With Tilda Swinton’s puzzled gaze as its guide, “Memoria” amounts to a haunting, introspective look at one woman’s attempts to uncover the roots of a mysterious sound that only she can hear. More than that, it’s a masterful and engrossing response to rush of modern times and the collective amnesia it creates. Anyone frustrated by its patience only serves to prove the point.

All of which means that “Memoria” is more meditation than movie, a transfixing deep-dive into the profound challenges of relating to people and places from the outside in. Jessica (Swinton) is already feeling out of place when the movie begins, as she abruptly awoken by a deep, explosive thump that materializes out of nowhere. A British botanist based in Medellin, Jessica travels to Bogotá to visit her sister (Agnes Brekke), whose husband puts her in touch with a sound engineer named Hernán (Juan Pablo Urrego). Describing the noise as both “a ball of concrete hitting a metal wall surrounded by seawater” and “a rumble from the core of the Earth,” Jessica works through a couple of options with her new friend until he more or less manages to imitate with his soundboard. But that doesn’t get her any closer to the root of the noise, or why it seems to haunt at the most unpredictable moments. The official explanation for Jessica’s malady might be “Exploding Head Syndrome,” which the director himself apparently experienced at some point in his life, but “Memoria” doesn’t dig into the hard science. Instead, it roams alongside Jessica’s quest in a kind of fugue state, deepening the sense of displacement that surrounds her until it reaches a stunning and strange revelation in its final act. Apichatpong’s filmmaking exists within the hypnotic quality that comes from sitting in silence, surrounding by diegetic sounds, for minutes at end until subtle details come to light. “Memoria” is the purest distillation of that: Despite a single CGI twist that may or may not be imagined, its most adventurous visuals stem from the immersive greenery of the Colombian countryside where Jessica eventually finds herself, surrounded by inexpressible details of people and history that preceded her arrival. Swinton’s distinctive physique is particularly effective in the story of a white woman roaming an alien landscape, a concept that gets quite literal as the story moves along. The performance plays like a prolonged homage to Maria Vetto’s turn in Lucrecia Martel’s “The Headless Woman,” another movie about feeling out of place with one’s surroundings as they continue to drift along. In this case, as Swinton gazes at her surroundings with a blend of shock and curiosity, the movie becomes an extension of her unsteady relationship to the historical resonance around her. As one man inexplicably vanishes from the plot (he literally ceases to exist) and another with the same name takes his place, Jessica begins to understand that the sudden, jolting noise haunting her head stems from a profound disconnection with her everyday routine. The sound tells a story, but it’s not her own.

This quest has a certain reflexive quality to it. The filmmaker is himself an outsider in a society that has a complex history of violence and class struggle. “Memoria” turns on the desire to understand those profound layers of national identity while acknowledging that some answers will always remain shrouded by the inscrutability of the past. Just as “Uncle Boonmee” alluded to its country’s history of political violence through supernatural events, “Memoria” uses its intricate sound design — and one very weird, very fleeting sci-fi twist — to explore the way Colombia has modernized over the years, even as its indigenous roots remain hidden in plain sight. That contrast comes to light in the transfixing final act, when Jessica ventures to the countryside to check out an archeological dig and instead finds herself in a prolonged, sleepy exchange with a man who finally provides some measure of an explanation for her mental disorder. Their exchange pushes Apichatpong’s liberated non-narrative style to a certain extreme, with results so bold that could very well alienate all but his most passionate followers. But it’s an immersive gamble well worth the risk. By the time the movie gets there, Apichatpong has enacted a remarkable existential plunge. Re-teaming with cinematographer Sayombhu Mukdeeprom, the director brings his careful, mostly stationary compositions into a busier milieu than usual. “Memoria” spends its first half following Jessica through modern-day Bogotá, lingering on a prolonged jazz session at one moment, the busy city streets the next, and at one point sitting with an empty plot of greenery surrounded by glass. That last one is less metaphorical than poetic: It conveys a certain kind of emptiness filled by the rush of contemporary people and places, leaving no space to contemplate anything that came before them. But “Memoria” does. In his own precise, abstract manner, Apichatpong has made an ecological disaster movie about the danger involved in ignoring the natural state of things and the people who respect it. Jessica’s early encounters set the stage for the arrival of a parochial character afraid to engage with anything beyond the small, quiet environment at his immediate disposal. “Experiences are harmful” to his memory, he says, and by the time the movie arrives there, we can relate. The explosion that Jessica hears may be something out of this world, but “Memoria” remains firmly planted in it, hoping against hope to understand what it has to say.

Grade: A-

“Memoria” premiered in Competition at the 2021 Cannes Film Festival. Neon releases it later this year. Sign Up: Stay on top of the latest breaking film and TV news! Sign up for our Email Newsletters here.