Book excerpt: At the start of winter, two bear cubs are born, deep in their den in the frozen north. "Mama, what lies beyond here?" they ask. "‘Above us is a land of ice and snow." "What lies beyond the ice and snow?" they ask. "The ocean, full of ice from long ago." And as they learn the secrets of the earth and their place in it, Mama Bear whispers, “You’re snug with me.”