The Devil is in the details, the old saying goes. And that applies to movies as well as the plans we make in life, and how we execute them.

“The Monster” is sort of a Son (actually Daughter) of Babadook, a mother and child vs. beast thriller that never ratchets up much in the way of tension or suspense, a monster movie whose frights wash away in the rainy night once we see the guy in the rubber suit with big teeth.

Mom (Zoe Kazan of “Ruby Sparks”) is a wreck, an alcoholic whose tweenage daughter Lizzy (Ella Ballantine) is the one who cleans up the vomit and picks up the bottles after every beer bust.

Lizzy is young enough to still have nursery-rhyme singing dolls, to still be into TV cartoons. But she’s kind of the adult now that her dad (Scott Speedman) has checked out. She and her mother exchange curses and “I hate yous” at every turn, and Mom, when we meet her, has had enough.

She’s delivering Lizzy to her dad. But they hit something in the road — “I think it’s a wolf.” And even though they’re wrecked under street lights and there’s plenty of cell service, with a wrecker and an ambulance on the way, they’re going to be stuck in that car until the boogeyman comes out of the shadows — until we’ve seen the hell of their lives together in a series of flashbacks.

“The ambulance will be here soon!”

Mother and child are slow to awaken to the danger, stepping out into the rain, sticking their noses past the edge of the woods, putting their hands on the wolf corpse long enough to see that something was in the process of eating it when they hit it. A giant tooth was left behind.  That always happens.

When awful things start to pile up, Kazan manages to feign a little abject terror. Ballantine? A little less so. Maybe she’s seen the “Star Trek” episode where the Gorn suit that this beast resembles is featured — kind of a mini-Godzilla, all teeth and glistening skin and scary eyes.

Writer-director Bryan Bertino was onto something with the whole hate-filled mother-daughter dynamic. Its a brutal relationship that hits a lot of wince-worthy notes.

But “The Monster” is a slow-moving clunker of a thriller, with the pace so funereal you have time to wonder “This isn’t that remote. Why isn’t there a cop/tow truck/ambulance here already?”

The Australian thriller “The Babadook,” the most apt comparison here, hides its beast and assaults the viewer several times in its much-faster-paced 93 minutes.

“The Monster” is as dull and predictable as its title, a creature feature in which the melodramatic flashbacks are the only bits with bite.

MPAA Rating: R for language and some violence/terror

Cast: Zoe Kazan, Ella Ballentine, Scott Speedman

Credits:Written and directed by Bryan Bertino. An A24 release.

Running time: 1:31