'Well, I don't feel at all like a Viking. I'm not after loot, and adventure is the very last thing I want.'

'Then why – no, I don't intend to start another fight. But it would help us both, if you know exactly what your motives are.'

'I wish I could give you one single good reason. Instead, I've a whole host of little ones. But they add up to a final answer I can't argue with – believe me.'

'I believe you. But are you sure you're not fooling yourself?'

'If I am, then so are a lot of other people. Including, may I remind you, the President of the United States.'

'I'm not likely to forget. But suppose – just suppose – that he hadn't asked you. Would you have volunteered?'

'I can answer that truthfully: No. It would never have occurred to me. President Mordecai's call was the biggest shock of my life. But when I thought it over, I realized he was perfectly right. You know I don't go in for false modesty. I am the best-qualified man for the job – when the space docs give their final okay. And you should know that I'm still in pretty good shape.'

That brought the smile he had intended.

'Sometimes I wonder if you'd suggested it yourself.'

The thought had indeed occurred to him; but he could answer honestly.

'I would never have done so without consulting you.'

'I'm glad you didn't. I don't know what I'd have said.'

'I could still turn it down.'

'Now you're talking nonsense, and you know it. Even if you did, you'd hate me for the rest of your life – and you'd never forgive yourself. You have too strong a sense of duty. Maybe that's one of the reasons I married you.'

Duty! Yes, that was the key word, and what multitudes it contained. He had a duty to himself, to his family, to the University, to his past job (even though he had left it under a cloud), to his country – and to the human race. It was not easy to establish the priorities; and sometimes they conflicted with one another.