Warning: spoilers for Once Upon a Time in ... Hollywood will follow.

"What's the story?" young actor Trudi Fraser asks co-star Rick Dalton about the book he's reading during their lunch break in Once Upon a Time in ... Hollywood. "I haven't finished it yet," Dalton tells her. "I didn't ask for the whole story," Fraser responds. "What's the idea of the story?"

Audiences may at times struggle with that same question during Tarantino's latest film, which luxuriates in its stunningly deep recreation of 1969 Los Angeles. The story turns out to be far simpler than any of Tarantino's other work, which has always taken its time with dialogue but previously set it against the backdrop of exciting rescue missions or plots to kill Hitler. Leonard Maltin bemoaned the film as a "slow, meandering mess" and "just an elaborate time-filler," while Jezebel's Rich Juzwiak declared it a "long ramble." Salon's Gary Kramer described it as at times "sluggish," and NBC's Ani Bundel called it a "self-indulgent" movie that "meanders through Hollywood."

While some, upon hearing that Tarantino was directing a movie about the Manson Family murders, expected a pulse-pounding drama more in line with Inglourious Basterds, the director has instead compared Once Upon a Time in ... Hollywood to Alfonso Cuarón's Roma, a "memory piece" about the area where its director grew up that's not as much concerned with plot as it is with creating a mood and relishing its setting while following a day in the life of its central characters. Tarantino fully commits to this mission with three low-key storylines and with lengthy sequences that contribute to the sense of authenticity but wouldn't normally find room in a busier film.

We see Margot Robbie's Sharon Tate drive into town and pick up a book. We follow Brad Pitt's Cliff Booth during his entire commute to his trailer home, where he cooks dinner and watches TV. And Leonardo DiCaprio's Rick Dalton spends a full act making an episode of Lancer, with many, many uninterrupted minutes of this story-within-the-story.

It's not until near the very end that the plot picks up in the way we expected, with the arrival of the Manson Family to Sharon Tate's block and with Rick and Cliff becoming unlikely heroes. All the time spent investing in this friendship makes the final sequence unbearably tense, but only some of what came before turns out to have been essential for getting us there. For all the screen time the Lancer production eats up, it's the airing of Dalton’s appearance on a completely different show at the end of the second act that sends his career in a new direction and ultimately initiates the final plot sequence, meaning the elongated Lancer scenes don't turn out to be that important to the story.

But who says they need to be? The characters here are so sharply drawn and likable that we enjoy spending time with them, whether that time is crucial to the story or not, and every detail of 1969 Los Angeles is so thoughtfully considered as to make for the year's most immersive moviegoing experience, the film equivalent of wandering around in an open-world video game ignoring the missions and just enjoying the scenery and atmosphere.

Tarantino indulges himself a bit too much, to be sure. But the pure joy he's having using his encyclopedic film history knowledge to flesh out all corners of this universe, whether it's by executing a believable 1960s western or taking us on drives that highlight era-appropriate radio broadcasts and weather reports, is intoxicating. Besides, most of the so-called "sluggish" stretches do serve a purpose, whether it's showing Cliff's depressing home lifestyle or following Rick slowly regain his confidence and achieve the pure elation that comes from nailing a scene. Just because these bits don't all result in giant payoffs or fit together like puzzle pieces doesn't mean they're useless.

For Tarantino, the somewhat thin storyline was far from an accident. He once considered a more dramatic narrative for Once Upon a Time in ... Hollywood, only to decide that in this case, one wasn't needed.

"After I figured out who these guys were, I had to decide, okay, now what story do I want to tell with them?" Tarantino recently said on Today. "At different points, I'd had more melodramatic ideas. You know, more like an Elmore Leonard-y kind of story that would involve all these characters ... But after I figured out who these guys were, [I thought], I don't think I need a story. I think they're interesting enough characters. Let me just do a day in the life."

Of course, this isn't to say the film doesn't have any ideas. Just like Rick's book, the movie is about a man faced with the realization that he's not the best anymore and is becoming more useless each day. There's also the broader concept of 1969 as the year of a nationwide loss of innocence that the Manson murders would contribute to. Tarantino ultimately conjures a fairytale ending in which the tragedy never happens and Rick can become the best again, and with Sharon Tate getting the full life she was tragically denied.

Even without a complex story, then, Once Upon a Time in ... Hollywood is never boring for the same reason Roma wasn't. A movie sometimes can, in the hands of a master filmmaker, reach the point where the world it builds is so absorbing, the director's passion for the material comes across so clearly, and the characters and ideas are so strong, that the actual, minute-by-minute plot is a secondary concern.

For a filmmaker known for highlighting the kinds of little moments that normally take place off-screen in movies — hitmen chatting about burgers right before the exciting part of their day, or criminals having a debate about tipping the morning of their big heist — a film featuring about two full hours of a life's little moments feels right. Tarantino, in what he says will be his penultimate movie, has the confidence to rely almost entirely on character, setting, and mood to keep a film of his afloat. And in this case, Once Upon a Time in ... Hollywood sure does float.