Ray slammed the main star drive switch clear over. There was no feeling of acceleration. They were suddenly floating weightless and Jupiter whizzed past the forward port. "Stop!" howled the Jovian. The engine throbbed and sang, energy pulsing in great waves through its shuddering substance. The stars crawled eerily across the ports. "Aberration," gasped Ray. "We're approaching the speed of light." Space swam and blazed with a million million suns. They bunched near the forward port, thinning out toward the rear, as the ship added its fantastic velocity vector to their light-rays. A distorted pale-green globe grew rapidly before the vessel. "Vat planet is that up ahead?" pointed Dyann. "I think--" muttered Ray. He looked out the rearward port. "I think it was Neptune." "Triumph!" chortled Urushkidan, rubbing his tentacles together. "My teory is confirmed. Not tat it needs confirmation, but now even an Eartman can see tat I am always right. And oh, how tey'll habe to pay!" The colors of the stars shifted toward blue in front and red behind. Doppler effect, thought Ray wildly. He was probably seeing by radio waves and gamma rays now. How fast were they going, anyway? He should have thought to install some kind of speed gauge. Several times the velocity of light at least. "Ha, this is fun," laughed Dyann. "Hmmm--we better stop while we can still see the Solar System," said Ray, and cut the main drive. The ship kept on going. "Hey!" screamed the Earthling. "Stop! Whoa!" "We can't stop," said Urushkidan coolly. "We're in a certain pseudobelocity-state now. Te engine merely accelerates us." "Well, how in hell do you brake?" groaned Ray. "I don't know. We'll habe to figure tat out. I tought you knew tis would happen." "Now I do." Ray floated free of his chair, beating his forehead with his fists. "I hope to heaven we can do it before the food runs out." Dyann looked at Urushkidan speculatively. "If vorst comes to vorst," she murmured, "roast Martian--" "Let's get busy," gasped Urushkidan. * * * * * It took a week to improvise a braking system. By that time they were no longer very sure where they were. "This is all my fault," said Dyann contritely. "If I had brought Ormun along she vould have looked after us." "One thing that worries me," said Ray, "is the Jovians. They aren't fools, and they won't be sitting on their hands waiting for us to come back and give the star drive to Earth." "First," said Urushkidan snappishly, "tere is te problem of finding our sun." Ray looked out the port. The ship was braked and, in the normal space-time state of matter, was floating amidst a wilderness of unfamiliar constellations. "It shouldn't be too hard," he said thoughtfully. "Look, there are the Magellanic Clouds, I think, and we should be able to locate Rigel or some other bright star. That way we can get a fix and locate ourselves relative to Sol."