By Erica Abeel

The Lighthouse generates dark humor from the madness of toxic males gone rogue — wired to dominate, even as they self-destruct.

Willem Dafoe and Robert Pattinson in “The Lighthouse.” Photo: A24

The Lighthouse, directed by Robert Eggers. Screening at the Somerville Theatre, Coolidge Corner Theatre, AMC Boston Common 19.

Just one of many marvels of The Lighthouse is the way it’s pitched uneasily between genres. You scarcely know what you’re looking at. Is it a psycho-thriller? horror film? uproarious dark comedy? all of the above? And that ambiguity is what makes The Lighthouse the year’s most enthralling film to date. In this much anticipated sophomore work from director Robert Eggers (a follow-up to his Sundance hit The Witch), an old seadog and his novice assistant arrive circa 1890 on a desolate islet of sea, wind, and battered rock to tend a lighthouse for four weeks. Thomas Wake, the bearded, limping elder (Willem Dafoe), is ostensibly schooling the younger Ephraim Winslow (Robert Pattinson), a former logger, in the craft of lighthouse-keeping. But it quickly becomes apparent that Tom’s agenda is to play master to Ephraim’s galley slave, to oversee the latter’s back-breaking labors with a sadistic glee that shouts Male Dominance.  Young Ephraim, surly, recessive, hiding mysterious baggage, has no choice, at first, but to submit — until he doesn’t.

Trapped in a vexed proximity, the men eat dinner together lit by a single candle. Tom eagerly hits the hooch while he verbally pummels Ephraim. The younger man seems leery of alcohol, which Tom interprets as a fear of “spilling his beans.” When, inevitably, Ephraim drinks up, these barnacled specimens dole out dank snippets of themselves. Tom —  hilariously prone to declaiming a mixtape of Shakespeare and outtakes from Moby Dick — sums up his marital history with the refrain, “Thirteen Christmases at sea, little ones at home, she never forgave me.” Whatever is eating at Ephraim lies beyond his ability to articulate it, but Pattinson’s haunted, hunted gaze suggests volumes. Spotting Ephraim’s vulnerability, Tom gleefully pegs him as “a drifter” fleeing his past.

The men dance, carouse, wake in an alcoholic stupor locked in an embrace and then back off.  The homoerotic note is clear. In one scene, Tom forces Ephraim to whitewash the steep vertical of the lighthouse. Their only diversion is to masturbate. Tom seeks the privacy of the lighthouse summit housing the great revolving beam — a place he always keeps under lock and endows with mystical powers. Ephraim creeps off to the woodshed with the figurine of a mermaid he has pried, suggestively, from a slit in his mattress. These visits are occasionally supplemented by visions of a live, anatomically alarming mermaid (Eggers says he was inspired by shark genitals).

When a vicious storm pounds their remote outpost, the men miss the boat that was to deliver them. The initial four weeks turn sinisterly open-ended. After the booze runs out, they guzzle kerosene and descend into a mad doomed dance peopled with real or imagined ghosts. Boundaries dissolve in the fog, the island becomes an extension of their minds: seagulls, Tom claims, are the “souls of sailors that met their maker.” In Ephraim’s dreams Tom morphs into a monstrous Neptune. The balance of power between the men shifts to horrifying effect.

You’ll not soon see another film so rich in cultural references. Visually, The Lighthouse is a knockout. To lend his story the patina of the otherworldly and mythic, Eggers (who co-authored the screenplay with his brother Max) shot in gleaming black-and-white, using an old-fashioned 1.19:1 aspect ratio (a nearly perfect square, like early sound movies). The director melds a number of arty influences into an organic whole: silent film, particularly by focusing on his actors’ hyper-expressive eyes; German Expressionism via the use of stark angles and paranoid pictorals; Symbolist painters by way of Jean Delville and Arnold Bocklin (Bocklin’s shivery Isle of the Dead springs to mind; a shot of Dafoe’s naked white body echoes Delville’s painting of Prometheus).

Equally meticulous is the director’s search for the right linguistic register. Eggers researched the journals of lighthouse keepers (“wickies”) of the period; Herman Melville; the works of New England poet and novelist Sarah Orne Jewett. “Make those floors sparkle like a whale’s pecker,” Tom orders Ephraim in magisterial tones. The sound design — blasts of foghorns sound as if they are being belched from Hell — is practically a character in itself.

A warning: those expecting The Lighthouse to be a conventionally scary, jump-in-your seat horror film will be disappointed. This narrative is, above all, uproariously funny. Obsessive rigidity has long been fodder for comedy (think Moliere and The Miser). Eggers generates dark humor from the madness of toxic males gone rogue — wired to dominate, even as they self-destruct. He elevates the somberness of folkloric New England into high camp. Tom and Ephraim (whose real name also turns out to be Tom, making you wonder what, exactly, he’s hiding) are archetypal uptight yokels of that period — on steroids.

Instead of groping for understanding, the men use each other’s confessions of vulnerability as a means to get a one-up on the other. “You spilled your beans,” Tom’s voice mockingly echoes throughout the storm-battered lighthouse. The two exemplary actors sledgehammer each other with  hilariously machine-like precision. Pattinson, who has mainly excelled as a recessive type (as in David Cronenberg’s Cosmopolis), simmers with withheld fury. His is a grueling physical performance — cleaning cisterns and schlepping heavy loads in a wheelbarrow during bouts of driving wind and rain. The actor finally explodes in memorable rage, a high point in his development as an actor. Ultimately, though, it’s Dafoe’s show. That crabby-ass, pirate-y voice he’s devised to bark orders at Ephraim or to deliver grandiloquent speeches is priceless. The actor’s round, power-hungry eyes reflect psychic squalor: the warped soul of a man determined to dominate his fellow human, maybe as a means to keep his own demons at bay. For all his dominating strength, Tom is plainly obsessed (Ahab-esque?) with the luminous, rotating beacon of glass atop the lighthouse. At one point he roars, “No man shall touch her but myself.” What the hell is actually up there? Eggers is tight-lipped: “Nothing good happens when two men are left alone in a giant phallus.”

Erica Abeel is a novelist, film and cultural critic, and former professor at CUNY. Her journalism has appeared in the New York Times, Indiewire, and other major sites and publications. Wild Girls, her most recent novel, was praised by Oprah Magazine as a “libidinous period novel [that] follows three budding feminists through an elite women’s college, the New York art scene, and Allen Ginsberg’s bed, as they redefine womanhood for themselves and future generations.”