She hurried to an area where the drones were already setting up lights. “See these tracks? They were cut by flowing water!” She knelt and pointed. “They had a stream, feeding recycled water into a little lake there!

Dust sparkled as it slid through her gloved fingers “I’ll wager this was topsoil! And look! stems! From plants, and grass, and trees!”

“Put here for aesthetic purposes,” Gavin proposed. “We class AAA’s are predesigned to enjoy nature as much as you biologicals…”

“Oh, posh!” Ursula laughed. “That’s only a stopgap measure until we’re sure you’ll keep thinking of yourselves as human beings. Nobody expects to inflict a love of New England autumns on people when we become starships! Anyway, a probe could fulfill that desire simply by focusing a telescope on the Earth!”

She stood up and spread her arms. “This habitat was meant for biological creatures! Real, living aliens!”

Gavin frowned, but said nothing.

“Here,” Ursula pointed as they entered another chamber. “Here is where the biological creatures were made! Don’t these machines resemble those artificial wombs they’re using on Luna now?”

Gavin shrugged grudgingly.

“Maybe the organic creatures were specialized units,” he suggested, “intended to work with volatiles. Or perhaps the type of starprobe that built this facility needed some element from the surface of a planet like Earth, and created workers equipped to go get it.”

Ursula laughed. “It’s an idea. That’d be a twist, hmmm? Machines making biological units to do what they could not? And of course there’s no reason it couldn’t happen that way.

“Still, I doubt it.”

“Why?”

She turned to face her partner. “Because almost anything available on Earth you can synthesize more easily in space. Anyway…”