A high end housing development is going up on a big British farm that changed hands under unsavory circumstances, a development resented by locals, including the family that lost that farm, and all on ancient land with Druid legends attached to it.

There’s a star sculptress whose work is so prized the fact that she’s creating Druid monoliths to decorate each McMansion’s entrance is a huge selling point. She and her unemployed filmmaker husband are thus presented with the first finished home.

And on this night, the hustler-developer, his lady fair and the latest designer drug are guests for a dinner celebration.

Things are sure to get interesting as “alpha male” posturing, old resentments, broken promises and a toxic personalities are thrown together. And all that’s before masked intruders, the “real” “Barbarians,” show up.

The writing-directing debut of producer Charles Dorfman (“The Lost Daughter,” “The Honest Thief”) lurches from tetchy to tense to downright harrowing as two couples/four people spend the first and much of second act showing us how they really think of each other, only to be brutally tested by the goons who crash their party.

They’re mostly Brits. Can they learn the concept of “United we stand, divided we might not survive the night?”

Catalina Sandino Moreno (“Maria Full of Grace” and TV’s “The Affair”) is Eva, the confident sculptress who figures this new house and and between-projects filmmaker Adam (Iwan Rheon of “Game of Thrones””) is a “fresh start”for them. Bitter, jealous Adam may not agree.

Because tall, swaggering, showboating developer Lucas (Tom Cullen of “Knightfall”) is a bully and a blowhard and isn’t likely to let them — or Adam — forget what he figures they owe him. Whatever else Tom’s wife Chloe (Inès Spiridonov) might be, “enabler” seems to top her list of obligations.

Their evening is already on tipsy tenterhooks when Lucas trots out an eyedrop that promises to be “like ten years of therapy in one night.” And then comes that knock on the door and you-know-what gets real.

Dorfman and his players handle the long, nerve-fraying build-up with skill. And the payoff, with its twists, escalating violence and pointed causes-and-effects, doesn’t disappoint even if it’s a tad thin on surprises.

There are scores of home invasion thrillers that “Barbarians” borrows from — “The Strangers” and the French film “Them” seem most directly related to it. Wrapped in the trappings of horror, this formula action picture doesn’t get by so much on frights as on visceral trapped-and-trying-to-escape situations, which pay off nicely.

And as the violence escalates and whatever was getting out of hand gets seriously out of hand, “Barbarians” can turn downright riveting.

Rating: unrated, violence, drug abuse, profanity

Cast: Catalina Sandino Moreno, Iwan Rheon, Tom Cullen, Inès Spiridonov

Credits: Scripted and directed by Charles Dorfman. An IFC release.

Running time: 1:29