Roy remembered what he had come for. “You’re two days past dinnertime. I thought I’d—”

“Not hungry. My prism’s in the oven, and I’ve got to wait for it to cool.”

“I could bring—”

“No thanks.”

“Any significance?”

“Didn’t I tell you I was predictable? If there aren’t any Pak scouts in the vicinity, you could just as well go on to Wunderland alone. Most of what I know about the Pak is stored in the computer. When a protector feels not needed, he doesn’t eat.”

“So you’re kind of hoping we find Pak scouts.”

Brennan laughed: a credible chuckle, though his mouth didn’t move. His face wasn’t hard, exactly; it was like wrinkled leather. It was his mouth that was like hard shell. Too much of human expression is in the mouth.

On the evening of the same day he came out towing three hundred pounds of machinery, of which a big, solid crystal prism was a prominent part. He wouldn’t let Roy help tow it, but they set it up together at the focus of the Flying Dutchman’s telescope. Roy brought him a sandwich then, and made him eat it. The Jewish mother role irritated him, but so did the thought of going on to Wunderland alone.

Brennan was gone when Roy came looking for him, around mid-afternoon of the fifth day. Roy found him in the one room from which he was forbidden, the hydroponics garden. Brennan was moving down the side of an open tank, consuming sweet potatoes one after another.

The prism threw a rainbow spectrum across a white surface. Brennan pointed to a bright green line. “Beryllium light, blue-shifted,” he said. “And the helium lines are up in the violet. Ordinarily beryllium is in the infrared.”

“Blue-shifted.” Any school child knew what that meant. “He’s coming down our throats.”

“Maybe not. He’s coming toward us, but maybe not dead on. We’re only a couple of light-weeks out from Sol, and he’s a light-year away, and I think he’s decelerating. I’ll have to check to see if we’re getting his exhaust. But I think he’s headed for Sol.”

“Brennan, that’s worse.”

“It’s just as bad as it can get. We’ll know in a month. He’ll have moved by then. We’ll have some paralax on him.”

“A month! But—”

“Just a minute. Calm down. How far can be go in a month? He’s way below lightspeed; we’re probably going faster than he is. A month won’t cost us much — and I’ve got to know how many there are, and where they are, and where they’re going. And I’ve got to build something.”

“What?”

“A widget. Something I dreamed up after we found the Pak fleet, when I saw that there might be Pak scouts around. The designs are in the computer.”

Roy did not fear loneliness. He feared its opposite. Brennan was an odd companion, and Protector was going to be cramped when they finally left the Flying Dutchman. For a week or so Roy stayed away from the observatory, consciously savoring his alone-ness. In the empty exercise room he hovered in midair, swinging his arms and legs in wide circles. Later he would want to remember the room. Even this half-hollowed ball of rock was too small for a man who would rather be climbing a mountain.

Once he suggested another dry run. Brennan’s models of the Pak scouts would be more accurate now. But Brennan wasn’t having any. “You know as much as you’re ever going to about fighting Pak. Does that scare you?”

“Hell, yes.”

“Glad to bear it.”

One day Brennan wasn’t in the laboratory. Roy went looking for him. The longer it took the more stubborn he got; but Brennan didn’t seem to be anywhere aboard.

He finally asked himself, “How would Brennan handle this? Logic. If he’s not inside, then he’s outside. What’s outside that he might need?”

Right. Vacuum, and access to the surface.

The tree, the grass, the mud of the pond bottom were all freeze-dried and dead. The stars were bright and eerie, and more real than they had seemed on a vision screen. Roy could see them as a battlefield: the unseen worlds as territories to be fought over, the gas shells around stars as death traps for an unwary warrior.

He spotted Brennan’s torch.

Brennan was working in vacuum, building… something. His redesigned pressure suit seemed both alien and anachronistic, and the chest design was a detail from Dali: a Madonna and Child, very beautiful. A torn loaf of bread floated within the window in the Child’s torso, and he looked down at it with an adult, thoughtful gaze.

“Don’t come too close,” Brennan said into his suit mike. “I had plenty of time to fiddle with this ball of rock while I was shaping Kobold. There are deposits of pure elements under all this landscaping.”

“What are you making?”

“Something that should collapse a polarized gravity generator at a distance. If generated gravity is what they’re using to hold their ships in tandem, they’ll have to polarize it to make it work over those distances. We know they know how to do it. They’ll put the generator on the trailing ship, because that’s the ship that’s producing enough excess power to maintain the field.”

“Suppose they’re using something else?”

“So I waste a month. But I won’t believe they’re using cables. In deceleration mode even a Pak cable won’t stand up to the exhaust from the trailing ship. I might believe they loaded everything on the trailing ship and used the lead ship purely as a stripped Bussard ramjet compressor. But they’d lose power and maneuverability.

“I’ve been trying to design a Pak scout ship myself. It isn’t easy, because I don’t know what they’ve got. The worst thing I can think of from our viewpoint is two independent ships with heavy, versatile ram field generators. That way if you lost a couple of lead ships in a battle, you could link the trailing ships, and vice versa.”

“Yah.”

“But I don’t believe it. The more widgetry they put into each ship, the fewer ships they wind up with. I think they’d compromise. The lead ship is a Bussard ramjet, built to fight, but not too different from ours. It’s the trailing ship that’s versatile, with the oversized adjustable ram field generator. You could link two trailing ships, but not two lead ships. The lead ships are more vulnerable anyway. You saw that.”

“Then these scouts are tougher than what I fought.”

“And there are three of them.”

“Three.”

“They’re coming in a cone, through — you remember that map of the space around Sol? There’s a region that’s almost all red dwarfs, and they’re coming through that. I think the idea is to map an escape route for the fleet, in case something goes wrong at Sol. Otherwise they’ll see to it that Sol is clean, then go on to other yellow dwarf stars. At the moment they’re all about a light year from Sol and about eight light-months apart.”

Roy looked up. Where within the battlefield — ? He found Sol easily, but he couldn’t remember the direction of the first scout. He shivered in his suit, though it was far more comfortable than it had ever been. Brennan had been tinkering with it.

“There could be more.”

“I doubt it,” said Brennan. “I didn’t find any more beryllium traces at any frequency shift.”

“Suppose they came in ones instead of twos. They’d show as ordinary Bussard ships.”

“I don’t believe it. Look, they need to be able to see each other. If a scout disappears, the others want to know it.”

“All right. Now we’ve got to keep them away from Sol. How about using ourselves as a decoy?”

“Right.”

That absent-minded monosyllable was disconcerting. It happened every so often, this implication that Brennan had already thought it through, in every detail, long ago. When he didn’t say any more, Roy asked, “Anything I can do to help?”

“No. I’ve got to finish this. Improve your mind. Brush up on local astronomy; it’s our battle map. Look up Home. We’re not going to Wunderland now. We’re going to Home, if we get the choice.”