The late character actor turned director Bill Paxton once shared his secret to landing any directing gig with me.

“Tell ’em, ‘I can cut a HELLUVA trailer out of this!”

That’s what “Proud Mary” is, a helluva trailer with Taraji P. Henson as mistress of mayhem, mowing down mob minions to the strains of Tina Turner covering John Fogerty’s title tune. There’s little more to it than that trailer, a movie that expends its thin grasp of classic blacksploitation action pictures in an opening homage to the ’70s genre — graphics, music, colors and font introducing its version of “Foxy Brown” set to “Papa Was a Rolling Stone” — and a bravura finale that is basically the trailer that sold the picture in the first place.

No, Screen Gems didn’t screen it for critics and no, that’s not unusual for the studio that gave us “Underworld” and “Resident Evil” movies. It’s a classic “January film,” not worth promoting, something those who saw racial bias in abandoning the film to its fate seem ignorant of.  January is when weak sisters of a studio’s slate get dumped.

Not that this applies to Henson. The movie may meander and mope along, and tend toward maudlin sentimentality. There’s too much that’s familiar, too much that isn’t worth saying or doing that the characters say or do. There’s too much Maserati, a bit of flashy product placement meant to show how good hit-woman Mary (Henson) is at her job. There are maybe 25 shots of the car going here, going there, Mary peeling out, power sliding and what not to show her determination.

We meet Mary as she’s carrying out a hit. There’s a kid, wrapped in headphones, deep into a video game, in the same apartment. Mary has the same code as the hit-men of John Woo’s action films with Chow Yun Fat — “No kids.”

A year later, Danny (Jahi Di’Al, lo Winston) has become a tweenage drug mule, armed and delivering product to dealers and cash to his brute of a boss. Mary sees this, lets maternal guilt get the best of her and takes Danny in. She also takes care of a member of Boston’s Russian mob.

And when that threatens to start a mob war, she covers up the crime by murdering another lieutenant of her boss (Danny Glover), a guy whose cold-blooded assassination she and this three-legged script justify by calling “a perv.”

As the bodies pile up and the boss’s son (Billy Brown), who used to have a “thing” with Mary, she and the kid bond in some of the clunkiest exchanges of any action movie ever. At some point the kid (an unskilled actor who telegraphs every emotion by taking a big breath for his BIG closeup) curses, and Mary tells him “Watch your mouth.”

What they were going for here is “Atomic Blonde” (see above) meets the murderously maternal “Gloria,” and Henson just can’t make it work. Giving up its blackspoitation style too early, killing time with dimly-lit filler scenes in between killing sprees, fetishing firearms and Taraji’s makeup/lipstick rituals,, her boots, there’s little coherence to its style and subtexts even if its plot is penny plain.

The one teachable moment the mother figure has with the mouthy kid is “You stay ready you ain’t gotta GET ready.”

The best line is uttered by a guy gunned down in the first post-credits scene. “You shoot your mouth off like a parrot with t–s!”

And the best villain, McDonough, is dispatched with scarcely a thought.

Nothing much to be proud of here. Buy the soundtrack, skip the movie.

MPAA Rating: R for violence

Cast: Taraji P. Henson, Billy Brown, Danny Glover, Jahi Di’Al, lo Winston, Neal McDonough, Margaret Avery

Credits:Directed by Babak Najafi, script by John Stuart Newman, Christian Swegal, Steve Antin. A Screen Gems release.

Running time: 1:29