Lucy in the Sky is not good, but it’s a little hard to pinpoint why. It’s based on the story of Lisa Nowak, the astronaut who, in 2007, drove from Houston to Orlando wearing a diaper, chased down the guy she had an extramarital affair with, and attempted to kidnap his new girlfriend. Sounds like it should make for a pretty good movie, right?

The diaper’s not in the movie, and Nowak here is called Lucy Cola; she’s played by Natalie Portman in a Dorothy Hamill bob and a stretchy Southern accent. Lucy drives to the San Diego airport, not Orlando’s, and there are other changes, too—rather than rehashing a tabloid scandal, Lucy in the Sky would rather use it as a jumping-off point to explore character and interiority. In the right hands, this would be a good sign for a smart movie.

And the hands seem to be right. Lucy’s directed by Noah Hawley, whose track record on television has some exceptional high notes (Fargo), and even his lower ones (Legion) are usually because of an excess of ambition—too many good ideas rather than a lack of them. Hawley’s a terrific writer and a remarkable visual stylist; his debut feature film should be something worth leaving the house for.

And yet. Lucy in the Sky is flat and cold and terribly dull, despite decent work from Portman and her co-stars, including Jon Hamm as her philandering astronaut flame, Dan Stevens as her steady-as-a-rock husband, Zazie Beetz as the other woman, and Ellen Burstyn as Lucy’s foul-mouthed, chain-smoking Nana. The opening sequence, with Lucy performing a spacewalk above a vast, unreal blue marble, is the movie’s high point, and it’s meant to be deliberately anticlimactic when Lucy comes tumbling back down to Earth and finds it wanting.

Part of the problem is that we know exactly what’s going to happen. We know she’s going to cheat on Stevens with Hamm, and we know she’s going to kinda lose it when Hamm gets with Beetz, and we know she’s going to put on a wig and get in a car and drive a very, very long distance in order to intercept them. Hawley’s interested in all the grace notes that happen along the way, which is fine—but this is quite a plot, and the main thrust of it here is totally dampened, which robs the movie of any sense of fun.

Nevertheless, there are some good storytelling ideas. Lucy has the hallmarks of what should be a terrific character—she’s a brilliant woman with plenty to prove, and she’s not just dealing with the relative disappointment of everyday life on Earth, she’s got the entire boys’ club of NASA to contend with. Hawley’s directorial eye is generally alluring, too, as he futzes with aspect ratios and color palettes to convey Lucy’s inner emotions.

But there are also some bad storytelling ideas, primarily in the form of the character of Lucy’s niece, who strangely accompanies her on the drive from Houston to San Diego. I don’t know if this niece is based on any real-life counterpart, but she's unwanted baggage—literally symbolic of the extra weight women have to carry around while men (e.g., Lucy’s deadbeat brother) avoid responsibility. It’s clunkily handled, and at odds with the nature of Stevens' husband character, a kind and selfless presence in Lucy's life. The addition of the niece to the mix is quietly baffling whenever it's not outright annoying.

Those good and bad storytelling ideas, taken together, don't amount up to much, and I think it’s because Hawley doesn’t interact with the entirety of the story itself. Instead he picks and chooses the themes he wants to play with and ignores the other stuff, creating a rigged game-board that suffocates any sense of drama. Hawley’s clearly enamored with Lucy, who seems to be more or less his own creation—but this comes the expense of the very real Nowak, a far more tragic and confounding person than Portman’s Lucy ever ends up becoming. Nowak’s actual story is the furthest thing from boring, but Lucy in the Sky is exactly that.