There was a flash of sun-bright flame very, very far away. There was a little cloud of vapor which dissipated swiftly. Then there was nothing but two or three specks moving at random, their target lost, their purpose forgotten. The fact of victory was an anticlimax. "All clear," said Bors grimly. The inner-compartment doors opened. The normal sounds of the ship were heard again. Bors began to calculate the data needed for the journey to Garen. There was the angle and the distance and the proper motions and the time elapsed.... He found it difficult to think in such terms. He was discontented. He'd ambushed a Mekinese cruiser. True, he'd let his own ship be seen, and the Mekinese had warning enough to launch missiles in their own defense. It was not even faintly like the ambush of a cruiser on the bottom of a Kandarian sea, waiting to assassinate a fleet when its complement went on board. But Bors didn't like what he'd just done. The figures wouldn't come out right. Impatiently, he sent for Logan. The mathematical Talent came into the control room. "Will you calculate this for me?" Bors asked irritably. Logan glanced casually at the figures and wrote down the answer. Instantly. Without thought or reflection. Instantly! Bors couldn't quite believe it. The distance between the two stars was a rounded-off number, of course. The relative proper motion of the two stars had a large plus-or-minus bugger factor. The time-lapse due to distance had a presumed correction and there was a considerable probable error in the speed of translation of the ship during overdrive. It was a moderately complicated equation, and the computation of the probable error was especially tricky. Bors stared at it, and then stared at Logan. "That's the answer to what you have written there," said Logan condescendingly, "but your figures are off. I've been talking to your computer men. They've given me the log figures on past overdrive jumps and the observed errors on arrival. They're systematic. I noticed it at once." Bors said, "What?" "There's a source of consistent error," Logan said patiently. "I found the values to correct it, then I found the source. It's in your overdrive speed." Bors blinked. Speed in overdrive could not be computed exactly. The approximation was very close--within a fraction of a tenth of one per cent--but when the distance traveled was light-years the uncertainty piled up. "If you use these figures," said Logan complacently--and he scribbled figures swiftly--"you'll get it really accurate." Having finished writing the equation, he wrote the solution. Bors asked suspicious questions. Logan answered absently. He knew nothing about overdrive. He didn't understand anything but numbers and he didn't know how he did what he did with them. But he'd worked backward from observed errors in calculation and found a way to keep them out of the answer. And he'd done it all in his head. It was unbelievable--yet Bors believed.