Powell and Pressburger were trying to make A Matter of Life and Death, but wartime Britain was rationing Technicolor stock and shipping every reel to the Ministry of Information. So they pivoted. Pressburger suggested a film that continued the "crusade against materialism" they had begun in A Canterbury Tale - this time as accessible romantic comedy. He wanted, he said, a story about a girl who wants to get to an island, but by the end of the film no longer wants to. Powell suggested Scotland's west coast. They spent weeks scouting and settled on the Isle of Mull. The original working title was The Misty Island. Wendy Hiller stepped in when Deborah Kerr could not break free of her MGM contract; Roger Livesey asked for the male lead and lost ten pounds to convince Powell he was right for it. He never made it to Scotland, though, because he was performing in a Peter Ustinov play in the West End. His scenes were shot in Denham Studios against back projections.

Joan Webster is twenty-five, ambitious, upper middle class, and engaged to Sir Robert Bellinger, an industrialist near her father's age who has rented an entire Hebridean island called Kiloran. She "always knows where she's going." On the Isle of Mull, fog and gale halt the boat to Kiloran. Stranded, she meets Torquil MacNeil, a Royal Navy officer on shore leave who is also trying to get to Kiloran - because, it transpires, he is the laird; Bellinger is only renting his island for the duration of the war. The locals do not know who Joan is, and on the bus they cheerfully describe Bellinger as a man not worth knowing. At a ceilidh celebrating a couple's diamond wedding, three pipers - stranded with her, hired for her wedding - play "Ho ro, mo nighean donn bhoidheach," the Gaelic song English-speakers call "Nut-Brown Maiden." Torquil translates the line "You're the maid for me." Joan dances brilliantly and is in trouble.

Desperate to escape what is happening to her, Joan pays a boatman's young mate twenty pounds to attempt the crossing alone, in a gale, and Torquil insists on coming with her. Their boat is caught in the Corryvreckan whirlpool. Powell and his cinematographer Erwin Hillier shot the sequence by stitching together four kinds of footage: long shots from the Scottish islands looking down on the real whirlpool, hand-held shots from a small boat in slightly tamer waters at the Sound of the Grey Dogs, model shots in a Denham studio tank with gelatin added to the water so its waves would scale, and close-ups of the actors in a wooden boat mounted on gimbals while studio hands threw buckets of water at them. Hillier, who shot the entire film without a light meter, conjured a black-and-white Hebrides that smells, as Raymond Chandler later wrote, "of the wind and rain."

Earlier in the film Joan and Torquil walk past the ruins of Moy Castle. Torquil refuses to enter. The curse, he explains, applies to any MacNeil laird who crosses the threshold: he will be chained to a woman until his death. The story of the curse is medieval and grim - a wife and her lover bound together and lowered into the castle's water-filled well, dragged each other under at the end - and the film treats it as a riddle to be solved rather than a warning to be heeded. After Joan leaves on the clearing weather, Torquil walks into Moy and reads the inscription. From the battlements he sees her returning, preceded by the three pipers playing "Nut-Brown Maiden." They meet in the castle. The curse, it turns out, was a promise.

The film was a hit, recouping its cost in the United Kingdom alone and taking $1.2 million in the United States. Critics were generous about everything except the plot. The Monthly Film Bulletin praised "affectionate and sympathetic handling of the Highland setting" while admitting the story "does not bear reflective analysis." Pressburger said Paramount's script department in 1947 kept a copy on hand for inspiration. The film has aged into something more than entertainment: a record of a Highland culture - the ceilidh, the falconer with his eagle, the bus full of locals, the boatman with his Gaelic - that the war was already beginning to dissolve. It is the rare film of the period made with affection for a place rather than romantic projection onto one. Joan was going the wrong way. So, the film argued, was much of Britain.