He added quickly, 'Oh, I realize lectures were given on the subject but, knowing you, I feel that they were what you wanted people to believe in the interests of the voyage. What's the truth?'

The old man's eyes twinkled suddenly, then he chuckled. 'I really turned out to have a natural instinct for knowing how to maintain discipline and morale, didn't I?' He grew somber. 'I wish I could inject some of that into you.' He broke off. 'But never mind. Your observation is correct. I told the people what I wanted them to think. The actual truth is substantially what I have already told you. When Tellier discovered that the ejected particles could not be speeded up to the point where they would expand, it became necessary to conserve our fuel supply. Theoretically, particles expanded to the level predicted for them at the velocity of light would have given us almost infinite power on a thimbleful of fuel. As it is, we used up hundreds of tons of fuel to get the ship up to 15 per cent of light-speed. Since by that time, we could calculate our fuel situation in terms of simple additive and subtractive arithmetic, I ordered the engines shut off. We've been coasting ever since at that speed. We'll have to use an equal amount of fuel tonnage to slow down when we get to Centaurus. If things work out when we arrive there, then, of course, no problem. But if they don't, then somewhere, sometime, we're going to pay the price for Tellier's failure.'

'What price?' Lesbee II asked.

'No fuel,' said his father laconically.

'Oh!'

'One more thing,' said the old man.