What more can be done with the “Ten Little Indians” formula — packing people into a “trapped” scenario, and picking them off, one-by-one?

“The Belko Experiment” proves that the answer is “nothing,” if you don’t count “We can always make it more gory/graphic.” It’s a depraved disappointment, considering those involved.

The plot, invented by Poe and perfected by Agatha Christie, hurls disparate characters into a desperate situation, and lets them show their true colors as each is slaughtered in turn.

Belko Industries is a multi-national recruiting non-profit (?) set up in a gigantic, remote high-rise in suburban Bogota, Colombia. One day Michael (John Gallagher, Jr.), the boss (Tony Goldwyn) and everybody else drives onto the property to find armed uniformed soldiers checking everybody in.

Not everybody. Just the foreigners. The locals are sent home.

Eighty folks — from creepy managers (John C. McGinley) to grunt maintenance engineers (Michael Rooker) and new employees (Melonie Diaz) — are in the building when the PA system alarms everyone.

They are ordered to “murder any two of your fellow employees,” or else. And before the shock is shaken off, metal shutters slam down over every exit, the clock “expires” and several of their number die — their heads exploding.

Must be that “tracker” the company implanted in their necks, reasons Michael. He freaks out, which his office romance (Adria Arjona) finds unmanly and his boss uncalled for.

“I don’t believe there’s any cause for panic,” he says. Not that anyone believes him.

They’re given a couple of hours to pile up 30 bodies, and that’s time enough for the factions to form. Murderous management is out for itself, office drones try not to become their prey, the competent engineer wanders off in search of solutions and the stoners, led by Marty (Sean Gunn) head up to the roof to light a “j” and cope.

James Gunn, Sean’s brother, gave us “Guardians of the Galaxy,” and his script has Michael as the voice of humanity and reason. Even if they do what the  PA “voice” orders, they’re doomed (no witnesses will be allowed to escape). Why kill each other?

Not that anybody else listens.

Goldwyn is reliably venal and self-serving (think back to his “Ghost” villainy),  McGinley properly unhinged.

The trouble is, nobody else engenders sympathy or registers. They’re just victims waiting to happen. And once you’ve seen one head explode, you’ve seen enough. Ugh.

Too little is made of the workplace satire that was this story’s selling point. Anybody who works for a living in America knows “corporate” would just as soon kill them, if it helps the bottom line. There are no heroic “undercover” bosses — just automatons looking to get theirs, at your expense if need-be.

“Wolf Creek” director Greg McLean efficiently runs through the deaths, but where’s the terror, puzzle-solving logic or anything else to hold our interest? It’s just unpleasant, nothing more.

And there’s this pet peeve I have about any movie with people “trapped” and doomed,  unable to call for help. From “Don’t Breathe” to “Belko,” they never figure out the obvious.

Set a fire.

MPAA Rating: R for strong bloody violence throughout, language including sexual references, and some drug use

Cast: John Gallagher, Jr., Tony Goldwyn, Adria Arjona, John C. McGinley, Melonie Diaz, Michael Rooker

Credits:Directed by Greg McLean, script by James Gunn. A Blumhouse/Orion release.

Running time: 1:28