you're sick, let me take you to a doctor."

Briscoe did not even hear. "Wait, there is something else. Your father said, 'Tell Bart I've gone looking for the Eighth Color. Bart will know what I mean.'"

"That's crazy. I don't know—"

He broke off, for the memory had come, full-blown:

He was very young: five, six, seven. His mother, tall and slender and very fair, was bending over a blueprint, pointing with a delicate finger at something, straightening, saying in her light musical voice:

"The fuel catalyst—it's a strange color, a color you never saw anywhere. Can you think of a color that isn't red, orange, yellow, green, blue, violet, indigo or some combination of them? It isn't any of the colors of the spectrum at all. The fuel is a real eighth color."

And his father had used the phrase, almost adopted it. "When we know what the eighth color is, we'll have the secret of the star-drive, too!"

Briscoe saw his face change, nodded weakly. "I see it means something to you. Now will you do as I tell you? Within a couple of hours, they'll be combing the planet for you, but by that time the ship I came in on will have taken off again. They only stop a short time here, for mail, passengers—no cargo. They may get under way again before all messages are cleared and decoded." He stopped and breathed hard. "The Earth authorities might protect you, but you would never be able to board a Lhari ship again—and that would mean staying on Earth for the rest of your life. You've got to get away before they start comparing notes. Here." His hand went into his pockets. "For your hair. It's a dye—a spray."

He pressed a button on the bulb in his hand; Bart gasped, feeling cold wetness on his head. His own hand came away stained black.

"Keep still." Briscoe said irritably. "You'll need it at the Procyon end of the run. Here." He stuck some papers into Bart's hand, then punched some buttons on the robotcab's control. It wheeled and swerved so rapidly that Bart fell against the fat man's shoulder.

"Are you crazy? What are you going to do?"

Briscoe looked straight into Bart's eyes. In his hoarse, sick voice, he said, "Bart, don't worry about me. It's all over for me, whatever happens. Just remember this. What your father is doing is worth doing, and if you start stalling, arguing, demanding explanations, you can foul up a hundred people—and kill about half of them."

He closed Bart's fingers roughly over the papers. The robotcab hovered over the spaceport. "Now listen to me, very carefully. When I stop the cab, down below, jump out. Don't stop to say good-bye, or ask questions, or anything else. Just get out, walk straight through the passenger door and straight up the ramp of the ship. Show them that ticket, and get on. Whatever happens, don't let anything stop you. Bart!" Briscoe shook his shoulder. "Promise! Whatever happens, you'll get on that ship!"

Bart swallowed, feeling as if he'd been shoved into a silly cops-and-robbers game. But Briscoe's urgency had convinced him. "Where am I going?"

"All I have is a name—Raynor Three," Briscoe said, "and the message about the Eighth Color. That's all I know." His mouth twisted again in that painful gasp.

The cab swooped down. Bart found his voice. "But what then? Is Dad there? Will I know—"

"I don't know any more than I've told you," Briscoe said. Abruptly the robotcab came to a halt, swaying a little. Briscoe jerked the door open, gave Bart a push, and Bart found himself stumbling out on the ramp beside the spaceport building. He caught his balance, looked around, and realized that the robotcab was already climbing the sky again.

Immediately before him, neon letters spelled TO PASSENGER ENTRANCE ONLY. Bart stumbled forward. The Lhari by the gate thrust out a disinterested claw. Bart held up what Briscoe had shoved into his hand, only now seeing that it was a thin wallet, a set of identity papers and a strip of pink tickets.

"Procyon Alpha. Corridor B, straight through." The Lhari gestured, and Bart went through the narrow passageway, came out at the other end, and found himself at the very base of a curving stair that led up and up toward a door in the side of the huge Lhari ship. Bart hesitated. In another minute he'd be on his way to a strange sun and a strange world, on what might well be the wild-goose chase of all time.

Passengers were crowding the steps behind him. Someone shouted suddenly, "Look at that!" and someone else yelled, "Is that guy crazy?"

Bart looked up. A robotcab was swooping over the spaceport in wild, crazy circles, dipping down, suddenly making a dart like an enraged wasp at a little nest of Lhari. They ducked and scattered; the robotcab swerved away, hovered, swooped back. This time it struck one of the Lhari grazingly with landing gear and knocked him sprawling. Bart stood with his mouth open, as if paralyzed.

Briscoe! What was he doing?

The fallen Lhari lay without moving. The robotcab moved in again, as if for the kill, buzzing viciously overhead.

Then a beam of light arced from one of the drawn energon-ray tubes. The robotcab glowed briefly red, then seemed to sag, sink together; then puddled, a slag heap of molten metal, on the glassy floor of the port. A little moan of horror came from the crowd, and Bart felt a sudden, wrenching sickness. It had been like a game, a silly game of cops and robbers, and suddenly it was as serious as melted death lying there on the spaceport. Briscoe!

Someone shoved him and said, "Come on, quit gawking, kid. They won't hold the ship all day just because some nut finds a new way to commit suicide."

Bart, his legs numb, walked up the ramp. Briscoe had died to give him this chance. Now it was up to him to make it worth having.

CHAPTER THREE

At the top of the ramp, a Lhari glanced briefly at his papers, motioned him through. Bart passed through the airlock, and into a brightly lit corridor half full of passengers. The line was moving slowly, and for the first time Bart had a chance to think.

He had never seen violent death before. In this civilized world, you didn't. He knew if he thought about Briscoe, he'd start bawling like a baby, so he swallowed hard a couple of times, set his chin, and concentrated on the trip to Procyon Alpha. That meant this ship was outbound on the Aldebaran run—Proxima Centauri, Sirius, Pollux, Procyon, Capella and Aldebaran.

The line of passengers was disappearing through a doorway. A woman ahead of Bart turned and said nervously, "We won't be put into cold-sleep right away, will we?"

He reassured her, remembering his inbound trip five years ago. "No, no. The ship won't go into warp-drive until we're well past Pluto. It will be several days, at least."

Beyond the doorway the lights dwindled, and a Mentorian interpreter took his dark glasses, saying, "Kindly remove your belt, shoes and other accessories of leather or metal before stepping into the decontamination chamber. They will be separately decontaminated and returned to you. Papers, please."

With a small twinge of fright, Bart surrendered them. Would the Mentorian ask why he was carrying two wallets? Inside the other one, he still had his Academy ID card which identified him as Bart Steele, and if the Mentorian looked through them to check, and found out he was carrying two sets of identity papers....

But the Mentorian merely dumped all his pocket paraphernalia, without looking at it, into a sack. "Just step through here."

Holding up his trousers with both hands, Bart stepped inside the indicated cubicle. It was filled with faint bluish light. Bart felt a strong tingling and a faint electrical smell, and along his forearms there was a slight prickling where the small hairs were all standing on end. He knew that the invisible R-rays were killing all the microorganisms in his