Still puzzled, Eva had looked at that cryptic message day after day, trying to determine its true meaning. In time, she’d forgotten about it. A year later, she’d been removing her old clothing, which no longer fit, from her dresser drawers.

Once again, she’d spied the secret words.

“Show me the Sanctuary’s floor plan,” she had instructed the Omnipod when she was nine years old. Once again, a dazzling hologram had floated up, expounding in great detail about the different chambers of the girl’s home. Immediately, Eva had realized that there were holes in this hypnotic display—pieces of the Sanctuary that were missing. The Omnipod hadn’t been showing her everything.

Eva had asked to see the Sanctuary’s entire floor plan.

The Omnipod had asked for a username and a password.

Eva had replied, “CP01. Omniscient.” . . .

She now approached the halfway point of the long hallway. The humidity had increased as she’d trekked farther down the winding corridor. Moisture clung to the walls, and small fungi dotted the ceiling in places.

“Almost there,” whispered Eva, her voice echoing through the darkness. When Eva had first wandered into this new, uncharted area, she’d been thrilled and terrified all at once. Now she moved without hesitation. Her destination was just ahead. . . .

She remembered a time when she had realized there was more to the world than just her life in the Sanctuary. When she’d been six, she had asked Muthr about it as she’d sat down to breakfast. “Why aren’t there trees in our house?”

“Because trees cannot grow here,” Muthr had replied, dropping a pill into a cup of water. It had fizzed as it had plunged to bottom of the cup, disintegrating.

“But we have plants in our greenhouse. And my programs show trees. Big, enormous oak trees, growing in large forests,” Eva had said as she’d slurped up her drink. Muthr had told her the taste was like freshly picked oranges.

The robot had put an arm around her, “Well, Eva, there are trees. But they cannot grow here, where we live. They grow . . . above us.”

“Can we go and see them?” Eva had been excited at the idea of exploring a big forest towering right above them. “We could play hide-and-seek and have a picnic.”

“All in due time,” Muthr had replied, setting a bowl of oatmeal-flavored mush in front of her. All in due time. . . .

Eva finally arrived at the end of the hall. Another door, identical to the one she had opened in the supply room, stood shut in front of her, its manual control panel darkened from water damage. She knelt down, adjusting the light on the Omnipod from a solid beam to a soft, luminous glow.