Ian and Sovra are thrilled when their father, Dr Kennedy, buys them a boat of their own. They make plans to cross the loch near their home on the west coast of Scotland and explore Castle Island. Here they discover a stone stairway hidden behind a waterfall and an abandoned shieling - the perfect place to camp. The arrival of the awful Mrs Paget and her irritating daughter, Ann, interferes with their plans to a degree, but Ian and Sovra still manage to explore the abandoned village of Kindrachill on the isolated Fionn-ard peninsula. There is a legend that when the village is left empty, the heir of Kindrachill will only return when a fire is kindled in the hearth of his own house. But the last heir, Alistair, was reported killed in the Far East some years before...