Sinister terrors and a strange quest on a fogbound island where nothing is as it seems. This is another fast-paced, scary story featuring Peter and Katya, who are visiting Katya's father at his small pub/hotel on a remote Scottish island. But they bargain without their encounters with a priest in the ancient island cult of St Numnah, art thieves in pursuit of priceless treasures - and the story of the island's religious relic 'the Heart of St Numnah'.

Dangers abound with human baddies, gales and suffocating fog on an island already clouded with the terrors of its prehistoric cairns and standing stones ... Peter and Katya must again pit courage and wits against bizarre villains in a frantic race against time.