"They'll learn they must!" growled Walker. Then he said abruptly: "What repairs does your ship need? We'll bring it here and repair it, and then you'll take our prisoner and carry him and your message back to his own kind—our children!" The irony and the fury and the frustration in his tone as he said, "children," made Murgatroyd wriggle, underneath Calhoun's coat. "I find," said Calhoun, "that all I need is power. You drained my overdrive charge when you snatched my ship out of overdrive. I've extra Duhanne cells, but one overdrive charge is a lot of power to lose." "You'll get it back," growled Walker. "Then take the prisoner and our warning to Canis. Get them to surrender if you can." Calhoun considered. Under his coat, Murgatroyd said "Chee! Chee!" in a tone of some indignation. "Thinking of the way of my own father with me," said Calhoun wryly, "and accepting your story itself as quite true—how the devil can I make your children believe that this time you aren't bluffing? Haven't you bluffed before?" "We've threatened," said Walker, his eyes blazing. "Yes. And we were too soft-hearted to carry out our threats. We've tried everything short of force. But the time has come when we have to be ruthless! We have our wives to consider." "Whom," observed Calhoun, "I suspect you didn't dare have with you because they wouldn't let you actually fight, no matter what your sons and daughters did." "But they're not here now!" raged Walker. "And nothing will stop us!" Calhoun nodded. In view of the situation as a whole, he almost believed it of the fathers of the colonists on Canis III. But he wouldn't have believed it of his own father, regardless, and he did not think the young people of Canis would believe it of theirs. Yet there was nothing else for them to do. It looked like he'd traveled three months in overdrive and painstakingly studied much distressing information about the ancestors of modern men, only to arrive at and witness the most heart-rending conflict in human history. III. "The fact that one statement agrees with another statement does not mean that both must be true. Too close an agreement may be proof that both statements are false. Conversely, conflicting statements may tend to prove