Nigel Grumley has always wanted to live in a castle – just like Ulric the boy-prince in his favourite novel, The Bloodstone of Carrickfergal. So when his dad has one of his ‘Brilliant Ideas’ and buys a 700 year-old English castle, Nigel thinks all his dreams have come true. Except that Castle Grimwold is 5,000 miles away from home, a complete ruin and possibly the only castle in Europe that doesn’t have a dungeon, or a secret passageway – or anything. Nigel isn’t the only one who’s not impressed. His mother is furious and his older sister Ness - a death metal-loving teen Vampira who calls her brother ‘Stupid’ - becomes even meaner and more ferocious than usual. But Nigel is wrong about Castle Grimwold’s total lack of mystery. Nigel and Ness reluctantly band together to solve the castle's secrets and discover that they are in fact the guardians of an ancient faery portal that is the gateway between the living and the dead. Soon they find themselves in a centuries-old struggle with the evil Black Druid Mandragore who plans to use the portal to bring all living creatures under his control.