A Western-horror hybrid about a lapsed-faith missionary infiltrating an island cult to save his sister in 1905 doesn’t much sound like the forté for writer-director Gareth Evans.

Evans’ Raid films were unadulterated, fist-pumping triumphs of relentless, bone-crushing martial-arts action. Apostle exhibits far more patience before popping off its own powder keg of gore and violence. Its parable about religion’s perpetual shift from penitence to punishment perhaps doesn’t need 130 minutes to play out, especially with a protagonist who is literally a doubting Thomas. And the combat, however confidently captured, arrives like a make-good concession to early VVitch-like dread — Wicker Man turned Kicker Man.

At the same time, Apostle maintains the “undercover cop” structure of the Raid films while understanding that cult fervor connotes a fighting stance and frenetic energy all its own. It’s a film with plentiful pleasures … just perhaps less immediately apparent on an initial burst.

Apostle also represents another unexpectedly gnarly notch in the career of Dan Stevens, who has certainly not beaten an easy retreat into rigidly upright roles post-Downton Abbey. If The Guest and Legion didn’t eradicate all memories of dweeby Matthew Crawley, Apostle will decisively obliterate them.

Stevens plays Thomas Richardson, once a fervent missionary and now a husk wracked by laudanum and riddled with scars. After learning that a cult has taken control of his sister on Erisden, a remote Welsh island, Thomas taps into his more physically aggressive powers of persuasion — changing people’s minds by knocking their heads around.

But Malcolm Howe (Michael Sheen) will not yield so easily. He is the prophet on Erisden, a man who would just as soon sever arteries than any promise — or selling point — of his system. Malcolm preaches autonomy from bureaucratic taxation and persecution of beliefs. But the more we learn about Erisden — and what Malcolm and his lieutenants found upon arriving — the more we see his is an attempt at a power grab in isolation from intervening forces.

Erisden is a paradise in decline, a fetid feeling of rot and despair rolling over the island like a permanent fog. Cinematographer Matt Flannery captures both its idyllic fantasy and dying-land reality, and thanks to composers / sound designers Fajar Yusekemal and Aria Prayogi, Apostle feels and sounds like a rusty needle slowly inserted into your ear canal and twisted, twisted, TWISTED. Their music could best be described as “Goblin gone folk,” and it’s terrifying. In all, Apostle represents a far more unsettling auditory experience than any of the cacophony in Hereditary, and Evans also rewards the audience’s willingness to pay attention rather than indulging a self-satisfying shell game to obscure what’s really driving events on the island.

Eventually, Apostle breaks its hermetic seal to excavate skulls and separate appendages. It’s a viscerally exciting whiplash of tone, even as it risks losing sight of how incurable curiosity for illicit behavior spreads across the island — and religion in general — like unchecked infection. At the same time, it all builds up to an unnerving final shot that’s difficult to shake and which lends a retroactively malevolent purpose and power to the violence.

Apostle is a good film that might push higher when revisited. Maybe the willful surrender of blood in pursuit of a “purer” plane is a natural evolution for a guy who so thrillingly peddles the pummeling of soft flesh.

Apostle is now streaming on Netfilx.