Jeremy T. Thomas and Keri Russell in 'Antlers.'
CNN  — 

“Antlers” has a lot on its mind for a horror movie opening two days before Halloween, branching off in too many directions that never quite knit together. Produced by horror maestro Guillermo del Toro and directed by Scott Cooper (“Hostiles”), it starts out well enough but loses steam as the creepy outlines gradually come into shape.

Environmental activism, treatment of indigenous people, the opioid epidemic, and child abuse all figure into the story, which hinges on a middle-school teacher, Julia (Keri Russell), and her brother, the local sheriff (Jesse Plemons), reunited in the small Oregon town where they not-very-happily grew up.

Julia has noticed a student (Jeremy T. Thomas) who is exhibiting signs of trouble, and the picture doesn’t get any better as the audience peers into his home life, which includes having his dad and young brother locked away behind a bolted door, fearing what will happen should they somehow get out.

Aside from the message that it’s not wise to mess with Mother Nature, “Antlers” explores the possibility of real threats behind myths and legends, which is frequently fertile terrain. In this case, it’s the notion of something dark and evil lurking in the local mines, rooted in Native American folklore.

Adapted from the short story “The Quiet Boy” by Nick Antosca (who shares script credit with Cooper and C. Henry Chaisson), the movie has an unsettling quality in the early going that dissipates as more revelations slowly drip out. Yet all those aforementioned real-world references feel increasingly forced, as if reaching for relevance that isn’t really supported by the monster motif that eventually takes over.

As with Del Toro’s early features, a la “Pan’s Labyrinth,” the look and design prove elaborately grotesque, but by that point what appeared to begin with more elevated ambitions has seemingly settled for monster-movie cliches.

The net effect isn’t necessarily bad assuming that expectations are modest, and there’s something to be said for a more understated, small-scale approach to horror that doesn’t confuse body count with scares. Yet considering where the story starts, the place where “Antlers” winds up doesn’t leave much to hang one’s hat on.

“Antlers” premieres in US theaters on Oct. 29. It’s rated R.