It was a big universe, with measureless millions of stars, and plenty of room for more than two intelligent civilizations. It wasn't surprising that the Lhari, who had only been traveling space for a couple of thousand years themselves, had never come across humans before. But they had been delighted to meet another intelligent race—and it was extremely profitable.

Because men were still held, mostly, to the planets of their own star-systems. Ships traveling between the stars by light-drive were rare and ruinously expensive. But the Lhari had the warp-drive, and almost overnight the whole picture changed. By warp-drive, hundreds of times faster than light at peak, the years-long trip between Vega and Earth, for instance, was reduced to about three months, at a price anyone could pay. Mankind could trade and travel all over their galaxy, but they did it on Lhari ships. The Lhari had an absolute, unbreakable monopoly on star travel.

"That's what hurts," Tommy said. "It wouldn't do us any good to have the star-drive. Humans can't stand faster-than-light travel, except in cold-sleep."

Bart nodded. The Lhari ships traveled at normal speeds, like the regular planetary ships, inside each star-system. Then, at the borders of the vast gulf of emptiness between stars, they went into warp-drive; but first, every human on board was given the cold-sleep treatment that placed them in suspended animation, allowing their bodies to endure the warp-drive.