Let it be stipulated that the movie “Serenity” is about a battered woman (Anne Hathaway) who is trying to persuade her ex-husband (Matthew McConaughey) to murder her current one (Jason Clarke). And let it also be stipulated that the movie “Serenity” is absolutely not about that.

At first glance, the film is a contemporary film noir so pulpy, steamy and — most regrettably — cheesy that it has all the appeal of microwaved nachos. The dialogue is bad, to the point of self-parody. The performances are cartoonish, especially that of Hathaway, whose femme fatale comes across as a kind of live-action Jessica Rabbit from “Who Framed Roger Rabbit.” And the scenario abounds with cliche and lazy shorthand: McConaughey’s Baker Dill — a traumatized war veteran and captain of a chartered fishing boat for wealthy tourists — drinks rum to excess from a mug labeled “World’s Greatest Dad.” That tells us that he has a child somewhere, and that their relationship is fraught.

On closer inspection, however, these defects reveal themselves not to be flaws of execution, but deliberate stylistic choices by writer-director Steven Knight (“Locke”). To use a term from computer programming, “Serenity’s” problems aren’t bugs — they’re features. Put another way, the entire story takes place inside invisible air quotes. It isn’t a bad movie. It’s a “bad” one.

Allow me to explain, to the extent that I can.

Any reviewer of “Serenity” is likely to struggle not to spoil its humongous plot twist. Like the earliest symptoms of the flu, it begins dropping hints of its existence from the get-go, but it only breaks out in full fever gradually, until it consumes the narrative.

The very first frame, in fact, tells you something is not quite kosher. Whose eye does “Serenity” open with, in close-up? Why are the characters all so caricatured? Baker has embarrassing sex scenes with a neighbor (Diane Lane) that play like the fantasies of a 13-year-old boy. Who is this business-suited nerd (Jeremy Strong) who keeps showing up, without explanation, tromping through the surf in his leather dress shoes? And why, if the story is set in the Caribbean, as it seems to be, is the island’s name, most improbably, Plymouth?

You will, no doubt, have a few head-scratchers of your own.

All will be revealed in the fullness of time — assuming you don’t get so annoyed that you walk out after 15 minutes and slip into a screening of, say, “If Beale Street Could Talk.” (If it could, it might say, “Don’t watch ‘Serenity.’ ”)

Allow me to make one further stipulation: The twist is, yes, audacious, even daring. It’s full of risk and defiance of expectation. So half a star for that. Steven Knight, you’ve got some nerve.

But none of those things mean that the movie works.

Do you see my conundrum? I can’t say why “Serenity” fails without ruining it. But then again, it also does that all on its own.

R. At area theaters. Contains coarse language throughout, sexual material and some bloody images. 103 minutes.