; the schoolgirls look at one another, attempting to figure themselves out; the adults entrusted with their care wrestle with grief, obsession, regret and suspicion they can't fully process. There may be nothing more mysterious here than the sight of life going on as quote-unquote normal: the survivors getting older and ghostlier, chained to this past, while the missing girls apparently remain the same age they always were. There is something unnatural going on of which we're never made aware, and which likewise lies beyond the characters' grasp. What year is this? Weir would go on to work with more assured performers - a slight liability: the young and inexperienced cast - but it actually benefits Picnic that nothing is fully nailed down or tied up: it's seemed like a completely different film every time I've seen it, as my own experiences align with a different generation of characters. A half-century on, it presents less like history than a premonition of what was to come, both from the Australian screen industries (among the chaperones: Vivean Gray, later Neighbours' Mrs. Mangel, already as weathered as Hanging Rock itself) and from Weir, pushing onwards into the metaphysical, before the movies grew uninterested in such matters.

Picnic at Hanging Rock returns to selected cinemas tomorrow.