"Nonsense," said Anti. "I don't feel the weight."
"You don't and won't," said Docchi. "The gravity drive was installed to propel the ship. When it was proved unsatisfactory for that purpose it was converted, which was cheaper than removing it.
"The difference between the drive and ordinary gravity is slight but important. An undirected general field produces weight effects inside the ship. That's for passenger comfort. A directed field, outside it, will drive it. You can have one or the other but not both."
"But I didn't turn on the drive," said Jordan in bewilderment. "It wouldn't work for more than a few seconds if I did. That's been proven."
"I'd agree with you except for one thing. It is working, has been working and shows no sign of stopping." Docchi stared speculatively at Nona. She was curled up but she wasn't resting. Her body was too tense. "Get her attention," he said.
Jordan gently touched her shoulder. She opened her eyes but she wasn't looking at them. On the panel the needle of a once useless dial rose and fell.
"What's the matter with the poor dear?" asked Anti. "She's shaking."
"Let her alone," said Docchi. "Let her alone if you don't want to return to the asteroid." No one moved. No one said anything. Minutes passed and the ancient ship creaked and quivered and ran away from the fastest rockets in the system.
"I think I can explain it," said Docchi at last, frowning because he couldn't quite. There were things that still eluded him. "Part of the gravity generating plant—in a sense the key component—is an electronic computer, capable of making all the calculations and juggling the proportion of power required to produce directed or undirected gravity continuously. In other words a brain, a complex mechanical intelligence. But it was an ignorant intelligence and it couldn't see why it should perform ad infinitum a complicated and meaningless routine. It couldn't see why and because it couldn't very simply it refused to do so.
"It was something like Nona. She's deaf, can't speak, can't communicate in any way. Like it she has a very high potential intelligence and also, in the very same way, she's had difficulty grasping the facts of her environment. Differently though, she does have some contact with people and she has learned something. How much she knows is uncertain but it's far beyond what psychologists credit her with. They just can't measure her type of knowledge."