My stars and garters, I cannot remember a generally thoughtful science fiction film going completely go off the rails in its finale the way “LX 2048” does.

What begins as a gloomy commentary on a world dialed-in and “tuning out” reality, a reality in which atmospheric damage and sunspots have rendered going outside in daylight toxic and the cost of people living “virtually” in human emotional terms, ends in a long, loopy scene that can only be described as clone camp.

And even that’s missing the one thing that camp cannot live without. It’s not funny.

James D’Arcy (“Dunkirk”) stars as Adam Bird, a highly-strung VR firm vendor/planner/consultant who disconnects from the goggles everybody lives behind to visit his doctors in “daylight hours” and actually show up at staff meetings in the company conference room.

No one else bothers to come. They’re all there virtually. So all his shouting is via VR goggles. All his dire warnings that their pricey specialty business, providing the gear that gives people access to “The Realm,” and its “real buddies (friends)” and avatar lovers is about to become obsolete because “chip” is coming, promising everybody implanted instant access and thus instant escape, and providing that service much cheaper.

Adam is raging against the machine, and against public compliance. But his doctor (Gina McKee) has bad news. His heart’s giving out. This insurance policy “Premium 3” promises that he’ll be replaced by a clone, who’ll continue supporting his estranged wife (Anna Brewster) and three kids. But what’s that do for Adam?

He’ll track down this genius scientist (Delroy Lindo) who might be able to give him some answers. Donald Stein shows up with a pistol, crazy eyes and a dark vision of the world they’re in and how its promise may have missed a few things — “instinct,” “compassion,” a soul, etc.

As Adam’s virtual lover Mia (Gabrielle Cassi) puts it, her “five senses” test out fine. She just can’t “feel.”

Writer-director Guy Moshe (“Bunraku”) sets all this up well enough. Sure, the scientist introduction is comically abrupt, but Lindo’s Donald Stein is convincing at getting across the “existential dread” of our current (future) times, all while being Delroy Lindo cool.

Wait, you can smoke? How? (Must’ve been banned.).

“I’ve got a guy who’s got a guy.”

D’Arcy slings an American accent and does quite a bit of shouting here. You’d think the guy was dying, running out of time, too impatient to worry about hurting the feelings of clone-doctors.

“I just can’t relate you people…your kind.”

Brewster, of TV’s “Versailles,” gives a performance of eccentric, theatrically metallic line-readings — not just an angry ex-wife, but one down the digital rabbit hole of “The Realm” so deep that she sounds like a clone.

The picture’s got a vivid vision of the future — vivid on a budget. Adam’s defiance includes driving his Mercedes with the top down — in his haz-mat suit. Everybody else gets around via elevated pneumatic tube-trains. When they bother to go out at all.

This “virtual” instead of “real” world, with its toxic environment and compliant, drugged and plugged-in populace, feels insanely topical at times.

But damned if “LX 2048” doesn’t go completely crackers at the end, with D’Arcy there as both eager participant and appalled eyewitness.

MPAA Rating: unrated, violence, some nudity, sex, profanity, alcohol, smoking

Cast: James D’Arcy, Anna Brewster, Gina McKee, Juliet Aubrey, Gabrielle Cassi and Delroy Lindo

Credits: Written and directed by Guy Moshe. A Quiver release.

Running time: 1:42