Take two Oscar winners, add the silliest screenplay in recent memory and you have a certified head scratcher.

If you’ve seen the trailer for “Serenity” you might think you know what to expect.

Not even close.

The term “bait and switch” rushes to mind. Then again, put yourself in the film’s marketing department shoes. How in God’s green earth could you package this clunker?

The bigger question? Is everyone involved serious?

“Serenity” packs a big ol’ mystery at its core. Until then, it’s almost like a parody of a watery film noir, complete with every hard-drinking, harder living cliche. You’ll laugh early and often, thanks to riotously corny dialogue and characters who can’t stop spouting exposition points.

Is that all on purpose, though? And why?

The film opens with our “hero,” fisher man Baker Dill (Matthew McConaughey), pulling a knife on a client.

Over the top? Of course, but it’s as hyperbolic as the score’s opening notes. That music rarely lets up, as if “Serenity” solved world peace mid-movie and composer Benjamin Wallfisch just couldn’t help himself.

We soon learn Dill is broke, both spiritually and financially. So he’s none too pleased to see his ex, Karen (Anne Hathaway) re-enter his life.

She’s got a new, rich husband (Jason Clarke of “Chappaquiddick” fame), but he spends his days beating and berating her. And not always in that order. Will Dill push the monster off his boat (named … wait for it … Serenity) and spare Karen a lifetime of pain?

Sounds like a garden variety potboiler with two beautiful Oscar winners at the helm, no?

Yes, and certainly no.

It’s darn near impossible to dig into “Serenity” without revealing too much. All is not what it appears, suffice to say. Getting to that reveal, however, is more than a chore. It’s an endurance test, assuming movies so bad they’re hilarious aren’t your thing.

McConaughey may be smokin’ and drinkin’ like an A-lister, but there’s a throwback element to his performance.

You guessed it. He’s in shirtless mode again, and there’s not a strip joint in sight.

Writer/director Steven Knight (screenwriter, “Burnt”) follows Dill, sans clothes, for an unconventional bath that doubles as a Skinemax audition reel. We even get a fast zoom move to make sure we can’t look away.

FAST FACT: Matthew McConaughey’s  J.K. Livin foundation aims to empower high school students to prepare them for the challenges ahead.

For a semblance of gender balance, the director trots out the same visual tic for Hathaway introduction. At this point you half expect Leslie Nielsen to appear in full “Naked Gun” character.

“What happened to Nordberg?”

The story gets sillier from there, with Clarke cast as the worst, uber-rich beau in screen history. He inspects his naked wife for minor imperfections and treats everyone he meets as if they should bow to his oversized wallet.

Talented actors like Diane Lane and Djimon Hounsou flesh out a cast far better than this story deserves. Lane’s appearance is baffling, but she aligns herself with the film’s signature metaphor. A wandering black cat works overtime here.

“Serenity” might have fared better as a half hour anthology episode. The kind where we don’t have to suffer through a protracted slog of a story before the big reveal. As is, “Serenity is an early Worst of the Year candidate.

HiT or Miss: “Serenity” plays like a film noir parody, but no one’s tongue is anywhere near their cheek.