Last summer, Rebecca Vance talked with her family about a dream she’d had: She wanted to live in a land disconnected from the world, which she viewed as chaotic and dangerous. She told her stepsister, Trevala Jara, that she could grow and gather her own food in a remote place, that she and her teenage son could be happy and safe away from the news, the viruses, the politics of modern-day America. “I’m going to worry about you,” Jara told her stepsister. But Vance was resolute. “I’m going to live off the land,” she replied. Her decision proved to be...