"How long have you been standing by like this?" asked Horn, professionally.
The ratty little man said, "Thirty-six hours," in a hopeless voice.
"Since before the landing on Formalhaut," observed Horn. "You're pretty tired. All right. I'm relieving you."
"But-but -"
"You'll be missing the cycle breaks presently," said Horn, "because you'll be too tired to catch them. When you miss one, everything will blow. Get up!"
The little man got up, apprehensively. Horn took his place.
"Tell the cook to send me some coffee," he commanded, "and then get some sleep. Not too much! You'll have to take over again."
The engineer shook visibly. He was frightened, but also he was exhausted. He was in a state where he was liable to commit errors from pure fatigue. He said desperately, "But the skipper -"
"The skipper got me on board to tinker with the engines," said Horn. "It's all right. You get the cook to send me some coffee, and get some rest. Then come back."
Trembling, the engineer went away. Then Horn examined the engines. In the process of training to become a designer of space drives, he'd necessarily learned the history of space engines. He'd absorbed the facts of life about earlier varieties, from those primitive rockets with which men accomplished the incredible, to the Dirac drive which carried the first interstellar ship from one solar system to another. And since Riccardo engines had contained the germs of modern drives, Horn had learned their eccentricities in the process of coming to understand current drives which didn't have drawbacks.
He muttered to himself as he inspected the Theban's engines. There'd been a complete, functioning Riccardo drive where he'd had his technical training. He could compare this seemingly disintegrating mass of patches on patches with his memory of how such a drive had been in the beginning. He could see what had happened. There'd been a series of owners and engineers of the Theban. There were repairs, some done decently and with thoroughness; those were early ones. But there were some that were strictly emergency repairs, never properly replaced by other than emergency materials. They weren't altogether right, and they had side effects producing new emergencies, and these had side effects too. In effect, to Horn the Theban's engines looked as if they'd been mended with strings and glue and the mendings were beginning to fall apart.
Swearing to himself, he did a trivial something here and something else there. One unstable patching job became a little more stable. He reworked an especially perilous temporary repair that should have been replaced at the first possible spaceport. There was a place where two wires at some past time had arced and broken, and the severed ends simply twisted together without even a plastic conductor between them. It appeared miraculous that none of these inadequate patchings had failed before now. The Theban couldn't have had a real engine overhaul in decades.
Presently the red-haired mate came down the companion ladder from the control room. He saw Horn at the engines, and his jaw dropped. He climbed hastily back up to the control room. Seconds later he reappeared with Larsen, the skipper. Horn nodded absent-mindedly at them. It was the one reaction neither of the two could have imagined beforehand. Horn at the engines could be a guarantee of temporary survival. But on the other hand -
"What're you doing there?" growled Larsen.
"I relieved the engineer," said Horn. "He was about to crack up from lack of sleep."
"Lack of liquor, most likely," growled Larsen. "You've got the engines running right?"
"Listen to them," said Horn gently. "Do they sound right? No. I haven't patched them up. I'm finding out what's wrong with them. And I'm waiting for a deal."
He didn't refer to the combat in the control room. Larsen looked malevolent. The red-haired mate looked vengeful but scared. They were in a situation they hadn't planned. Horn had given proof that he wasn't an ordinary, terrifyable sort of man. If he could be scared, he might have been browbeaten into obeying orders. But it was explicit in his behaviour that he could not be cowed. He was a prisoner on the Theban, but in a sense the Theban was at his mercy. He might be forced to make repairs, but only he could tell whether they were repairs or not. The Theban's own engineer couldn't tell. So threats to Horn could mean only so much. But if he repaired the engines permanently, his captors would have no reason not to kill him, and motives of prudence to do so. So it wasn't likely he'd get the engines far from the edge of disaster. He had to be placated and kept placated - but he'd know his captors would never quite dare to release him. It wasn't an easily resolvable problem.
Larsen swore.
"What'd d'you mean a deal? What kind of deal?"
"You figure one out," said Horn pleasantly, "and I'll listen to it. You want this scrapheap fixed up. I suppose you've something specific in mind, or you'd have stayed aground on Formalhaut for repairs. But you didn't. I can make these engines stagger along for a strictly limited length of time. So far I haven't done that, and I won't unless I have reason to. I want to get off this ship and you want it in good working order. You figure out a deal that will satisfy both of us, and I'll listen to it."
Larsen's face grew purple. Horn's infuriating assumption that terms must be made with him - and the fact that he had a good argument - reignited his burning fury over the battle in the control room and its unsatisfying conclusion. He took one step towards Horn.
Horn did something Larsen didn't see. The moaning sound of the engines rose in pitch and volume until it was like a shriek. Then Horn made gestures, and seemingly agitated adjustments, while the purplish tint of Larsen's face faded to a sickly pallor. The red-headed mate made an indecisive movement as if about to wring his hands.
Finally Horn appeared to get the cause of the noise in hand. With an air of complete, tense absorption, he shifted controls. The shriek decreased in loudness and then went down in pitch, and presently the sound of the engines was almost what it had been before. But there was a new, warbling, burbling sound added to what had been heard before.
Horn wiped off his forehead as if it were wet with sudden cold sweat. Larsen and the red- haired mate stood frozen in their tracks.
"That," said Horn, "was close! I really think you'd better get this ship aground somewhere and let me do a little real work on those engines. And while you're doing that, you might figure out a deal to justify my helping you."
He nodded, but again seemed to wipe sweat off his face. Then he added, "And you might tell the cook to send me some coffee."
He leaned back in his seat with an air of vigilance, seeming to pay no more attention to the two at the foot of the companion ladder. Instead, he frowningly listened to the slightly changed noise of the engines.
Larsen muttered to the mate, then turned and went back up to the control room. The mate went below to the galley. Horn did not turn his head.
A little later the cook came up with coffee. There was also a plate with food on it. Horn accepted it abstractedly. The cook said uneasily, "That noise just now - what happened?"
"We almost had it," said Horn, "but I caught it in time. These engines are in horrible shape! Running them anywhere except to a repair shop is just plain crazy."
The cook licked his lips. There'd been space travel for a long, long while now, but there were still cases of ships vanishing in space. Between spaceports the distance might be only days of journeying in overdrive, but in miles it was billions or trillions. And a ship which became helpless in space through the failure of its engines couldn't even hope to be found again. Its crew were dead the instant the failure occurred, though they might move about and go mad from despair.
Or they could take to the boats, of course. But that wasn't necessarily much better. Lifeboats didn't carry enough air for space journeys of indefinite length. Or enough fuel, either.