Starring Michael Smiley and Reece Shearsmith. Rated 14A.

Showing up a good 20 minutes into this inspired headfuck of a movie, actor Michael Smiley reminds us that there’s a thin membrane indeed between comedy—the actor’s usual profession—and the kind of seething hostility that lays waste to everything. He’s a monstrous presence as O’Neil, an absolute bastard of an alchemist in this, the fourth feature from British filmmaker Ben Wheatley (working again from a superlative script by partner Amy Jump).

Four recently met deserters from the English Civil War are put to work looking for buried treasure by the heartless magician when they stumble upon O’Neil in that titular field—or rather, when they apparently pull him out of the ground with a rope.

Many other moments throughout the film similarly confound sense, especially after O’Neil forces (and I mean forces) his hapless crew to consume magic mushrooms. Death becomes mutable, time loops on itself, and what’s with that terrifying black sphere that seems to be consuming the entire sky?

Our sympathies and O’Neil’s true agenda both reside with Whitehead (Reece Shearsmith), himself an alchemist’s assistant sent, conveniently enough, to find and apprehend the other man. O’Neil makes short work of the junior necromancer, taking possession of his mind in one of the film’s more poetically disturbing scenes.

Whitehead’s new friends, meanwhile—including a particularly thick optimist named “Friend”—are no more trustworthy than anyone else in this darkly magical world.

The sum of all this is malevolent pastoral psychedelia, shot in black-and-white and delivered in cod 17th-century English, with a self-consuming narrative and moments of intense gore (plus an extreme close-up of something unspeakable growing on one character’s penis). How could it be anything but a classic?