> "It's amazing when you think of it," said Adell. His broad face had lines of weariness in it, and he stirred his drink slowly with a glass rod, watching the cubes of ice slur clumsily about. "All the energy we can possibly ever use for free. Enough energy, if we wanted to draw on it, to melt all Earth into a big drop of impure liquid iron, and still never miss the energy so used. All the energy we could ever use, forever and forever and forever."
> Lupov cocked his head sideways. He had a trick of doing that when he wanted to be contrary, and he wanted to be contrary now, partly because he had had to carry the ice and glassware. "Not forever," he said.
> "Oh, hell, just about forever. Till the sun runs down, Bert."
> "That's not forever."
> "All right, then. Billions and billions of years. Ten billion, maybe. Are you satisfied?"
> Lupov put his fingers through his thinning hair as though to reassure himself that some was still left and sipped gently at his own drink. "Ten billion years isn't forever."
> "Well, it will last our time, won't it?"
> "So would the coal and uranium."
> "All right, but now we can hook up each individual spaceship to the Solar Station, and it can go to Pluto and back a million times without ever worrying about fuel. You can't do that on coal and uranium. Ask Multivac, if you don't believe me.
> "I don't have to ask Multivac. I know that."
> "Then stop running down what Multivac's done for us," said Adell, blazing up, "It did all right."
> "Who says it didn't? What I say is that a sun won't last forever. That's all I'm saying. We're safe for ten billion years, but then what?" Lupow pointed a slightly shaky finger at the other. "And don't say we'll switch to another sun."
> There was silence for a while. Adell put his glass to his lips only occasionally, and Lupov's eyes slowly closed. They rested.