An outstanding cast and an artificially upbeat ending had some Sundancers soiling their Underoos over “Fast Color” in snowy Utah some four winters back. And that finale had just enough wriggle room to tempt Amazon into putting a series based on the film into pre-production.

One suspects that it wasn’t just a pandemic, but saner heads prevailing, that stalled that Amazon adaptation. It’s not that a female African-American superheroine tale couldn’t work, or that the wondrous Gugu Mbatha-Raw or “Belle,” TV’s “Loki,” and “The Morning Show” couldn’t carry it. It’s that perhaps no one could get this dead weight across the finish line.

Director and co-writer Julia Hart of “Miss Stevens,” “I’m Your Woman” and Disney TV’s “Star Girl” serves up a fine dystopia and three generations of supernatural women “trying to get by” as End Times take civilization down the drain. But Hart is so sparing with her action beats and so staid and self-serious in her supernatural touches that the picture never sparks to life.

This version of the climate crisis endgame captures a rural America desultorily going through the motions as years and years pass without rain. Drinkable liquid is dearly bought and highly-priced.

Ruth (Mbatha-Raw) is on the lam, a somewhat tortured soul making her way from cash-only motel to not-yet-dry bar, haunted and hunted.

A “seizure” she feels coming on explains half of that. Something in her makes her cause earthquakes. And that “friendly” stranger (Christopher Denham) at the diner where she finishes the lone fried egg she can afford might not be so friendly.

“Where you headed?” “Oh, I’m just going.” “What does THAT mean?”

Even his “rescue” when Johnny Law shows up looking for her has strings attached.

“I’m a government scientist…We just want to run some...tests.“

Elsewhere, a little girl (Saniyya Sidney) tinkers with electronics and fixing a pickup truck, listening to the stories and guidance of her grandmother ( Lorraine Toussaint of “The Equalizer” and “Orange is the New Black”) Bo.

There’s something mysterious about these two, their shared “powers.” Seeing the “colors” is a sign that they’re able to atomize objects as they see fit, even though putting things back together again is an iffier proposition.

“If something’s broken, it stays broken,” Bo intones, laying our big societal/environmental metaphor out for all to see.

Ruth of course is the little girl’s mother, Bo’s daughter. And her homecoming is fraught, with those “scientists” and assorted cops looking for her, cops including a sheriff (David Strathairn) whose pleas for “some semblance of order” seem as despairing as everything else about this desertified landscape.

After a promising start, “Fast Color” comes to a dead stop in its ponderous, exposition-packed middle acts. Toussaint and Mbatha-Raw bring plenty of gravitas to their explanations of their gift, its coming and going nature and their fractured family history, all provided more for the benefit of the child than the viewer.

Hart never gives her film a sense of urgency, which may suit the funereal “We’ve all given up” tone, but it sucks away what little life there is to “Fast Color” the moment Ruth finds her way “home.” A good rule for screenwriters, “the quest narrative is your friend. Abandon it (‘get there’ too soon) at your peril.”

Denham is only modestly effective as the villain of the piece. The effects are equally modest, a tad underwhelming.

As is every one of the later scenes leading up to the unearned Big Finish, which the only thing that really explains this picture’s “Sundance Moment.” As for the series to be based on it? That faint “whooshing” in the background is the air going out of that balloon.

Rating: PG-13 for a scene of violence and brief strong language

Cast: Gugu Mbatha-Raw, Lorraine Toussaint, Saniyya Sidney, Christopher Denham and David Strathairn

Credits: Directed by Julia Hart, scripted by Julia Hart and Jordan Horowitz. A Lionsgate release on Netflix, Youtube, Hulu, Amazon etc.

Running time: 1:40