For the first time, Fraq made a gesture she understood. A shrug.

“Seldom.”

“So what did these ancient aliens do?” She had a suspicion, but needed to have it said.

“They went to… Mars. Where they thought it more likely that intelligence would arise.”

Rachel sucked in a deep breath. Humans thought in very narrow time scales, she knew. A SETI Librarian had to keep that in mind, always. But Mars had been wet and warm and its Marsmat life arose then to heights, well over a billion years ago. Rachel pulled up from memory the little she knew about that. “Well, we do know that the Marsmats deep in their caves have some symbol-arranging ability.”

The translator conveyed this, and after more odd alien sounds nodded with satisfaction. “Fraq will give us a symbol-set that the Marsmat may recognize. His kind used it in communicating with them, when they visited our solar system.”

Natal had no idea what time scale they were speaking about, obviously. Maybe all this had happened many million years back, when the Marsmat was firmly boxed in underground. Primates were pretty crude then, and not easy to find in the forests. If Fraq’s kind had visited Earth, they might have checked to see if we had black smokers. Or more likely, they saw the big, ugly life on land and decided they didn’t like it.

Fraq made an odd double-hand gesture that Rachel had learned meant Agreement with pleasure.

Rachel echoed his gesture. On to Mars, then. These puzzles run deep. Rachel felt the abyss of time they spoke of, and the vast differences between them, a dizzy swirl. She wondered if indeed life on Earth had started from those black smokers. SETI was supposed to tell humans about others, but… How odd, to learn so intimate a fact… from an alien.

PART 11 THE LATHE OF EVOLUTION

The world will never starve for wonders; but only for want of wonder.

—G. K. CHESTERTON

1.

The depths of Mars fell away into murk. The Descent Team grew quiet as they rose. It had been a confusing, chaotic few hours, and Zuminski ordered everyone to stop chatting about it.

“Time to let this sink in,” he said as the gray Martian bedrock glided by them.

Rachel agreed. Her SETI Library team was shaken. Their first descent had not gone remotely like their plans of an orderly tour and review of the Marsmat. The setup of the usual display panel, moving on to a display of Fraq’s symbol-string, had gone well. But then the Mat had flooded the principal entrance chambers with black fluid. The sudden dark flow had knocked them all off their feet, panicking even the seasoned Descent Team.

They got trapped, fought their way free.

Nothing like it had happened before, in all the history of Marsmat contacts. The warm, somehow sinister waters had lapped around them as they waded out.