When it works, there’s a heedless, reckless energy to the desperation Vanessa Kirby brings to “Night Always Comes.”

As a sex worker whose unhappy home life led to a string of impulsive, life-threatening decisions, Lynette is racing against a deadline to raise the down payment for a house that won’t so much lift her prospects for the vanishing “American Dream” as allow her to cling to what little she has.

And when Lynette lurches into crimes, ill-considered “deals” and rash, in-the-moment miscalculations, director Benjamin Caron (“Sharper,” TV’s “The Crown”) finally achieves the pace this day-and-night ticking clock melodrama demands.

But the rest of the time, this dressed-down version of the “Mission: Impossible,” “Pieces of a Woman” and “The Crown” star is a case study in why “melodrama” is not something you want out of a film.

Contrived situations abound as Lynette reels from her mother’s (Jennifer Jason Leigh) spiteful decision to impulsively buy a car with the down payment money Lynette now needs to raise.

Lynette stumbles into a series of “stock” characters . A married “regular” (Randall Park), an old friend “in the life” (Julia Fox), a pawn broker who once “used” her (Michael Kelly), an ex-con co-worker (Stephan James) at one of her two jobs to an ex-con safecracker (Sean Martini) down to a sleazeball drug buyer (Eli Roth) all must be met, charmed or cheated in her mad pursuit of $25,000 in roughly 18 hours time.

Every encounter could get her closer to the cash or deeper in trouble. And lying, angling, finagling Lynette can’t help but insult or otherwise cross every single person she needs to do her bidding or supply the down payment.

Her mania to “save” her older special-needs brother (Zack Gottsagen) from “the system” (supervised care) is meant to explain everything. But this journey through one hellish night in Portland, Oregon is just one set-piece encounter/negotiation/confrontation after another, each one feeling more “scripted” than organic.

James, as Cody the guy she’s heard is an “ex-con,” is the most fully-rounded character among Lynette’s parade of “The Used.” But their repetitive, mistrustful and interogatory conversations between action beats stop the picture dead.

In Sarah Conradt’s script based on a Willy Vlautin novel, Cody went to jail for robbery.

“That’s not the whole story.” “”What’s the whole story?”

“I was set up.” “You were set up?”

“Yeah, that’s the WHOLE story.”

Kirby’s down-and-dirty look here doesn’t wholly obscure the famous eyebrows and cheekbones, and the picture rarely comes close to wallowing in what “the bottom” looks like, and that goes for her performance, too.

Lynette’s late-for-meetings/work excuses fibs and bigger lies, thefts and confrontational moments with those she “blames” for her plight occasionally feel lived-in or credible. She strikes one as somebody who has leaned on her looks for a lot in life, even a life this downmarket.

That’s why for all these shortcomings in the name of scripted expedience, this picture had possibilities. Breathless, ticking-clock pacing would have stripped the narrative of the many pauses where we’re allowed to think “Oh come ON” before the next stock character makes a bow, the next blow lands or next crooked angle presents itself.

Rating: R, violence, drugs, sexual situations and profanity

Cast: Vanessa Kirby, Stephan James, Zack Gottsagen, Randall Park, Julia Fox, Sean Martini, Eli Roth and Jennifer Jason Leigh.

Credits: Directed by Benjamin Caron, scripted by Sarah Conradt, based on a novel by Willy Vlautin. A Netflix release.

Running time: 1:52