Still, Mara wasn’t sure about moving. She liked school and got good grades; she went twice a week to gymnastics lessons, and was learning a back handspring. After a few lonely years, she had developed a close friendship with another girl in her class. But she had a sense of adventure, and as an only child with few friends, was profoundly attached to her parents. When the family held a garage sale in their front yard, Mara gamely brought out boxes of toys and clothing, selling her treasures for quarters to the neighbors’ children, who had never shown any interest in her at all.

The weekend after Mara finished fifth grade, they drove east for half a day, stopping finally at a patch of dry grass and trees that looked, to Mara, indistinguishable from the grass and trees around it. But the land was theirs, her parents told her, giddy, and their excitement made Mara giddy, too. It had a pond, a rotten dock, a water pump, an outhouse, and potential.

Mara’s mom had quit her job at a bank, and her father his job as a builder. “We’re only building for ourselves now,” he told her, kissing her on the head. He had visions of an earth-bag dome, an eco-home well suited to the dry climate. He’d built one once for an eccentric client and found the process versatile and cheap.

All summer they slept in a tent on a wide foam mattress, with Mara in the middle. Her job was to fill bags with dirt. They were poly bags, each the size of a pillowcase, with the faded logo of a local waste-management company. Mara filled coffee cans with earth and gravel, then poured them into the bags one by one. It took twenty-six cans to fill each bag. When she was done, her dad would tie off the bag, hoist it, and arrange it with the others, which stacked in a ring like bricks. Mara’s favorite job was stomping on the stacked bags to flatten them. The bags were heavy, but her parents were strong.

When she was bored, she went to the pond and caught frogs, or collected roly-polies in a box. A neighbor girl came by sometimes. Her name was Stormy, and she was only nine, which seemed then a significant age difference. But she’d grown up on the next forty, and she knew everything about the land. She taught Mara how to peel open honeysuckles and eat the nectar, and where to find fossils of shells in the rocks, though they were hours from the sea. When her dad was out hunting, she showed Mara his bunker, which was hidden under a wooden deck. It looked like plain wood until you lifted a special plank and found a ladder leading into darkness. The girls climbed down, daring each other to touch the dirt floor, pretending not to be scared, and it felt like freedom climbing back to the light.

One day Mara found a snakeskin in the grass. It was a whole skin, almost three feet long, and tied in a loose knot. As if the snake had curled through itself to shed. She thought about showing it off, but the snakeskin felt like hers alone, a secret, and she snuck it into one of the earth bags, nestled between one layer of dirt and the next. A talisman; her own contribution to the build. She told Stormy the next day.