For some years now, director Quentin Tarantino has been maintaining that his tenth feature will also be his last. While I don't actually believe that (artists retire when they die, no earlier), I suddenly find myself deeply hoping that he doesn't believe it either. Or maybe that when he says that it will be "his" last, he's referring to the old Tarantino, the gifted, self-satisfied pastiche artist whose bravura cinephilia largely set the tone for an enormous swath of indie filmmaking - shit, an enormous swath of all filmmaking, in many countries - in the 1990s and early 2000s. And then this Tarantino will be replaced by the new Tarantino who has come from out of the clear blue sky to make Once Upon a Time ...in Hollywood, being advertised as "the ninth feature" by the filmmaker (that number requires a bit of juggling over the definition of "feature"), though it feels enormously fresh and surprising, at this point in his career - it is less like any of the previous eight-ish features than any of them are compared to each other, by far. And so, I live in hope that he's just plain lying about those ten features, because I would really hate for this to be the penultimate Tarantino feature, just as he's starting to get really interesting, having made a film that I am refraining from calling the best of his career solely because I think that's a stupid thing to say until I see it at least a second time.

I mean, no hate for his best earlier films, but those are a good ways behind him now. All of his 21st Century output has felt like he's been humming on autopilot. Sometimes, that autopilot has produced utterly superb movies, like the Kill Bills of 2003-'04 but even those are close to a generation old at this point. And in the 2010s, the director has almost completely lost the thread: 2012's Django Unchained was a stiff, sluggish miscue whose problems have only become more obvious with age, and while I personally thought and continue to think that 2015's The Hateful Eight was a step in the right direction, I have never once felt any urge to re-watch it. The problem with both films, I am confident, was the loss of Sally Menke, Tarantino's editor on every one of her films prior to her untimely death; he replaced her, sensibly enough, with her Kill Bill assistant, Fred Raskin, but editors aren't like spare lightbulbs. The sockets aren't standardised. And Raskin's most obvious contribution to Tarantino's cinema has been a distinctive stripping-away of energy, leaving in the bloated sluggish bits that Menke knew how to remove, allowing conversations to walk by instead of race.

...Hollywood doesn't fix these problems. It instead leans into them, and makes a certain kind of stately slowness its purpose, rather than its handicap (you can tell they were trying to figure out how to do this with The Hateful Eight, and didn't quite get there). What the film is - and this incredibly salient fact has been more or less eaten alive in the critical discourse around whether or not we should be wringing our hands about what it does with the legacy of Sharon Tate - is a deliberately still, aimless meander around Los Angeles for two days in February 1969, during which nothing much happens of particular historical consequence in the lives of three people connected to the entertainment industry. These are Rick Dalton (Leonardo DiCaprio), the star of a 1950s TV Western called Bounty Law, whose unreliability (augmented by drinking) brought a premature end to the series, made him a small pariah, and has left him stranded as a villainous guest star in various other TV Westerns; Cliff Booth (Brad Pitt), who persists in thinking himself a stuntman despite the fact that he's a very large pariah thanks to the widespread assumption that he murdered his wife (the film is effortfully noncommittal about this, and if there's one subplot that seems obviously worth cutting out, it's this one), and who presently works as something very close to Rick's valet and best friend-for-hire; and the aforementioned Sharon Tate (Margot Robbie), a starlet whose career is hopefully about to get a boost thanks to the release of her new vehicle The Wrecking Crew and her marriage to white-hot director Roman Polanski (Rafał Zawierucha), with whom she's just moved into the house next door to Rick's. For two days, spreading across at least the first two hours of the 161-minute film, they go about their business. And that's, like, it. Some of the business is extremely important, personally: Rick has just been presented with the poisoned chalice of an offer to headline Italian Westerns by producer Marvin Schwarz (Al Pacino). Some is extremely not: Sharon spends a day traveling to Westwood to pick up a first edition of Tess of the d'Urbervilles for her husband, an errand we see play out in some detail before she stops into a sparsely-packed theater to watch herself in The Wrecking Crew.

None of that's the point. It's not a plot movie. What it is, and it's not hiding it, is an act of nostalgia so potent that it recreates an entire universe for us to play in. In the winter of 1969, Tarantino was five years old and living in Los Angeles, and Once Upon a Time ...in Hollywood is his attempt to bring back everything he remembers about what he clearly regards as a lost Golden Age. But not, like, a dewy, saccharine, romanticised Golden Age. His film's depiction of that place in time luxuriates in all of the most quotidian banality of daily live, aided incomparably by the efforts of costume designer Arianne Phillips, production designer Barbara Ling, set decorator Nancy Haigh, and cinematographer Robert Richardson, the last of whom basks in the veneer of film grain that allows him to create a thick haze to add to the film's evocation of the gritty, smoggy L.A. air. Not to mention the heroes involved in scrounging up all of the old radio commercials that somehow end up being the single most important aesthetic component of the whole film. After a career spent creating thoroughly artificial worlds to play in, Tarantino has switched around to create something tangibly, exhaustingly true: true to his experiences, if not maybe completely true to the reality of all the other people living in the city in those days. But it does not have the glow of a child's sweetened memories. This vision of Los Angeles is bracingly physical, graspable, livable: I genuinely can't think of the last movie, in any genre and in any setting, to do such phenomenal work of creating a fully realised space and then just letting us soak it in.

Because that's all this is, for at least those first two hours. We go to Hollywood and the surrounding places, and we just sink into it. Some of this has the unmistakable tang of Tarantino-the-film-buff greedily re-creating the rhythms of a working Western backlot; some of it involves unbridled cinephilic tourism. All of it is covered with a potent sense of loss and autumnal regret, brand new emotions for this director: he is finally making his Old Man's film, the one where he realises that he's already been alive for longer than he will be alive in the future, and tries to come to terms with what the passage of time means. This is an astonishing swerve for a man whose filmography till now has seemed the labor of a perpetual 17-year-old, and it works outstandingly well. For one, he's picked as his two male leads a pair who are themselves consumed by regrets, guilt, might-have-beens, and other troublesome memories. One of the things that ...Hollywood does best is to invisibly drift into flashbacks and fantasies, virtually none of which are clearly marked out: only Rick's daydreams about the time when he was in contention for Steve McQueen's role in The Great Escape for about ten seconds are obviously marked out as separate from the overall flow of images, and that's primarily because the digital witchery used to place DiCaprio into the 1963 film isn't quite ready for prime time. The only thing that makes these reveries stand out is that they're somewhat more excessively theatrical (most notably Cliff's tetchy, career-ending run-in with Bruce Lee (Mike Moh), presented in a floating single take), giving us the impression that Tarantino's leads, much like Tarantino, think in movies; their perceptions are cinematic rather than psychologically expressive. This is never clearer than in the film's obviously best scene, when Sharon goes to watch herself in The Wrecking Crew: the young woman doesn't have the lifetime of memories yet to feed off them, so the film obliges by allowing the movie itself to serve as her memory, with Robbie preening in delight at the laughter of the small crowd as she watches with pride at a job-well done, while we watch the actual Tate in footage from the (rather awful) Dean Martin action-comedy. It's the most loving depiction of the emotional transport, the realer-than-reality sense of sitting and watching the world onscreen that Tarantino - surely our loudest film buff among modern directors - has ever staged. For that matter, that sense of real life only getting realer when it's in a movie is kind of the motivating force behind Once Upon a Time ...in Hollywood itself; 1969 is 50 years gone, one day the people who remember it (including Tarantino) will be dead, and so will their memories, but this movie has given life and vitality to those days as though they're happening right outside the walls of the theater.

Is is, all told, an enormously generous film, by miles and miles the most generous that this somewhat ironic, acerbic director has ever made (the almost complete lack of irony in ...Hollywood, outside of some hilarious late jokes at the loving expense of the Italian genre film industry, is almost as shocking as the tangibility of Tarantino's sense of being middle-aged). Generous towards his characters, be they washouts and fuck-ups or be they Sharon, whose brutal murder in August 1969 is obviously one of the key events in Tarantino's personal mythology. For after all, if you buy into the death of the '60s myths that this film plainly believes in, your choices are the butchery perpetrated by the Manson Family over two nights that month, of which Tate was the most prominent victim, or the violence that ended the Rolling Stones concert at the Altamont Raceway that December, and Tarantino was obviously going to go with the cinema-centric event. At any rate, the film is among its many guises a straight-up paean to Tate, adoringly watching as Robbie inhabits her blissfully going about her life without any sense that she's been cursed with a doomed fate.

Even beyond that, the film is simply fascinated by and in love with its characters as examples of humans just sitting there, existing. By virtue of staying small and watching them do basic, simple things (run lines, buy books, fix an antenna), the film gets to see them without the pressures of drama pressing against them. The result is the career-best performance for all three leads, though Pitt I think is best in show; still, Robbie's facial expressions in that theater are the best visual acting, and DiCaprio's performance of Rick's stutter is the best bit of business, in large part because the film absolutely refuses to do anything to call attention to it, or get in our way about wondering what it might have to do with his choice of career (does he act to overcome the stutter? Is the stutter part of his anxiety about his career? Side-effect of the drinking? It is alarming how satisfying it is to have not the vaguest hint of an answer).

The film is also generous, excessively so, to its viewers. Tarantino has always had the heart of a video clerk, and so many of his films read as checklists of recommendations: Kill Bill and Jackie Brown especially, but it's right under the surface of every one of his movies. Now, for the first time, he's not just telling us what he loves: he's sharing his love, letting us experience the textures of life that made him fall in love with movies and moviemaking. It is an almost unnervingly intimate look into his heart and soul, the most open and inviting that he has ever been, surely, and about as open as I think it's possible for a filmmaker to be. He's asking us to come play inside his childhood, and everything about the look and sound of that place is rich and warm and full of life, even as it is covered with the awareness that things can't last. It's a film that celebrates as much as it mourns. There are moments that are keenly aware of loss, sometimes in surprising ways: I would never have expected to come as close to openly crying as I did during a moment when Tarantino and Richardson film a big Hollywood party with a roving crane shot, hovering over the setting like Scrooge clinging to the hem of the Ghost of Christmas Past, that follows as Sharon delightedly bumps into "Mama" Cass Elliot (Rachel Redleaf), and we simply hang there as two of the most upsetting victims of premature death in all of American pop culture laugh and dance, helpless to warn them or do anything to save them. Plus, the specter of the Manson Family hangs over the film, sometimes only in the most elliptical way, though it bursts into the foreground in the film's obvious second-best scene, when Cliff visits the Spahn Ranch, where the Family has been camping out. It's a masterful bit of thriller filmmaking, in a perverse mirror way: the build-up of tension is delicious and Hitchcockian and all, and then it deflates so hard that it almost feels more distressing when there's suddenly no tension driving the action than when the film was heaving with it. That sense of the omnipresent possibility of violence that never quite resolves into the fact of violence feels exactly the right fit for a story about a world that was already gone - the "classical Hollywood" that the film celebrates was already tottering by the late '50s, and by the late '60s it was a bloated, rotting corpse - but didn't know it yet.

But for every bit of sadness, there is a joyful laugh at the bright colors and the dazzling mechanism of The Entertainment Industry, as the film looks with amazed pleasure at the world it has created, and asks us, even if this couldn't last and was already mostly dying by 1969, isn't it wonderful that it existed at all?

Anyway, that gets us through the first two hours. You can't talk about the rest without a spoiler alert, so here it is. Stop reading if you don't want to be spoiled. This was already a 2000-word review, you have plenty to chew on.

So the last 40 minutes are another single day, the day that ended with Sharon Tate's murder. It's no mistake, I think, that the Tarantino who has been mostly absent suddenly comes roaring back: we get some Kurt Russell voiceover, we get crazy visual jokes about Italian Westerns (including a poster of a film title that made me laugh till I snorted, helped by Russell's very stentorian enthusiasm in reciting it), we of course get appalling geysers of violence - maybe the most brutally bloody scene this violence-loving director has ever crafted. Which is, of course, his rage manifesting: these evil, evil fucks ruined my innocence, the film seems to say, and if all I can have is this made-up fantasy (the film's title turns out not to be a reference to Sergio Leone, like everybody in the world would have reasonably assumed; it's because the film expressly presents itself as a fairy tale in which Good Triumphs, not because Good ever actually does that, but because we'll sleep better if it did), that's enough. It makes so much sense that a grand love letter to the Hollywood machine would knowingly, willfully, and perhaps even inappropriately recreate the most Hollywood touch of all: the happy ending that makes no sense according to any logic but the needs of being satisfying storytelling. Tarantino the documenteur and memoirist has no more place. Tarantino the razzle-dazzle spectacle-slinging overgrown kid and gore aficionado needs to come back, because that is how this story is made satisfying: by becoming a big, burly capital-M Movie. It tells us a lie, because that's what we want, and the idea seems to be, as long as we all know it's a lie, what's the harm in agreeing to that lie for a few hours? For that's kind of all that cinema is: an elaborate way of telling satisfying lies. And this ultimate movie about the love of movies could never end any other way.