The hard part about making movies these days is all to do with special effects. The makers of “Severance” have made an entire second film, an eight-minute documentary called “Crashing a Coach,” especially for the DVD edition of Christopher Smith’s new movie to show how they filmed the coolest moment in “Severance,” when a bus flips rather spectacularly and slides a long way on its side.

I haven’t seen the documentary, but I’m prepared to believe that filming a bus crash is an immensely difficult and complicated exercise. I can testify that the end result is a visual treat for crash connoisseurs. Yet I can’t help wishing that a fraction of the thought and planning and energy that went into that scene had been spent on the movie’s plot.

But then that’s postmodern moviemaking for you. Not only do filmmakers not have to care about plot, they rather enjoy teasing the audience about how they don’t have to care about it.

Here’s the situation in “Severance.” Several employees of a British arms manufacturer called Palisade are on a bus to a rustic lodge somewhere in Hungary or the Balkans — there is also a tease about where they are — for a “team-building weekend.” Shadowy figures in the forest start bumping them off one by one.

Who are the killers and why are they doing this? Not only does the film refuse to tell us, it glories in its own ignorance — or, to put it another way, in the motivelessness of its murders. It does this by providing three different explanations for the killings, each more preposterous than the last.

Harris (Toby Stephens) tells us that the lodge had been an insane asylum before World War I. After the inmates staged a mutiny, they had all been gassed with the help of a Palisade-produced airborne toxin. Or all but one. Since then, the escapee (and, presumably, his heirs) has vowed vengeance against Palisade and all its employees.

Maggie (Laura Harris) claims that the lodge is the site where Warsaw Pact soldiers who were a little too fond of killing had been sent after the breakup of the Soviet Union. They too had been nearly — but not quite — wiped out by their own governments using Palisade-supplied weapons.

Steve (Danny Dyer) offers a third explanation, namely that the place had been an old-folks home where all the pretty young nurses had become frustrated into lesbianism by the lack of any virile young men — until someone looking a lot like Steve came along.

The joke of his offering an explanation that doesn’t even attempt to explain anything is an echo of the movie’s own jokey refusal to make sense in realistic terms.

To Mr. Smith, who directed and co-wrote the screenplay with James Moran, “Severance” is about picturesque slashing and chopping and burning and stabbing, and the black comedy he is able to wring from these various methods of violent death. The question of why any of it is happening doesn’t interest him. He evidently thinks it shouldn’t interest us either, which is why he ridicules the very idea of plot and motivation.

Well, fair enough, you might say. Except that the movie also has ambitions as a satire. You can tell by (among other things) its allusions to Cold War classics such as “Dr Strangelove” and the earliest James Bond films. It’s as if Mr. Smith wants to tell us that the threat of superpower-communism may have given way to the threat from freelance international terrorism, but really, nothing has changed. It’s all just a mad and dangerous world where nothing makes any sense.

The problem is that we know this is untrue. There is no mystery at all about the motivation of the terrorists who threaten us. To deliberately close your eyes to this by treating the killer or killers in the woods as wild beasts who kill for killing’s sake suggests that, like so many postmodern products, this is a movie not about the world we live in but just about other movies.

Cinema’s take on war and armed struggle as senseless and irrational violence has been carefully cultivated for more than 40 years, at least since the first of Sergio Leone’s spaghetti westerns and “Dr. Strangelove” came out at almost the same time, in 1963–64. The idea was commonplace by the time Francis Ford Coppola made “Apocalypse Now” in 1979, and it has remained so ever since.

If you find compelling the idea of yet another redaction of the same (false) idea — spiced up with a couple of scantily clad Serbian hotties with automatic weapons and a bus crash — then you might like this movie. But in spite of a few laughs and some witty dialogue, I found it a crashing bore.

jbowman@nysun.com