"Why, if what that captain said is true," she gasped, "it means somebody has invented a ship that can make interplanetary hops in three or four days."
"It means more than that, my sweet. (Here. Have some more steak; you can still put on a pound or two.) It means a new fuel has been found which will permit trips to the outer planets, make Moon Station obsolete and open up untold trade possibilities."
"Uh huh!" Her blue eyes opened wide and she reached across the table to grip his wrist. "It also may mean the end of all of us."
"Nonsense. They said that about the first fission bomb."
"And they were nine-tenths right, as you'll admit if you remember the history of the Atomic War. But this may be far worse. Look, let's figure it out. Remember what those bombs did to the cities of Earth. Well, they were loaded with Plutonium, the stuff we now use for rocket fuel.
"But Plutonium furnishes just enough power to lift a ship, its pilot, one or two passengers, and a few pounds of pay load from Venus or Mars to the Earth. A ship escaping from the stronger gravity of Earth can only limp as far as Moon Station without refueling. Do you follow me?"
"So far." Frank finished his traskette and motioned the waiter to bring more. "Go on."
"So if somebody has built a ship ten or fifteen times larger and faster than ours, it means...?"
"... that he has found out how to destroy atomic nuclei instead of merely splitting them by stripping off the electrons. In other words, he is possessed of a source of practically limitless power."
"Right." She patted his hand. "And now we come to the 64-credit question: Who is that somebody?"