Neil Marshall's Centurion is by far his most serious movie, though that's not saying too much. The bleak, snowy hills of Scotland are the setting for a slicey, dicey Roman invasion against the dashing, plucky Celtic tribes. The Romans are tired! These Celts just refuse to be slaughtered!

It's a proper historical epic, set just a few generations after Christ, but with massive splatter effects, back-stabbing, hostage-taking, giant fiery rockballs obliterating legions, good witches, and hot mute lady-warriors with complicated hair—why, this movie has it all. (It is also slightly difficult to follow, because everyone looks equally unwashed, but no matter. The joy is in letting it wash over you!)

“Even Raiders had people on spikes and melting people. A guy going into a propeller! The horror is underlying that.”

So, yes, by serious, we do mean somewhat camp—in a good way! How camp? Well, it's got everyone's favorite detective from The Wire, Dominic West, who plays Titus Flavius Virilus, the hot Roman commander. Hubba hubba!

The joy of Neil Marshall films is that he does not take himself so seriously. (His last film, Doomsday, had an extended scene in which a man was barbecued to the sounds of Siouxsie and the Banshees, with post-apocalyptic savages waving plates and forks.)

It's an exceedingly refreshing take on filmmaking. He wants to make you laugh and go "ooh" and go "eww." And while Neil Marshall is usually thought of as a horror director, he dearly wants to be considered an action director, which makes his films make a bit more sense.

Oddly though, he mostly makes films about walls. In The Descent, his best-regarded and most-terrifying film, the cast—all women, by the way—spends most of the film crawling through horrid tight spots in caves. In his next and most wonderfully outlandish, Doomsday—yes, with the cannibals, so think Mad Max meets Aeon Flux—Scotland is walled-off due to a viral emergency. And Centurion, which opened this weekend, is set somewhere between the inception of Hadrian's Wall and before the building the Antonine Wall.

This also means that Marshall, a nice boy from Newcastle who is now just 40, has already covered humanity's past, the present, and a possible future—and found them all terrible. "It's a dark and bloody place," he says of the world, shrugging this idea off.

No, but really. The body count of the cast in The Descent approaches a full 100 percent. The body count in Doomsday hovers around 5,194,000 people, given that he kills off the vast majority of Scotland in the first 10 minutes. And in Centurion, there's an uncountable number of throats gushily slashed—an impressive percentage of the world's population, really, given that there were only roughly 200 million people on the earth at the time.

All this wanton blood-spouting and human-cooking and evisceration is apparently accidental, however!

"I'd like to be at the moment seen as an action director," says Marshall. "I've done four films, two are horror movies. I guess I'm an action director. My dream movie is, well, it's a project I have, this World War II-set action-adventure movie, which is more akin to an Indiana Jones thing. The movie I always say made me want to make movies is Raiders of the Lost Ark. That's my defining movie. That would be surrounded by a bunch of horror movies and other stuff. A good hero, good action—even Raiders had people on spikes and melting people. A guy going into a propeller! The horror is underlying that."

What Raiders has in common with Marshall's films is that it was also cheap. Raiders cost about $18 million in 1981—you can double that and add a bit more to account for inflation. Centurion cost, in today's dollars, something like $12 million. ( Doomsday, by far his most expensive to date, cost about $26 million. The Descent, by the way, which cost almost nothing, made nearly $60 million worldwide.)

But it doesn't mean he's making the movies he truly wants to make yet.

All this tromping around on the cheap and pushing small budgets gets exhausting. Turning 40 was a kick in the neck. "It was kind of a wakeup call! I've been behaving and thinking like a 20 year old for 20 years," he says. "It was weird! It was the first time I've been bothered about a birthday. I've never cared that much that I was going through my thirties. Suddenly I realized I better get some work done."

But what to do? Marshall is smart and quick to abandon projects when the money doesn't come through or when the genre mined seems tired. For instance, there was a time when fans were excited about Outpost, a film best summed up as "Zombies on an Oil Rig."

"The current status of Outpost is there is no current status of Outpost," he says. "It's a dead project. When I came up with the idea, no one was making zombie movies. It seemed fresh and original, and now everyone's making zombie movies. The market's completely flooded. So there's no need to make it anymore. We'll let that one go."

But, but, but, well then, what about vampires?

"No vampires!" he says. "I'm not that interested in vampires as a whole. To coin a phrase, it's been done to death. It's a huge thing—I applaud any filmmaker who brings anything new to the genre."

So instead he is working, with legend Sam Raimi as a producer, on something called Burst 3-D. The title is very telling. For instance, it will be in 3-D! And people will burst. Because all anyone has known for some time about the film is that it concerns "a group of people trapped in a winter lodge who suddenly begin to spontaneously combust."

So this is a dreamy plan, maybe, for the devoted horror enthusiast—but maybe not yet a fulfillment of an action director's dream. Why more splatter? Is he just a terrible sick person?

"I adore puppies. In real life I'm just a big teddy bear," he says. "It all lurks beneath the surface."

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Choire Sicha is co-proprietor of The Awl and is at work on a nonfiction book for HarperStudio.