He paused and glanced at one of his assistants questioningly. The man, a mousy individual named Kesser, said:

'It happens that I'm in disagreement with the electrical-storm theory, though I also agree on the presence of masses of gas. After all, that's old stuff in astronomy. But now – my explanation for the sparks. As long ago as the twentieth century, perhaps even earlier, it was theorized that the gas molecules and atoms floating in space readily interchanged velocity for heat or heat for velocity. The temperatures of these free particles, when such an interchange occurred, was found to be as high as twenty thousand degrees Fahrenheit.'

He looked around, momentarily very unmouselike. 'What would happen if a molecule traveling at such speed struck our ship? Sparks of heat, of course.' He paused. He was a graying man with a hesitant way of speaking. 'And then, of course, we must always remember the first Centaurus expedition and be doubly careful.'

There was a chilled silence. It was strange but Lesbee II had the impression that, although everybody had been thinking of the first expedition, nobody wanted it mentioned.

Lesbee II glanced at his father. Captain Lesbee was frowning. The commander had grown more spare with years, but his six feet three inches still supported 175 pounds of bone and flesh. He said:

'It is taken for granted that we shall be cautious. One of the purposes of this voyage is to discover the fate of the first expedition.' His gaze flashed toward the group of physicists. 'As you know,' he said, 'that expedition set out for Alpha Centauri nearly seventy-five years ago. We are assuming that the engines would have kept going. Therefore, some control would have existed in any fall through the atmosphere of a planet, and a trace of its presence will remain. The question is, what would be operable after three quarters of a century?'

Lesbee was amazed at the various answers.