In French, fourche means fork — so when I tell you right off that Curtis LaForche (Michael Shannon) isn’t sure whether his nightmares and hallucinations are prophetic visions or symptoms of madness, you too might think immediately that his slightly Americanized name indicates that this film is essentially an “is he or isn’t he?” story. But don’t make the mistake of thinking that’s all there is. This movie is scary as shit, as tight as a drum, and is the best portrayal of modern manliness I’ve seen since Fight Club (1999).

Other movies are scary because they portray terrifying scenes or build suspense till it’s nearly unbearable. This movie scares you because this is about your fears:

that your life, like Curtis’s, is a house of cards.

The job keeps food on the table and the mortgage paid. But that small list of accomplishments — like, you paid off the car — all fly out the window if you lose the job.

What will you do for health insurance, especially now that you’ve finally gotten approval from the insurance company to pay for your deaf daughter’s cochlear implant operation?

What if you lose your job and your insurance because you’re losing your mind?

“You have a good life,” his friend Dewart (Shea Whigham) tells him early on. It’s just about the best compliment a man can give another man.

But a good life is still just a house of cards. And the nightmares might be that gust of wind to knock it down.

In his dreams, the storm clouds build. Those first drops of rain are viscous and discolored, like fresh motor oil.

This isn’t a regular storm. It’s massive. There’s a funnel cloud.

These aren’t regular dreams. Sometimes in the dreams he gets hurt, and the pain lingers all day.

Of course he doesn’t tell anyone. He does what a good man does: he says, “It’s fine,” and shuts up. He goes to the public library and checks out a book called Understanding Mental Illness, which he studies in secret. He tells his doctor he’d like to see a counselor.

He’s going to take care of this, and no one needs to worry.

He visits his mother, who’s been institutionalized and heavily medicated for schizophrenia for the past thirty years, since he was a kid. He wants to know if these dreams are somehow genetic.

When she asks if he’s all right, he tells her he’s fine.

Then he takes a look at that storm shelter in the back yard, and everything in his very soul tells him that this is the solution. He knows he needs a bigger space if all three of them are going to be down there. Dewart will help, and won’t ask.

He weighs the options and figures out how to pay for it. He borrows some pretty serious equipment from work. He chooses a day when Samantha takes Hannah with her to the craft fair.

Here’s what you notice after a while: as the dreams get worse, Curtis’s eyes seem to get bigger, wider, more haunted. His mouth gets smaller as he keeps trying to swallow all his fears and exert, through sheer force of will, some level of control.

He can barely open his mouth, because what will he say if he does? Talking will make it real.

Except that sometimes they’re not dreams but waking nightmares. Hallucinations, the book on mental illness calls them.

One night driving home he has to stop the car. Hannah and Sam are asleep in the back, but he gets out to watch that huge electrical storm. Even here in the flattest part of Ohio, this storm is crazy. “Is anybody else seeing this?” he asks, and looks around with surprise to find no one else there.

And with that question, we know he’s opened up a can of worms.

See this film — and on the big screen if you can, because those wide, flat Ohio landscapes must be seen on the big screen. See it because Michael Shannon inhabits this role like no other living actor could — just seeing his posture in his work shirt and a pair of jeans reminds you of every blue-collar man in your family, and it helps you understand them like you’ve never understood before. (Would it even be fair to compare him in this role to other performances this year? Is the Oscar locked up so early?) See it because the film is trying to tell us something about where we are. And it’s also telling us things I don’t quite understand. When you do, we’ll have a conversation about that ending.

Holy crap, people. Take Shelter.