Most genre efforts move in such a straight line that there’s no room left for suspense or anything at stake. Brit indie director Ben Wheatley’s second feature, “Kill List,” which he co-wrote with his wife Amy Jump, never moves in a straight line. Wheatley’s film is certainly influenced by Quentin Tarantino and European horror films of the ’70s, but he admirably melds and bends genres into a uniquely effective and rather nutty package that ultimately goes off the handle. Whether you feel its changes in tone and genre are abrupt or seamless, preposterous or effective, “Kill List” definitely isn’t formulaic or dull. It’s the kind of film that benefits from going into it fresh, knowing nothing.

Unflinching from the first frame, a screaming match of a domestic argument breaks out between financially strapped married couple Jay (Neil Maskell) and Shel (MyAnna Buring). He’s a former Iraq War soldier, now a layabout from not working for eight months. She stays at home to take care of their 7-year-old son. After the two can’t even get through a dinner party without fighting while hosting Ray’s buddy Gal (Michael Smiley) and his new girlfriend Fiona (Emma Fryer), Gal offers Jay to take on a new hit job. That’s right, Jay and Gal are both hired guns, and it’s no secret to Shel. The two friends have a history of a botched job in Kiev, but this new gig is supposedly easier and short, their three-man kill list consisting of (but not limited to) a priest and librarian. Signing the contract in blood is the easiest part, as the job inevitably goes to hell and takes a toll on Jay’s sanity.

A vivid dysfunctional-marriage drama at the beginning, “Kill List” morphs into a grim crime-thriller that gets a bit repetitive and finally falls into a rabbit hole to reveal a dark horror film. The parts would seem incongruent with each other, but not until the crux of its story does it really hit a consistent stride, and that’s past the middle. Because of the omniscient camera allowing us to see things that Jay and Gal don’t, hints are dropped to where the film might lead. Still, the shocking blow of an ending is as gasp-inducing and sinister as the film it borrows from, and no, the name of said film will not be divulged.

If the pre-credit image of an etched cult symbol doesn’t give you a lingering chill, there’s some intensely brutal violence on display. One uncut scene of brutality, with a hammer being the weapon of choice, will either make you look away or unable to look away with desensitized fascination. Based on stripped-down dread alone, there’s a scene that’s full of it, a chase through a dark underground tunnel. The music by Jim Williams is jarring with an unnerving, foreboding vibe that simmers over the proceedings.

Credibly performed, the film gets natural performances out of Maskell and Buring as husband and wife, and ditto for Maskell and Smiley as close friends. Maskell’s Jay is introduced honestly and not made to be a likable protagonist, having a sadistic streak in him when it comes to getting each job done.

As bait-and-switch storytelling, “Kill List” starts as one thing and ends up another. And for that, it’s baffling, disturbing, and even a little bat-shit crazy. What does it all mean? Viewers can draw their own conclusions, but the reaction should be the same: it washes over you with the impact of an atomic bomb.

95 min., not rated.

“Kill List” is available on Video On Demand and iTunes, and in limited release.

Culture Disturbing, Baffling KILL LIST punches you in the gut