Cory, just flown in from the East Coast, happy to escape the gypsy life of her actress foster-mother, arrives at her Uncle Dirk's cliffside estate via a wild walk in a storm, let by a newly met friend, Peter. She is welcomed into the wonderful cottage kitchen of the Scots caretakers, Fergie and her husband Andrew, who jokes that Cory is "cawry-fisted" — left-handed — and therefore must be bewitched, or at least enchanted. And indeed, Cory comes to imagine, she and everyone connected with the estate of Tarnhelm seem to be under a spell. Dreams and mysteries abound. Why is her wonderful Uncle Dirk so moody? Why does her grandmother say she must not stay there long? Who is Laurel, the woman she meets on the beach? Who sat for the unfinished mask she and Peter found in an unused tower of the house? Will she ever be deemed brave enough to join Peter's peer group, the Explorers? Why has her foster mother Stephanie never formally adopted her? To answer the questions, and break the spell on Tarnhelm, Cory must follow her heart, her left hand wrapped for luck around her unicorn amulet.