For a director with the best horror film of the past decade under his belt (The Descent), it’s been hard to get a handle on Neil Marshall, what with his triumph being bookended by the slight-but-fun Dog Soldiers and, more recently, the fan-wank loveletter to 80’s B-movies Doomsday, an undisciplined mess of a film almost saved by sheer exuberance. (To lift a line from Pauline Kael, it was crap, but crap on a rocket-cycle.)

Happily, Marshall’s latest, Centurion (playing Friday night at The Neptune), manages to split the difference between his earlier films, resulting in a taut, suspenseful war film that can also go deliriously excessive when warranted. For anyone burned out on the quick-cut, overly stylized Bruckheimerization of modern action movies, this is the real head-banging deal.

Set during the early AD Roman conquest of Britain, Marshall’s script follows a dwindling cadre of Roman Soldiers (including Michael Fassbender and a scene-stealing Dominic West) struggling to get out from behind enemy lines while under constant siege from a rolling boil of ticked off Picts, led by a mystical, mute female tracker with one helluva grudge. Wolves are involved.

On the surface, this saga of desperate men against impossible odds may resemble 300, but Marshall eschews that film’s simonized, posturing stance in favor of a leaner genre sensibility: Characterizations are quickly sketched but satisfying, the bad guys are given just enough depth to be scary, and you always have a sense of who happens to be firing arrows at whom. The squeamish may want to look elsewhere (the filmmaker tends to have an issue with eyeballs staying in their proper place), but if you're in the mood for a guilt-free rush, this is just the thing: An all-out action film that won’t leave the viewer feeling ill-used. Fans of Gonad Cinema, hark.