David Unger wiped his mouth on his sleeve, then lay back weakly against his chair. "I don't know," he repeated, his voice faint and dry. "I told you I don't remember any more. It was so long ago."

Gannet signaled, and the officers moved away from the old man. "It's coming," he said wearily. He mopped his perspiring forehead. "Slowly and surely. We should have what we want inside another half hour."

One side of the therapy house had been turned into a Military table-map. Counters had been laid out across the surface to represent units of the web-foot and crow fleets. White luminous chips represented Earth ships lined up against them in a tight ring around the third planet.

"It's someplace near here," Lieutenant West said to Patterson. Red-eyed, stubble-chinned, hands shaking with fatigue and tension, he indicated a sec­tion of the map. "Unger remembers hearing officers talking about this con­voy. The convoy took off from a supply base on Ganymede. It disappeared on some kind of deliberate random course." His hands swept the area. "At the time, nobody on Earth paid any attention to it. Later, they realized what they'd lost. Some military expert charted the thing in retrospect and it was taped and passed around. Officers got together and analyzed the incident. Unger thinks the convoy route took it close to Europa. But maybe it was Callisto."

"That's not good enough," Gannet snapped. "So far we don't have any more route data than Earth tacticians had at that time. We need to add exact knowledge, material released after the event."

David Unger fumbled with a glass of water. "Thanks," he muttered grate­fully, as one of the young officers handed it to him. "I sure wish I could help you fellows out better," he said plaintively. "I'm trying to remember. But I don't seem able to think clear, like I used to." His wizened face twisted with futile concentration. "You know, it seems to me that convoy was stopped near Mars by some kind of meteor swarm."

Gannet moved forward. "Go on."

Unger appealed to him pathetically. "I want to help you all I can, mister. Most people go to write a book about a war, they just scan stuff from other books." There was a pitiful gratitude on the eroded face. "I guess you'll mention my name in your book, someplace."

"Sure," Gannet said expansively. "Your name'll be on the first page. Maybe we could even get in a picture of you."

"I know all about the war," Unger muttered. "Give me time and I'll have it straight. Just give me time. I'm trying as best I can."

The old man was deteriorating rapidly. His wrinkled face was an unhealthy gray. Like drying putty, his flesh clung to his brittle, yellowed bones. His breath rattled in his throat. It was obvious to everyone present that David Unger was going to die -- and soon.

"If he croaks before he remembers," Gannet said softly to Lieutenant West, "I'll --"

"What's that?" Unger asked sharply. His one good eye was suddenly keen and wary. "I can't hear so good."

"Just fill in the missing elements,"Gannet said wearily. He jerked his head. "Get him over to the map where he can see the setup. Maybe that'll help."

The old man was yanked to his feet and propelled to the table. Technicians and brass hats closed in around him and the dim-eyed stumbling figure was lost from sight.

"He won't last long," Patterson said savagely. "If you don't let him rest his heart's going to give out."

"We must have the information," Gannet retorted. He eyed Patterson. "Where's the other doctor? LeMarr, I think he's called."

Patterson glanced briefly around. "I don't see him. He probably couldn't stand it."

"LeMarr never came," Gannet said, without emotion. "I wonder if we should have somebody round him up." He indicated Evelyn Cutter, who had just arrived, white-faced, her black eyes wide, breathing quickly. "She suggests --"

"It doesn't matter now," Evelyn said frigidly. She shot a quick, urgent glance at Patterson. "I want nothing to do with you and your war."

Gannet shrugged. "I'll send out a routine net, in any case. Just to be on the safe side." He moved off, leaving Evelyn and Patterson standing alone together.

"Listen to me," Evelyn said harshly, her lips hot and close to his ear. "Unger's number has come up."

"When did they notify you?" Patterson demanded.

"I was on my way here. I did what you said -- I fixed it up with a clerk at Military."

"How long ago?"

"Just now." Evelyn's face trembled. "Vachel, he's here"

It was a moment before Patterson understood. "You mean they sent him over here? To the hospital?"

"I told them to. I told them when he came to volunteer, when his number came to the top --"

Patterson grabbed her and hurried her from the therapy house, outside into the bright sunlight. He pushed her onto an ascent ramp and crowded in after her. "Where are they holding him?"

"In the public reception room. They told him it was a routine physical check. A minor test of some kind." Evelyn was terrified. "What are we going to do? Can we do something?"

"Gannet thinks so."

"Suppose we -- stopped him? Maybe we could turn him aside?" She shook her head, dazed. "What would happen? What would the future be like if we stopped him here? You could keep him out of the Service -- you're a doc­tor. A little red check on his health card." She began to laugh wildly. "I see them all the time. A little red check, and no more David Unger. Gannet never sees him, Gannet never knows Earth can't win and then Earth will win, and V-Stephens doesn't get locked up as a psychotic and that webfoot girl --"

Patterson's open hand smashed across the woman's face. "Shut up and snap out of it! We don't have time for that!"

Evelyn shuddered; he caught hold of her and held on tight to her until finally she raised her face. A red welt was rising slowly on her cheek. "I'm sorry," she managed to murmur. "Thanks. I'll be all right."

The lift had reached the main floor. The door slid back and Patterson led her out into the hall. "You haven't seen him?"

"No. When they told me the number had come up and he was on his way" -- Evelyn hurried breathlessly after Patterson -- "I came as quickly as I could. Maybe it's too late. Maybe he got tired of waiting and left. He's a fifteen year old boy. He wants to get into the fight. Maybe he's gone!"

Patterson halted a robot attendant. "Are you busy?"

"No sir," the robot answered.

Patterson gave the robot David Unger's i.d. number. "Get this man from the main reception room. Send him out here and then close off this hall. Seal it at both ends so nobody can enter or leave."

The robot clicked uncertainly. "Will there be further orders? This syn­drome doesn't complete a --"

"I'll instruct you later. Make sure nobody comes out with him. I want to meet him here alone."

The robot scanned the number and then disappeared into the reception room.

Patterson gripped Evelyn's arm. "Scared?"

"I'm terrified."

"I'll handle it. You just stand there." He passed her his cigarettes. "Light one for both of us."

"Three, maybe. One for Unger."

Patterson grinned. "He's too young, remember? He's not old enough to smoke."

The robot returned. With it was a blond boy, plump and blue-eyed, his face wrinkled with perplexity. "You wanted me, Doc?" He came uncertainly up to Patterson. "Is there something wrong with me? They told me to come here, but they didn't say what for." His anxiety increased with a tidal rush. "There's nothing to keep me out of the Service is there?"

Patterson grabbed the boy's newly stamped i.d. card, glanced at it, and then passed it to Evelyn. She accepted it with paralyzed fingers, her eyes on the blond youth.

He was not David Unger.

"What's your name?" Patterson demanded.