It's December 1967, and the town of Kinloch is cut off by heavy snow. With all roads closed, the only way to feed and water the townsfolk is for the fishing fleet to sail to Girvan for much-needed supplies.
But the skipper of the Girl Maggie, Sandy Hoynes, has a problem. First mate Hamish has, to everyone's astonishment, been chosen as Young Fisherman of the Year by a Glasgow newspaper. Marooned in the town and with one eye on a scoop, their reporter decides to join the fishing crew on the mercy mission. The thought of the publicity — and some remuneration — delights Hoynes. But Hamish hasn't told him the whole story.
As the blizzards worsen, the crew of the Girl Maggie embarks upon a trip like no other, encountering ghostly Vikings, gigantic crustaceans and a helpful seagull.