"Just something stirring around in my mind. I was wondering where Chambers does most of his trading." "Ranthoor now," said Greg. "Used to do it on Venus. The listing is larger there. But since he took over the Jovian confederacy, he switched his business to it. The transaction tax is lower. He saw to that." "And the same shares are listed on the Callisto market as on the New York boards?" "Naturally," said Greg, "only not as many." Russ watched the smoke from his pipe. "How long does it take light to travel from Callisto to Earth?" "Why, about 45 minutes, I guess. Somewhere around there." Greg sat upright. "Say, what's light got to do with this?" "A lot," said Russ. "All commerce is based on the assumption that light is instantaneous, but it isn't. All business, anywhere throughout the Solar System, is based on Greenwich time. When a noon signal sent out from Earth reaches Mars, it's noon there, but as a matter of fact, it is actually 15 minutes or so past noon. When the same signal reaches Callisto, the correct time for the chronometer used in commerce would be noon when it is really a quarter to one. That system simplifies things. Does away with varying times. And it has worked all right so far because there has been, up to now, nothing that could go faster than light. No news can travel through space, no message, no signal can be sent at any speed greater than that. So everything has been fine." Greg had come out of the chair, was standing on his feet, the glow of the blaze throwing his athletic figure into bold relief. That calm exterior had been stripped from him now. He was excited. "I see what you are getting at! We have something that is almost instantaneous!" "Almost," said Russ. "Not quite. There's a time lag somewhere. But it isn't noticeable except over vast distances." "But it would beat ordinary light signals to Callisto. It would beat them there by almost 45 minutes." "Almost," Russ agreed. "Maybe a split second less." Greg strode up and down in front of the fireplace like a caged lion. "By heaven," he said, "we've got Chambers where we want him. We can beat the stock quotations to Callisto. With that advance knowledge of what the board is doing in New York, we can make back every dime I've lost. We can take Mr. Chambers to the cleaners!" Russ grinned. "Exactly," he said. "We'll know 45 minutes in advance of the other traders what the market will be. Let's see Chambers beat that." _CHAPTER SEVEN_ Ben Wrail was taking things easy. Stretched out in his chair, with his cigar lit and burning satisfactorily, he listened to a radio program broadcast from Earth.