She slips down the ladder, past her sleeping mother, and out the door, blanket trailing behind. In the Commissary two grown-ups walk on Perambulators, Vizers over their eyes, tomorrow’s schedule flickering in the air behind them—DayLight 110 Tai Chi in Library Atrium, DayLight 130 Bioengineering Meeting. She whispers down the corridor in her socks, past Lavatories 2 and 3, past the closed doors of a half-dozen compartments, and stops outside the door with the glowing edges marked Farm 4.

Inside, the air smells of herbs and chlorophyll. Grow lights blaze at thirty different levels on a hundred different racks, and plants fill the room all the way to the ceiling: rice here, kale there, bok choi growing next to arugula, parsley above watercress above potatoes. She waits for her eyes to adjust to the glare, then spots her father on his stepladder fifteen feet away, entwined in drip tubes, his head in the lettuces.

Konstance is old enough to understand that Father’s farm is unlike the other three: those spaces are tidy and systematic, while Farm 4 is a tangle of wires and sensors, grow-racks skewed at every angle, individual trays crowded with different species, creeping thyme beside radishes beside carrots. Long white hairs sprout from Father’s ears; he’s at least two decades older than the other children’s fathers; he’s always growing inedible flowers just to see what they look like and muttering in his funny accent about compost tea. He claims he can taste whether a lettuce has lived a happy life; he says one sniff of a properly grown chickpea can whisk him three zillion kilometers back to the fields he grew up in Scheria.

She picks her way to him and pokes his foot. He raises his eyeshade and smiles. “Hi, kid.”

Bits of soil show against the silver of his beard; there are leaves in his hair. He descends his ladder and wraps her blanket around her shoulders and guides her to where the steel handles of thirty refrigerated drawers protrude from the far wall.

“Now,” he says, “what’s a seed?”

“A seed is a little sleeping plant, a container to protect the little sleeping plant, and a meal for the little sleeping plant when it wakes up.”

“Very good, Konstance. Who would you like to wake up tonight?”

She looks, thinks, takes her time. Eventually she chooses a handle four from the left and pulls. Vapor sighs out of the drawer; inside wait hundreds of ice-cold foil envelopes. She chooses one in the third row.

“Ah,” he says, reading the envelope. “Pinus heldreichii. Bosnian pine. Good choice. Now hold your breath.”