Robert Eggers’s gripping nightmare shows two lighthouse-keepers in 19th-century Maine going melancholy mad together: a toxic marriage, a dance of death. It is explosively scary and captivatingly beautiful in cinematographer Jarin Blaschke’s fierce monochrome, like a daguerreotype of fear. And the performances from Willem Dafoe and Robert Pattinson have a sledgehammer punch – Pattinson, in particular, just gets better and better.

There is rare excitement in seeing these two actors butt heads and trade difficult, complex period dialogue with such mastery and flair. And the screenplay by Robert and Max Eggers is a delicious and often outrageous homage to maritime speech and sea-dog lore, saltier than an underwater sodium chloride factory. Their script is barnacled with resemblances to Coleridge, Shakespeare, Melville – and there’s also some staggeringly cheeky black-comic riffs and gags and the two of them resemble no-one so much as Wilfrid Brambell and Harry H Corbett: Steptoe and Son in hell.



Dafoe and Pattinson are Tom Wake and Ephraim Winslow – stern, taciturn men with pipes or bits of cigarette habitually jammed in the corner of their unsmiling mouths, about to start a four-week stretch of duty on a remote, wind-lashed rock to tend the lighthouse there. Tom is the ageing veteran “wickie”, a former able seaman now disabled with a leg injury whose cause is mysterious: he is the senior officer, with sole charge of the light itself, a privilege that makes him petulant and querulous.



Ephraim left his logging job in Canada for this post, and he has the lesser, more arduous and demeaning jobs of maintaining the rotational machinery, gathering firewood, emptying the chamberpots, whitewashing the light-tower, mending and cleaning. From the very first, he is glowering and resentful, furious at Tom’s bantering and baiting - one moment joshing the youngster, the next moment angrily pulling rank with deadly seriousness. Ephraim is annoyed that he is never allowed near the light - and then suspicious and terrified to be told that Tom’s former assistant died of lunacy due to bizarre visions. But is that the whole truth? Ephraim himself has deeply disturbing and intimately erotic visions of a mermaid which cause him to masturbate frantically, despairingly, in the woodshed. Eventually, the loneliness, the frustration and periodic bouts of drunkenness take their toll, and Ephraim in a hysterical rage does something awful which disturbs the balance of the heavens themselves, and Mark Korven’s musical score ratchets up the tension ruthlessly.



What is so exhilarating and refreshing about The Lighthouse is that it declines to reveal whether or not it is a horror film as such, though an early reference to Salem, Massachusetts gives us a flashback to Eggers’s previous film, The Witch (2015). It is not a question of a normal-realist set-up pivoting to supernatural scariness with reliably positioned jump-scares etc. The ostensible normality persists; perhaps something ghostly is going on, or perhaps this is a psychological thriller about delusion. But generic ambiguity is not the point: The Lighthouse keeps hold of us with the sheer muscular intelligence and even theatricality of the performances and the first-class writing. Even Sir Donald Wolfit or Robert Newton could not have got more out of the role of Tom than Willem Dafoe does and Pattinson is mesmeric in his bewilderment and uncertainty.



The two men veer wildly between enmity, comradeship, father-son intimacy, father-son hatred. They get drunk together, they get hungover together, but they are keeping secrets from each other - and Ephraim, excruciatingly aware of his lower status, suspects that Tom’s secret is more important than his, and could kill him.



Apart from everything else, this is a sublime film visually: Eggers and Blaschke imagine a glorious variety of images from this stark and unforgiving place. Very few films can make you scared and excited at the same time. Just like the lighthouse beam, this is dazzling and dangerous.