Inside the mind it is dark. You imagine it is safe. You take refuge there. Outside of the mind is the world. The world is sick, dangerous.
You have a door between the two. You keep it locked. You have a protocol for the door to keep what is out, out. The people you trust, that you let inside, you expect them to keep to the protocol as well.
But at night something comes the door can't defend against. At night the dreams come, because the dreams live inside, with you. Dreams of doubt and fear. It's at night when the door is most necessary... and most likely to be compromised.
"It Comes at Night" shrugs off traditional horror beats and embraces the extended discourse of a nightmare, the inky blacks lit only by a hand-held lantern, the invisible contagions that we can't keep out no matter how hard we try, the way a fire we must light attracts things that might do us harm.
It's "Night of the Living Dead" without zombies. It's "The Thing" without a monster. It's the distrust we have of everything outside, even the outsiders that are inside. It's the long narrow dark hallway to a door that's supposed to be locked, must be locked, but isn't.
And it's one of the very best horror films of the year so far. A year that has already been a landmark one for progressive, humanist, and existential horror.
And yes, it is a horror film, no matter what others may tell you.