"No other empire was ever built," said Edri quietly, "without any competition. I think you still don't quite understand. We have an absolute, complete, and unbreakable monopoly on interstellar flight. Only the Vardda ships go between the stars, and only the Vardda men can fly them. You know the reason, you proved it in yourself. We don't have to fight." Trehearne let go a long, low whistle. "And we thought we had monopolies on Earth! But I don't see why, if you could mutate, others couldn't do it, too. How do you hold them down?" "We don't hold anybody down. We don't rule, influence, or interfere with any world but our own. We learned long ago that it was bad business. As to the mutation, it's impossible. The secret of the process was lost with Orthis, some thousand years ago." He rose abruptly from the chair where he had been sitting, and pointed to some garments in the locker. "I think those will fit you. Get dressed, and I'll show you around." Trehearne looked doubtfully at the clothes, a tunic of dark green silk, dark trousers, a modestly jewelled belt, and sandals. Edri grinned. "You'll get used to them. And you won't feel half as peculiar as you would look going about in those ridiculous tweeds." Trehearne shrugged, and put them on. He had to admit they were comfortable. There was a mirror set inside the locker door, and he studied himself in it. He was startled to see how changed he was in the Vardda dress. The last vestige of Earth was gone. Still looking into the mirror, he said, "Edri...." "Yes?" "I am a Vardda now. I've proved it. What can they do to me, on Llyrdis?" "I wish I could tell you. Actually, you are a true Vardda, a complete atavism. But legally--that's another thing. That basic tenet of Vardda law that Kerrel referred to is a prohibition against admitting into our race non-Vardda strains of any kind. Keeping the Vardda blood pure isn't just pride, it's an economic necessity, and the one unbreakable tabu. The solution of that puzzle will be up to the Council, and my advice is to forget it until then. Come on, and I'll give you something else to think about." Trehearne was glad enough to go. The lost, sick, nightmarish feeling was creeping back on him again, and he was glad of any diversion. They went out into the corridor, and he followed Edri forward. He became aware of a deep inner vibration of power that filled the ship, a sort of humming drone that seemed to challenge the whole universe to make it stop. It sang in his ears, in his blood and his quivering nerve-ends, and the excitement he had felt when he first saw the ship returned to him full force. This was the ultimate. All his life he had been playing with children's toys, but here, under his feet and all around him, was the highest dream of men. "What's the motive power? What's the principle? And how can you go faster than light? The limiting speed, contraction, mass...."