Police Sergeant Neil Howie (Edward Woodward) journeys to the remote Hebrides island Summerisle to investigate the disappearance of a young girl, Rowan Morrison (Gerry Cowper), about whom he has received an anonymous letter. Howie, a devout Christianity, is disturbed to find the islanders paying homage to the Paganism Celts gods of their ancestors. They copulate openly in the fields, include children as part of the May Day#Traditional May Day celebrations, teach children of the phallic association of the maypole, and place toads in their mouths to cure sore throats. The Islanders, including Rowan's own mother (Irene Sunters), appear to be attempting to thwart his investigation by claiming that Rowan never existed.