"I know," he said. He could not make out any detail, but there they were, just as they had been for—how long? Ten thousand years? A hundred thousand? Five towers jutting straight up from the bleak plain, clustered around a central, taller tower.
"Is the machinery still running?" he asked, pointlessly.
"Of course."
"There was some talk a year or so back about trying to stop it."
She shook her head. "They wouldn't dare."
The machine had been discovered more than ten years earlier, when the first Earthmen landed on Titan. Saturn's largest satellite was devoid of life, a world of dark and cold, of hydrogen atmosphere and methane clouds, of ammonia seas and ice mountains.
And there in the midst of it all stood the machine: a brazenly unconcealed cluster of mammoth buildings, with its five stately towers surmounted by the soaring central sixth. And within, row upon row of unexplained machinery, fully automated, operating continuously in perfect order.
Alien.
The discoverers soon concluded that the machine was unbelievably old, older than the Egyptian pyramids, perhaps even older than the Martian canals. And it was running smoothly. For untold centuries, for uncounted millennia, it had continued to operate efficiently, tended only by automatic machines.