EXCERPT: “Can we stop?” asked Nikki, panting, her face tingling from the assault of the cold. Her fingers were numb, her nose running. Her lungs burned. “When we reach the trees,” her father said. He was a few feet in front of her, walking steadily against the wind. Ahead of them was an island of snow-capped pine trees. After hours of walking, the island—once just a small patch of green and white in the middle of the frozen lake—now loomed as an expanse of dense wilderness. The lake stretched behind them in every direction.