Spending two hours in a darkened theater

They only come out at night.

Dirtbags, lowlifes, predators — they’re just some of the dangerous beasts that “Nocturnal Animals” focuses on.

But there are other things that live in the dark, too: self-doubt, nagging regret, the sense that somehow, somewhere, things went wrong.

And those can be even scarier monsters.

“Nocturnal Animals” is directed by the fashion designer Tom Ford and it looks beautiful in a way that glossy ads are. Jake Gyllenhaal is hunky (and, as usual, briefly shirtless). Amy Adams is as pretty and perfect as a doll.

She’s just as cold, though. And so is the film.

Because this is a movie about all the ways we hurt each other. And although sometimes it’s through vicious violence, sometimes it’s in subtler, nastier, icier ways.

The idea is that Adams’ Susan and Gyllenhaal’s Edward were married once, a long time ago. He was a struggling novelist. She wanted a safer, softer life. They divorced, and she married some rich jerk.

And now Edward has a novel coming out, which he wants Susan to read. It’s a gruesome thriller about a too-nice guy who gets caught up in a carjacking, and sees his wife and child brutally abducted.

But why, after almost 20 years, did Edward send Susan this book? And why is it really dedicated to her?

Those are Susan’s first questions and they’ll be answered, eventually — although not in the way she wants.

But first we have to make our way through three interwoven stories — flashbacks of Susan and Edward’s life together, snapshots of Susan’s life now as she’s reading, and Edward’s book, acted out as a sort of movie-inside-the-movie, with rangy Michael Shannon as a Texas lawman.