That all changed when she heard the roar. It was a deep rumble that seemed to make the very ground shudder, more geological than animal.

“What was that?”

“Bisesa? You asked a question?”

The voice was smooth, male, a little too perfect, and it came out of the air.

“Aristotle?” But she knew it could not be, even before he answered.

There was an odd delay before he replied. “I’m afraid not. I am Thales.”

“Thales, of course.”

Before the sunstorm there had been three great artificial intelligences on the human worlds, remote descendants of the search engines and other intelligent software agents of earlier technological generations, and all of them friends of mankind. There were rumors that copies of them had been saved, as streams of bits squirted off into interstellar space. But otherwise only Thales had survived the sunstorm, stored in the simpler networks of the sturdy Moon.

“I’m glad to hear your voice again.”

Pause. “And I yours, Bisesa.”

“Thales — why these response delays? Oh. Are you still lodged on the Moon?”

“Yes, Bisesa. And I am restricted by lightspeed delay. Just like Neil Armstrong.”

“Why not bring you down to Earth? Isn’t it kind of inconvenient?”

“There are ways around it. Local agents can support me when time delay is critical — during medical procedures, for instance. But otherwise the situation is deemed satisfactory.”

These responses sounded rehearsed to Bisesa. Even scripted.

There was more to Thales’s location on the Moon than he was telling her. But she didn’t have the spark to pursue the matter.