Petra loves rocks, and collects them with a passion. She keeps them in her bedroom, in the kitchen cupboards, between the cushions of the living-room sofa, even in the bathroom medicine cabinet. Petra’s parents do not love rocks. At least, not as much as Petra does. To convince her to winnow down her collection, her parents offer her a wonderful treasure—a rock box, with a selection of the rocks and minerals found in her home province of Newfoundland and Labrador. But, wait, is one of those rocks winking at her?