We’re still in Kansas, Dorothy. But with “Brightburn,” we’re not in Smallville any more.

It’s a twisted take on the “Superman” origin myth, an alien baby adopted by humans in rural America, raised on “wholesome rural values,” and yet when puberty hits, he’s a monster, not an icon of “Truth, Justice and the American Way.”

How’d this happen?

OK, his parents, the Breyers (Elizabeth Banks and David Denman) swear. A lot. And Dad hits the local bar. But Mom is full of reassurances that “You’ll always be my baby boy.” Can she turn him around once all this omnipotent power has gone straight to his 12-year-old head?

It’s a Screen Gems movie. What do you think?

If Screen Gems was ever going to do the “Evil Superman” picture, it was always going to be a horror film. And yeah, it was going to be cut-rate.

“Brightburn” is a blood-spattered wallow in extra-terrestrial cruelty, a child who has it pretty good discovering he dropped to Earth in a spaceship, and thus is even more “special” than he thought. That moment he figures out his super-strength, that he can’t hurt his hand in the running lawnmower he’s just tossed two football fields away, little Brandon Breyer (Jackson A. Dunn) has his mission.

“Take the Earth.”

Brightburn, Kansas? Well a boy’s got to start somewhere.

There are parables aplenty just dangling here — low-hanging fruit for screenwriter/brothers Mark and Brian Gunn, not the only Gunns in the movie-writing business, but certainly the ones with the least to offer (“Journey 2” was their big credit).

They do nothing with the notion of entitled, indulged kids, or ADHD kids, or rural Red State values imprinted on a new Superman, who brings down destruction upon us all, or great power handed to the worst possible character to wield it.

That’s all here, but not developed.

All we’re given is instance after instance of unspeakable, gruesomely-detailed cruelty — drawn out small town murders carried out by a boy whose initials match those of his town and obsess him; a boy who can fly, shoot laser beams out of his eyes and who has no compunction about using those powers to answer every slight or perceived slight.

I guess we’re lucky he doesn’t tweet.

“Brightburn” is a generally humorless affair, with the only “laughs” given a sadistic edge, with paint-by-numbers frights and cut-and-paste “big emotional moments” that even the formidable Banks cannot make pay off.

Another horror movie about a soul-dead child who excuses monstrous behavior with “Sometimes bad things happen to people for a good reason” is nothing to to buy a ticket for.

The scares are built out of how fast the little Dickens is, the creepy mask and cape getup he comes up with, the “powers” he has. But editor-turned-director David Yarovesky doesn’t give them any juice, and can’t be bothered to make more than one of them a surprise.

It’s not hatefully bad, just inert. Botched. Dull. Pointless.

MPAA Rating: R for horror violence/bloody images, and language.

Cast: Elizabeth Banks,  David Denman, Jackson A. Dunn, Emmie Hunter and Gregory Alan Williams

Credits: Directed by David Yarovesky, script by  Brian Gunn, Mark Gunn. A Sony/Screen Gems release.

Running time: 1:31