Imagine Agatha Christie’s “Murder on the Orient Express” if nobody tried to figure out who the murderer was, and you have some sense of what an impact Michelangelo Antonioni’s “L’avventura” had on world cinema in 1960. While critics and audiences expecting a mainstream mystery were frustrated, the film quickly gained a reputation as a bracing and elliptical new style of narrative.

Not surprising that the Criterion Collection made Antonioni’s classic among the first it released on DVD. But the film is back in a wonderful new Blu-ray edition this month in a new 4K digital restoration.

The film begins with what we think will be a love triangle of sorts. Anna (Lea Massari) and her best friend Claudia (Monica Vitti) have agreed to join Anna’s boyfriend Sandro (Gabriele Ferzetti) on a cruise off the coast of Sicily. The relationship between Sandro and Anna seems fraught — in an early scene, they tussle warily in Sandro’s bed while Claudia waits outside, wondering what is going on. That sensation — of wanting to know the unknown — surfaces later on.

While on the yacht with some rather fatuous rich people, the trio go exploring a craggy, barren rock of an island. And then, suddenly, Anna isn’t there. No scream, no signs of struggle, no nothing. She’s just — gone.

What happened to her? Did an angry Sandro kill her? Did a jealous Claudia? Or did Anna get spirited away, of her own free will or not, on a passing fishing boat? Antonioni drops a few clues, but as the cruisers desultorily search the island, the answer is clear — none of the above. What happens to Anna we will never know, and shockingly, the characters don’t seem to care all that much.

The film then shifts to Sandro and Claudia, who on the journey home start a love affair with the spectral presence of Anna hanging over them, reminding them that life is fleeting and unfair. In a film that’s about absence more than presence — absence of love, absence of hope, absence of dialogue often — Anna in her absence has more of an impact on “L’avventura” than she had when she was on screen.

Sandro is a rather boorish figure, as when he callously knocks over an inkwell on a sketch artist’s drawings, chalking his cruelty up to accident. That’s the universe of “L’avventura” in a nutshell — cruel or indifferent. It may not matter which one.

The film gets quieter as it progresses, Antonioni lingering long on Vitti’s expressive face, the patches of dialogue further and further apart. “L’avventura” was enormously influential on the notion of an “arthouse film,” and you can feel its impact on everything from Gus Van Sant’s “Gerry” to Wisconsin filmmaker Brandon Colvin’s “Sabbatical.”

The Criterion disc includes a commentary track by Gene Youngblood, a visual essay by filmmaker Oliver Assayas (“Carlos”) and some of Antonioni’s writings, read by Jack Nicholson (star of Antonioni’s “The Passenger,” which played last weekend at Union South).