The Leftovers, a show about the end of the world, opened its final season by declaring the world wasn’t going to end. That was the gist of the prologue, in which a 19th-century doomsday prepper kept prepping when doomsday didn’t come. That was the gist of the premiere’s puzzling, haunting flash-forward to a decades-older Nora Durst, now living in rural Australia. And that was the gist of the most recent episode, an hourlong head trip in which a man saved himself and nobody else.

When Kevin Garvey, on this Sunday’s penultimate "The Most Powerful Man in the World (and His Identical Twin Brother)," drowned himself to induce his third vision quest to what may be the underworld (or just his own subconscious), there was a storm brewing. The downpour seemed to confirm his own father’s outlandish interpretation of the Departure and subsequent events: that a Biblical flood was coming, and the only way to stop it was for Kevin to retrieve the final component of a rain song from a dead Aboriginal elder named Christopher Sunday. Kevin manages to track Sunday down — in this strange alternate universe, he’s the prime minister of Australia — but once he does, our hero admits he never believed Kevin Sr.’s theory. Kevin doesn’t even try to save the world. He condemns it, triggering a nuclear apocalypse to put humanity out of its misery. If Kevin Garvey’s journey had any greater significance, it stood to reason, he’d wake up to a world that had joined him underwater. Instead, he reemerges into a beautiful day in the Outback.

On any other show, this moment would come as a revelation. The wool would be pulled from our eyes along with Kevin’s; we’d be forced to reckon with the magnitude of what our pattern-starved brains can conjure up, as Kevin Sr. appears to at episode’s end while he has a good think on the rooftop. Instead, the moment lands with the fatalistic thud of a tragedy reaching its predestined conclusion.

Since the start, The Leftovers has thrown together a patchwork of irreconcilable worldviews, using the breadth of an ensemble-cast TV show to force the audience into confronting the limits of any single cosmology long before Kevin did. The audience has steeped itself in Kevin’s low-grade messiah complex; they’ve also seen the ritualized nihilism of the Guilty Remnant, and the fanatic anti-mysticism of Kevin’s friend John Murphy. Once-bedrock beliefs have turned on a dime: Kevin’s ex-wife, Laurie, left the GR to become a measured rationalist and, when that didn’t work, lost her will to live; true believer Matt Jamison abandoned his faith entirely in the space of a single episode. These characters can’t all be right. There’s a distinct possibility that none of them are.

So the world isn’t about to end, much as our heroes might want it to. It’ll just keep going, and they’ll have to keep living in it. Such is the natural conclusion of a show that dramatizes concepts it’s nearly impossible to hinge a drama on: doubt, ambiguity, and not just the tantalizing possibility of an answer — the deeper certainty that there is no answer. Even before Sunday’s final send-off, The Leftovers has spent its conclusion firming up the evidence that the Departure was always more fantasy than foreboding. The Leftovers denies both its characters and its audience closure, and spins that seeming handicap into great art.

Tom Perrotta, author of the 2011 novel on which The Leftovers is based, custom-designed the Sudden Departure to drive people insane. The Departure isn’t a happening so much as an un-happening: quietly, quickly, and without warning, millions of people simply ceased to be. The most important, far-reaching occurrence in human history could happen while you were distracted at the laundromat, which is exactly what happened in the TV adaptation’s opening scene. And just like that, the characters went from a world they more or less understood to a world no belief system could explain. They didn’t even have the luxury of watching it happen.

The show, cocreated by Perrotta and Lost’s Damon Lindelof, uses TV’s extended, multi-volume format to build on the novel’s themes of lasting trauma. Perrotta’s book showed how the Departure still loomed three years on, but a show could pursue that idea even further into the future, examining the world beyond the Westchester County suburb of Mapleton, New York, and families beyond the Garveys.

It’s no coincidence that critical praise for the show, while never lacking, experienced a noticeable uptick once The Leftovers moved past the first season, full of faithfully adapted events from the novel. In seasons 2 and 3, the show adjusted its tone — once somber to the point of being morose, now frequently punctured by surreal gallows humor. More importantly, it expanded its scope to the kind of epic scale that television can shoulder. Having used the Garveys to establish in Season 1 how the Departure affected people individually, The Leftovers zoomed out to the untouched hamlet of Jarden, Texas, to observe how it affected them collectively. (Rechristened "Miracle," Jarden attracts a vast array of pilgrims with agendas ranging from "tourism" to "worshipping Gary Busey.") And where the book ends on an optimistic note, with Kevin and Nora forming a makeshift family with the infant left on Kevin’s doorstep, the show chose to follow them into their happily ever after until it inevitably fell apart. To tell a story about how there are no easy solutions to loss, The Leftovers turned to a medium already given to extended narrative and open endings.

There’s also a meta slant to the premise, both in the context of a TV landscape saturated with mystery box scavenger hunts, and as the concept specifically applies to The Leftovers’ cocreator, the man behind what remains the ultimate mystery box show. There are obvious reasons a show not about seeking answers, but accepting their absence would be attractive to Damon Lindelof, who was literally hounded off the internet for failing to stick Lost’s 2010 landing. From the start, Lindelof’s premise prevented a jilted viewership: This was not a show that would provide solutions to its central mysteries. Along the way, The Leftovers inadvertently became a solution to, or at least a respite from, pop culture’s solution addiction. In a TV ecosystem consumed by figuring out either what’s already happened or what will, it’s a relief to have a show that can’t be cracked — and one where cracking it is beside the point. The Leftovers has discovered the creative potential of exploring the fallout of a climax rather than the buildup to one.

On the traditional spectrum of high to low fantasy, The Leftovers’ fantastical elements operate on the lowest level possible while still technically qualifying as supernatural. The result is more unsettling than expository, establishing a tone rather than laying down a ground rule. With this show, magic appeared just long enough to make itself felt, everywhere and to everyone, as a destructive force that could recur at any time — or never again. Who knows? The Departure underlies everything that unfolds on the show while remaining stubbornly unseen. More frustrating still to those affected, the Departure remains the only definitively supernatural occurrence in three full seasons of the show; Lindelof and Perrotta have remained adamant that everything we’ve witnessed since, including an apparent trip to the underworld, can be interpreted as either vision or delusion with equal validity. This is a world in which anything can happen, but no one will ever be sure if it did.

Just like starting a drama after the most dramatic thing that will ever happen to its characters, and just like giving away the fate of the world while building up final-season suspense, basing the bulk of a show’s action on things that might not even be happening is a method of storytelling that seems doomed to fail. (Or, at the very least, seems like a method designed to thwart viewers inclined toward second-guessing.) And yet The Leftovers pulls it off, because the persistent ambiguity over its basic reality gradually shifts the show’s big question from What’s happening? to What does this mean to the person it’s happening to? The Leftovers will never enlighten us when it comes to the mystery at its center, but the show is rigorously specific about the motivations and decisions that mystery inspires. The depth and intricacy of The Leftovers’ characterization is what saves the show from it’s-whatever-you-want-it-to-be! laziness and elevates it to the world’s most devastating thought experiment.

The same week-after-week quality that makes TV friendly to long-term narrative also proves hospitable to thorough character study. Even by the standards of its medium, however, The Leftovers is an unusually character-driven show. The most widely praised episodes of its divisive first season, "Two Boats and a Helicopter" and "Guest," were also the chapters that focused on individuals (siblings Matt Jamison and Nora Durst, respectively) and their post-Departure psychoses. By Season 3, Lindelof and Perrotta have broadened that approach to include nearly every episode, with each hour zeroing in on the unsteady equilibrium a character has achieved in the four years since we last saw them: Kevin, Nora, Matt, Kevin Sr., and Laurie have each taken a turn in the spotlight, the latter two for the first time.

Consequently, The Leftovers has become less focused on plot. Both the first and second seasons climaxed in acts of emotional terrorism — designed to inflict maximum fear and confusion, but without a body count — by the Guilty Remnant. Initially, the GR provided an external source of activity to at least partially offset the rest of the cast’s inner turmoil. While Kevin wrestled with abstract questions like "Am I really seeing the ghost of the woman I buried in the woods or am I just haunted by my own guilt?", the GR acted as a more direct source of suspense and conflict: What are they planning? How will they pull it off?

Season 3, on the other hand, promptly and literally blows the Guilty Remnant up. (A hush-hush government drone strike takes out their Jarden home base in a move that’s part transparent plotting, part world-building. The Leftovers conveniently writes off an entire subplot while making a point about America’s new normal.) There’s no longer anyone antagonizing our main characters except the main characters themselves. The Guilty Remnant’s stated purpose is to act as "living reminders" of the Departure, ensuring that efforts to escape or forget it fall short. And yet their absence indicates that the chain-smoking, silent vigils, and all-white outfits were never necessary to keep the Departure at the forefront of people’s minds.

Each individual episode of Season 3 has only barely moved the larger story forward, getting one character at a time to Australia so they could bear witness to Kevin and Nora’s long-brewing implosions. The episodes have, however, detailed each character’s enduring damage with an extraordinary level of nuance. Matt and Kevin Sr. have turned themselves into the heroes of their own epic mythologies. Nora clings to the loss of her children even as she rips away any other life rafts she can get her hands on. And Kevin Garvey remains stuck in the middle, his face permanently frozen in his signature expression of stunned silence. The Leftovers is the rare series where such a direct trade-off — plot for character — has actually paid dividends. What the third season lacks in forward momentum, it makes up for in contextualizing the events we do see. When Kevin and Nora fight in Episode 4, they’re unloading hours and hours’ worth of self-destructive commitment issues (his) and self-destructive martyrdom (hers). It’s a breakup that feels like a cataclysm.

The only explanation that works for the Departure, or a cosmic order that allows the Departure to happen, is that there is no explanation. The universe isn’t cruel; it’s simply uncaring. That’s an unusual stance for a show to take, given that fiction typically distinguishes itself from reality by providing the kind of order The Leftovers pointedly withholds. But it allows for an equally unusual insight. The worst-case scenario — for people, for civilizations — isn’t an unhappy ending, it’s no ending at all.

The Leftovers overcame the vacuum at its core by turning its attention from action to reaction, from a crisis to the ways, at once obvious and unpredictable, that people buckle under pressure. An uptick in cult membership is a logical consequence of the Departure; that those cults would center on magical hugs or an unusually virile lion is not, at least until the show works backward to explain how these new faiths have the ring of truth, or at least make for a decent placebo. And after three seasons of tracing the seemingly infinite spider cracks in post-Departure mankind’s collective psyche, The Leftovers has arrived at a definitive takeaway from a world where "definitive" no longer exists: Belief lies in the heart of the believer, and as long as that belief helps you to get through the day, you might as well go all in.

When Kevin finally makes contact with Christopher Sunday, he doesn’t frame his request for information in terms of the potential flood, or even himself. It’s about his father. "He needs this," he says, with all the urgency of someone who really does think they’re saving the world. What he means is that Kevin Sr. has to maintain the sense of agency he’s created for himself in a world where agency no longer exists, and that upholding such a sense of purpose is as noble a goal as literally preventing the apocalypse. By plunging into purgatory once more, Kevin’s agreed to take part in a collective delusion, or maybe absolution. The Leftovers tells us that Kevin’s decision — commitment without belief — is its own kind of heroism, and that merely surviving is its own kind of struggle. The world doesn’t have to end for your own world to collapse in on itself, and a TV show doesn’t have to put the universe on the line to take us on a satisfying journey.

Disclosure: HBO is an initial investor in The Ringer.