It takes Ridley Scott at least two hours and change to tell the story of how Patrizia Reggiani, a maybe social climber and  gold digger finagled her way into the House of Gucci.

Then it takes just a relatively short time to discuss how or why she had her ex-husband killed and she went to jail.

That’s a lot of time to build up to something that is then glossed over quickly. But I think Scott may have been mesmerized by Lady Gaga, pretty much the only appealing part of his long and often fact free movie. I know everyone else will be equally mesmerized by her.

You need to know the end of the story first: Reggiani is alive and well and out of jail despite hiring the hitman that murdered her ex, Maurizio Gucci, played by Adam Driver. In the movie, which opens on Wednesday, Patrizia and Maurizio eventually have a child, a daughter. In real life, they had two daughters. In real life, the Guccis were well divorced when Patrizia ordered the hit. Their settlement was finalized. She had nothing to gain and everything to lose. (The movie makes it seem otherwise.) She was either completely deranged or maybe there was something wrong with her.

It turns out, she did have a benign brain tumor. When she stood trial, there was much discussion of whether the tumor pressed against something in her avaricious head that caused her to make such a bad decision. None of that is in this movie. It seems like a major point, doesn’t it?

But let’s get back to “The House of Gucci,” a far cry from Ridley Scott’s’s really great, cleanly told 2017 movie “All the Money in the World” about the Getty family. That movie had a fully realized script. This one does not. The credited writers were not up to this task.

Luckily, Lady Gaga was: she got it. She went for it. She grabs the whole house of Gucci by the shutters and rattles it til the door knobs fall off. She gives a sensational performance clearly invented by her while everyone else tries to figure out what the hell is going on.

That would be: we have two Gucci brothers, played by Al Pacino and Jeremy Irons. Pacino’s Aldo — a real Al character, if you will —  has a dimwitted son (Jared Leto, over the top, LOL). Irons’s Rodolfo (the actor’s accent wanders like Marco Polo) has Adam Driver’s careful, boring, plodding Maurizio. (In real life, Aldo Gucci had three sons and a daughter. Again, a missing fact.)

Aldo knows his son is a fool, so invests in Maurizio to lead the next generation of the fashion house. He also decides he likes Patrizia, even though brother Rodolfo looks down his nose at her and doesn’t trust her. Rodolfo is correct but he’s the brother enjoying the fruits of everyone else’s labors. He lives in a castle surrounded by tapestries. Aldo is the garmento who makes the deals and gets things done.

But “House of Gucci” is a bit of a House of Cards. Is it about the murder? Or is it about the family? Scott is so fascinated by the long linear roll up to the murder he should have made a miniseries. Patrizia and Maurizio marry, Rodolfo kicks them out, Aldo brings them back. She has no business experience but is right in the middle of everything. The company falters, Maurizio grows tired of her and leaves her for another woman. Why? How do I know? It’s not explained! Marone!

The standout in the massive cast of supporting players is Salma Hayek as Pina Auremmia, a psychic and bloodsucker who helps Patrizia set up the hit. She recurs throughout and is a clear note in a cacophony. I also liked seeing Reeve Carney, from Broadway, as a young Tom Ford. Of all the colorful main players, it’s an unrecognizable Jared Leto people will remember as Paolo, a needed distraction covered in prosthetics and regret.

Adam Driver looks the part of staid, clueless Maurizio, but when he’s killed no one is unhappy. He isn’t missed. Maurizio, not a visionary by any means, sells the family’s legacy to a corporation. He’s a one dimensional character. He just seems greedy and a little stupid. When he and his next wife (“Call My Agent”‘s Camille Cotin) are on screen by themselves, all the air rushes out of the movie. That’s how much Gaga informs the proceedings. Her Patrizia is right (and so did Aldo see somethign in her): without her, they are nothing. She is more Gucci than the Gucci’s.

“The House of Gucci” is no “Gotti,” it’s not a disaster. This is Ridley Scott, after all. But it’s neither so campy you can make fun of it, nor serious enough to be “The Godfather.” It’s trapped somewhere in between. It’s under cooked, I think, because like another MGM movie this fall, “Respect,” the writers were not well versed in the material. They depended on the actors to fill in the blanks. (Jennifer Hudson did that for “Respect.” Gaga does it here.  “House of Gucci” proves she can act up a storm and carry a film. She holds the camera and it responds to her in kind. “A Star is Born” was not a fluke. She’s got an Oscar coming, but maybe not this time.