What’s it really like to work on Saturday Night Live? Looking back over the years, this question has fascinated many: Countless books about the show and its stars have been written, while SNL alumni are constantly asked about their experiences. Perhaps the pinnacle of this fascination came in the fall of 2006, when NBC greenlit two different series about the behind-the-scenes antics at a fictional weekly late-night comedy variety show. (30 Rock would go on to be an Emmy-winning seven-season success, while the first season of Studio 60 on the Sunset Strip remains a fascinating failure.)

Jason Reitman’s new movie Saturday Night explores this question with a micro-focus on a pivotal time for the show: The 90 minutes before the first-ever episode was broadcast live to America, a nation unprepared for the kind of counterculture comedy dreamed up by a young Lorne Michaels (Gabriel LaBelle) and his pack of misfits. The vibe delivered by cinematographer Eric Steelberg’s freewheeling handheld camera work is pure chaos — a symphony of drugs, contract concerns, raging egos, exposed dongs, and most of all, the very special brand of anxiety specific to very funny people.

The casting is almost as dizzying as the action, with new talent mixed up with more established actors almost at random: One second, you’re watching young Nicholas Podany (whose credits include single episodes of Blue Bloods and Law & Order) pull off a pretty impressive Billy Crystal impression, and then Oscar winner J.K. Simmons swaggers into the frame as television legend Milton Berle, the ghost of a previous generation of entertainment.

Uncle Milty’s just one of the voices who’s telling Lorne that he’s going to fail, as Reitman and co-writer Gil Kenan’s script is peppered with naysayers. Like other based-on-a-true-story tales, the real tension around whether or not the show will go on is minimal, though the movie takes a subjective enough approach, with enough immediacy to the action, that the adrenaline rush is palpable.

Confining the film’s action to the exact length of time an actual episode of SNL lasts proves to be a brilliant choice, especially thanks to the way the script condenses and amplifies the drama over the show’s origins as a replacement for Tonight Show reruns. One really does manage to feel the potential that the plug could be pulled at any moment by NBC executive David Tebet (Willem Dafoe).

Tom Shales and James Andrew Miller’s Live From New York: The Complete, Uncensored History of Saturday Night Live as Told by Its Stars, Writers, and Guests, the epic oral history of the show’s first decades, is a clear touchpoint for some of the moments included here, and the film showcases remarkable accuracy when it comes to the line-up for that night’s first show, from host to musical numbers to what was cut right before showtime and why.

The film overall works remarkably well in its depiction of the vibes, the rush of live television. However, much like any episode of live television, it contains its flaws, such as punctuating too many moments with quick flashbacks to scenes that just happened a few minutes ago. There is also more than one “No one will remember who you punk kids are!” moment that proves overly self-indulgent — this movie would have ratcheted up at least one grade point if that temptation had been avoided.

And because of the dozens of characters packed into the narrative, a lot of the dialogue (perhaps out of sheer necessity) gets remarkably expositional. Even the most egotistical of actors don’t go around repeatedly listing off their past credits and where they went to school… Well, most of them don’t, anyway.

One of the best aspects of Saturday Night is the way it showcases not just the wild comedians running amuck. Attention is paid to the dedicated set designer desperately trying to finish the stage before showtime and the other artists working behind the scenes. And Rachel Sennott is the unsung hero of the film as writer/producer Rosie Shuster, the actual glue holding a lot of the show together (despite her complicated relationship with her husband Lorne).

It’s pretty tempting to go down the very long cast list, one actor at a time, and critique the degree to which they succeed at depicting the very famous figure they’ve been tasked to portray. One of the movie’s best surprises is Matthew Rhys as George Carlin, with The Americans star mirroring Carlin’s kind eyes as well as his cantankerous spirit, and recent surprise Emmy winner Lamorne Morris is also a standout as original SNL cast member Garrett Morris (no relation).

Succession’s Nicholas Braun is perhaps the film’s MVP with his dual role as Jim Henson and Andy Kaufman — while his screen time is so limited that his take on these men is in the realm of caricature, he proves convincing as both of them, despite their remarkable differences.

Gabriel LaBelle holds things together remarkably well as the focal point of the havoc — having previously played a young “Sammy Fabelman” in Steven Spielberg’s The Fabelmans, it’ll be interesting to see which vaguely-based-on-a-real-person wunderkind he’ll play next. It’s worth noting that LaBelle is currently 22 years old, while in real life Michaels was 30 on the day that SNL originally premiered — casting an actor who looks so much younger than everyone else involved feels like a deliberate choice on Reitman’s part, only amplifying the stark difference between the TV industry as it was in 1975, and what it would become in the years to come.

As a cultural institution, SNL has since evolved from its origins as revolutionary television into a mainstay of the comedy establishment. But the mythology of its wild early days remains a foundational part of the show’s power, and from the beginning, some of the show’s funniest moments were found in self-reflexively pulling the curtain back.

Because that’s ultimately what Reitman succeeds at with Saturday Night — capturing the allure that’s kept audiences tuning in for what will be 50 seasons, come September 28th, 2024. The sense that something magical is going on in a little studio called 8H. No one knows what will happen. But they want to find out.

Saturday Night arrives in select theaters on Friday, September 27th. Its wide release begins October 11th.