“It is a period of civil war. Rebel spaceships, striking from a hidden base, have won their first victory against the evil Galactic Empire. During the battle, Rebel spies managed to steal secret plans to the Empire’s ultimate weapon, the DEATH STAR, an armored space station with enough power to destroy an entire planet.”

These words will be familiar to anyone who’s seen 1977’s original Star Wars (subsequently known under its revised title Star Wars: Episode IV – A New Hope). The passage appeared scrolling upward toward infinity during the movie’s opening title crawl—the now-traditional way that all seven numbered episodes (and counting) of the series have begun.

But director Gareth Edwards’ Rogue One is different than the Star Wars we’re familiar with. Billed as a standalone, Jedi-less story set apart from the numbered adventures of the Skywalker clan, it breaks with tradition, dispensing not only with the title crawl, but with the Star Wars logo itself. Pretty bold for a movie that nevertheless spends most of its 2 hour and 14 minute running time dramatizing the events described in A New Hope’s title crawl.

It’s technically a standalone film, but it still functions as a direct lead-in to the events of Episode IV, and in many ways, it’s a more satisfying prequel than series originator George Lucas’ official prequel trilogy, even if it takes a while to find its footing.

Part of what holds this picture back is the lack of a strong musical component—Oscar-winning composer Michael Giacchino had a scant four weeks to compose the score after replacing Alexandre Desplat in the 11th hour—or finely etched characters to earn our empathy. Overall, it may be better than last year’s Episode VII: The Force Awakens, with more surprises in store for faithful fans than director J.J. Abrams’ enjoyable but thinly veiled rehash of A New Hope. Nevertheless, Abrams caught lightning in a bottle when he cast series newcomers Daisy Ridley, John Boyega and Adam Driver, who more than held their own opposite the original trilogy’s stars, Harrison Ford, Carrie Fisher and Mark Hamill. We really grew to care what happened to them.

By contrast, the band of Rebels at the center of this film’s PG-13 action (much of it captured with handheld cameras by Zero Dark Thirty cinematographer Greig Fraser in another break from Star Wars norms) are a collection of character types who would feel right at home in a picture like 1967’s The Dirty Dozen, clearly an inspiration behind Edwards’ gritty war picture. Or at least they would, if they had personality beyond their sole defining traits.

Take Jyn Erso (The Theory of Everything Oscar nominee Felicity Jones). Another Star Wars protagonist with daddy issues, she’s broken out of Imperial prison by members of the Rebel Alliance, who need her help in tracking down Galen Erso (Mads Mikkelsen from NBC’s Hannibal), her father and one of the galaxy’s most brilliant minds. She’s got a chip on her shoulder, but you’d probably be a little angry if your beloved “papa” abandoned you and became the Galactic Empire’s version of J. Robert Oppenheimer, the reluctant architect of the Death Star.

She’s overseen by Cassian Andor (Y Tu Mamá También’s Diego Luna), a Rebel spy and an assassin who will always shoot first. His extensive combat experience is crucial to infiltrating an Imperial Security Complex on Scarif, a deceptively idyllic tropical planet that becomes a war zone during the film’s thrilling third act. It features the series’ finest example of a sustained space battle, intercut with a brutal ground assault—and that’s saying a lot, considering the Star Wars movies have collected multiple Oscars for their groundbreaking visual effects.

But first, we have to sit through the slow build of the convoluted first two acts, which introduce us to Bodhi Rook (an underutilized Riz Ahmed from HBO’s The Night Of), an Imperial cargo pilot who defects from the Empire to deliver a fateful message to Saw Gerrera (Oscar winner Forest Whitaker, dripping gravitas), a hardened freedom fighter battling on the outer fringes of the Rebellion. Rounding out the cast are Boston-bred Donnie Yen, who’s a standout as Chirrut Îmwe, a blind, Zatoiche-like spiritual warrior, and Chinese actor/writer/director Wen Jiang as Baze Malbus, Îmwe’s loyal protector. And last, but certainly not least, is Alan Tudyk (of the sci-fi series Firefly), who creates an indelible motion-captured performance as the computer-animated K-2SO, a droll, Rebel-reprogrammed Imperial Enforcer Droid who lacks a verbal filter. It says something about this film’s script that a robot is its best character.

But despite its flaws, Rogue One remains one of the franchise’s brighter efforts, ending on a tremendous high, due in no small part to a glorious extended cameo by Darth Vader. With fewer than 10 minutes of screen time, the Dark Lord of the Sith is presented as the villain fans have always wanted, but rarely seen. This may represent the ultimate case of fan service, but during its final moments, the film has finally given the faithful the prequel they always wanted.

Rogue One: A Star Wars Story   ***1/2

Starring Felicity Jones, Diego Luna, Alan Tudyk, Donnie Yen, Wen Jiang, Riz Ahmed, Ben Mendelsohn, Mads Mikkelsen, Valene Kane, Genevieve O’Reilly, Alistair Petrie, Jimmy Smits, Ian McElhinney, Fares Fares, Jonathan Aris, Sharon Duncan-Brewster, Duncan Pow, Daniel Mays, Beau Gadsdon, Dolly Gadsdon, Forest Whitaker and James Earl Jones. Written by Chris Weitz and Tony Gilroy, from a story by John Knoll and Gary Whitta, based on characters created by George Lucas. Directed by Gareth Edwards. At Assembly Row, Boston Common, Fenway and in the suburbs.