Matt caught s.n.a.t.c.hes of conversation as they pushed their way across the room. The party hadn't been going long, he gathered, and several people knew practically n.o.body; but they all had drinks. They were of all ages, all professions. Hood had spoken true. If a party crasher wasn't welcome, he'd never know it, because no one would recognize him as one.

The walls were like the outside, a glowing coral pink. The floor, covered with a hairy-looking wall-to-wall rug of mutated gra.s.s, was flat except at the walls; no doubt it had been sanded fiat after the house was finished and the forming balloon removed.

A visit from a crew always upset Jesus Pietro's men.

At least Parlette had come to him. Once Parlette had summoned him to his own house, and that had been bad. Here, Jesus Pietro was in his element. His office was practically an extension of his personality. The desk had the shape of a boomerang, enclosing him in an obtuse angle for more available working s.p.a.ce. He had three guests' chairs of varying degrees of comfort, for crew and Hospital personnel and colonist. The office was big and square, but there was a slight curve to the back wall. Where the other walls were cream colored, easy on the eye, the back wall was smoothly polished dark metal.

It was part of the outer hull of the Planck. Planck. Jesus Pietro's office was right up against the source of half the spiritual strength of Mount Lookitthat, and half the electrical power too: the ship that had brought men to this world. Sitting at his desk, Jesus Pietro felt the power at his back. Jesus Pietro's office was right up against the source of half the spiritual strength of Mount Lookitthat, and half the electrical power too: the ship that had brought men to this world. Sitting at his desk, Jesus Pietro felt the power at his back.

An officer had found the housecleaner nest, a niche in the south wall, near the floor. The man reached in and carefully removed two unconscious adult housecleaners and four pups, put them on the floor, reached in to remove the nest and the food dish. The niche would have to be searched.

Jesus Pietro's clothes dried slowly, in wrinkles. He sat with his eyes closed and his hands folded on his belly. Presently he opened his eyes, sighed, and frowned slightly.

-Jesus Pietro, this is a very strange house.

-Yes. Almost garishly colonist. (Overtones of disgust.) (Overtones of disgust.) Jesus Pietro looked at the pink coral walls, the flat-sanded floor which curved up at the edge of the rug to join the walls. Not a bad effect if a woman were living here. But Harry Kane was a bachelor.

-How much would you say a house like this cost?

-Oh, about a thousand stars, not including furnishings. Furnishings would cost twice that. Rugs, ninety stars if you bought one and let it spread. Two housecleaners, mated, fifty stars.

-And how much to put a bas.e.m.e.nt under such a house?

-Mist Demons, what an idea! Bas.e.m.e.nts have to be dug by hand, by human beings! It'd cost twenty thousand stars easily. You could build a school for that. Who would ever think of digging a bas.e.m.e.nt under an architectural coral house?

-Who indeed?

Jesus Pietro stepped briskly to the door. "Major Jansen!"

Geologists (don't (don't give me a hard time about that word) believed that Mount Lookitthat was geologically recent. A few hundreds of thousands of years ago, part of the planet's skin had turned molten. Possibly a convection current in the interior had carried more than ordinarily hot magma up to melt the surface; possibly an asteroid had died a violent, fiery death. A slow extrusion had followed, with viscous magma rising and cooling and rising and cooling until a plateau with fluted sides and an approximately flat top stood forty miles above the surface. give me a hard time about that word) believed that Mount Lookitthat was geologically recent. A few hundreds of thousands of years ago, part of the planet's skin had turned molten. Possibly a convection current in the interior had carried more than ordinarily hot magma up to melt the surface; possibly an asteroid had died a violent, fiery death. A slow extrusion had followed, with viscous magma rising and cooling and rising and cooling until a plateau with fluted sides and an approximately flat top stood forty miles above the surface.

It had to be recent. Such a preposterous anomaly could not long resist the erosion of Mount Lookitthat's atmosphere.

And because it was recent, the surface was 'jagged, Generally the northern end was higher, high enough to hold a permanent sliding glacier, and too high and too cold for comfort. Generally rivers and streams ran south, to join either the Muddy or the Long Fall, both of which had carved deep canyons for themselves through the southland. Both canyons ended in spectacular waterfalls. the tallest in the known universe. Generally the rivers ran south; but there were exceptions, for the surface of Mount Lookitthat was striated, differentiated, a maze of plateaus divided by cliffs and chasms.

Some plateaus were flat; some of the cliffs were straight and vertical. Most of these were in the south. In the north the surface was all tilted blocks and strange lakes with deep, pointed bottoms, and the land would have been cruel to a mountain goat. Nonetheless these regions would be settled someday, just as the Rocky Mountains of Earth were now part of suburbia.

The s...o...b..ats had landed in the south, on the highest plateau around. The colonists had been forced to settle lower down. Though they were the more numerous, they covered less territory, for the crew had cars, and flying cars can make a distant mountain-home satisfactory where bicycles will not. Yet Alpha Plateau was Crew Plateau, and for many it was better to live elbow to elbow with one's peers than out in the boondocks in splendid isolation.

So Alpha Plateau was crowded.

What Mart saw below him were all houses. They varied enormously in size, in color, in style, in building material. To Matt, who had lived out his life in architectural coral, the dwellings looked like sheer havoc, like debris from the explosion of a time machine. There was even a clump of deserted, crumbling coral bungalows, each far bigger than a colonist's home. Two or three were as large as Matt's old grade school. When architectural coral first came to the Plateau, the crew had reserved it for their own use. Later it had gone permanently out of style.

None of the nearby buildings seemed to be more than two stories tall. Someday there would be skysc.r.a.pers if the crew kept breeding. But in the distance two squat towers rose from a shapeless construction in stone and metal. The Hospital, without a doubt. And straight ahead.

Mart was beginning to feel the strain of flying. He had to divide his attention between the dashboard, the ground, and the Hospital ahead. It was coming closer, and he was beginning to appreciate its size.

Each of the empty s...o...b..ats had been built to house six crew in adequate comfort and fifty colonists in stasis. Each s...o...b..at also included a cargo hold, two water-fueled reaction motors and a water fuel tank. And all of this had to be fitted into a hollow double-walled cylinder the shape of a beer can from which the top and bottom have been removed with a can opener. The s...o...b..ats had been circular flying wings. In transit between worlds they had spun on their axes to provide centrifugal gravity; and the empty s.p.a.ce inside the inner hull, now occupied only by two intersecting tailfins, had once held two throwaway hydrogen balloons.

They were big. Since Mart could not see the inner emptiness which the crew called the Attic, they looked far bigger. Yet they were swamped by the haphazard-looking stone construction of the Hospital. Most of it was two stories high, but there were towers which climbed halfway up the ships' hulls. Some would be power stations, others-he couldn't guess. Flat, barren rock surrounded the Hospital in a half-mile circle, rock as naked as the Plateau had been before the s...o...b..ats brought a carefully selected ecology.

"Mart!" Laney called over her shoulder. She was standing inches from the void.

"Get back from there!"

"No! Come here!"

Mart went. So did Mrs. Hanc.o.c.k. The three of them stood at the edge of the gra.s.s, looking down into their shadows.

The sun was at their backs, shining down at forty-five degrees. The water-vapor mist which had covered the southern end of the Plateau that morning now lay just beyond the void edge, almost at their feet. And they looked into their shadows-three shadows reaching down into infinity, three contoured black tunnels growing smaller and narrower as they bored through the lighted mist, until they reached their blurred vanishing points. But for each of the three it seemed that only his own shadow was surrounded by a small, vivid, perfectly circular rainbow.

A fourth shadow joined them, moving slowly and painfully. "Oh, for a camera," mourned Harry Kane.

"I never saw it like that before," said Matt.

"I did, once, a long time ago. It was like I'd had a vision. Myself, the representative of Man, standing at the edge of the world with a rainbow about his head. I joined the Sons of Earth that night."

Orson popped open one of the cans, drank, and made a face at Snow Goose. "You brought me all the way to h.e.l.l for sugar-free 7-Up?" sugar-free 7-Up?"

THE BARSOOM PROJECT, 1989.

FOR A FOGGY NIGHT.

This is the story story Jerry Pournelle quotes to demonstrate why he writes with me. I'm the crazy one. Jerry Pournelle quotes to demonstrate why he writes with me. I'm the crazy one.

He comes to me with a map of a city-sized building; I put a put a high diving board at The edge of the roof. I put a surfer on a tidal wave in LUCIFER'S high diving board at The edge of the roof. I put a surfer on a tidal wave in LUCIFER'S HAMMER; HAMMER; he moves the beach to where it would work. Jerry puts High Frontier weapons in the grip of the invading ftfhp, but mine is the vision of baby elephants in tennis shoes gliding out of the he moves the beach to where it would work. Jerry puts High Frontier weapons in the grip of the invading ftfhp, but mine is the vision of baby elephants in tennis shoes gliding out of the sky sky under paper airplanes. under paper airplanes.

And I wrote the story that demonstrates that fog is the visible sign of a merging of time tracks.

The bar was selling a lot of Irish coffee that night. I'd bought two myself. It was warm inside, almost too warm, except when someone pushed through the door. Then a puff of chill, damp fog would roll in.

Beyond the window was grey chaos. The fog picked up all the various city lights: yellow light leaking from inside the bar, pa.s.sing automobile headlights, white light from frosted street globes, and the rainbow colors of neon signs. The fog stirred all the lights together into a cold graywhite paste and leaked it hack through the windows.

Bright spots drifted past at a pedestrian's pace. Cars. I felt sorry for the drivers. Rolling through a gray formless limbo, running from street globe to invisible street globe, alert for the abrupt, dangerous red dot of a traffic light: an intersection; you couldn't tell otherwise. . . I had friends in San Francisco; there were other places I could be. But it wasn't my city, and I was d.a.m.ned if I'd drive tonight.

A lost night. I'd finished my drink. One more, and I'd cross the street to my hotel.

"You'd best wait until the fog thins out," said the man next to me.

He was a stranger, medium all over; medium height and weight, regular features, manicured nails, feathery brown hair, no scars. The invisible man. I'd never have looked his way if he hadn't spoken. But he was smiling as if he knew me.

I said, "Sorry?"

"The point is, your hotel might not be there when you've crossed the street. Don't be surprised," he added. "I can read minds. We've learned the knack, where I come from."

There are easy ways to interrupt a conversation with a stranger. A blank stare will do it. But I was bored and alone, and a wacky conversation might be just what I needed.

I said, "Why shouldn't my hotel be exactly where I left it?"

He frowned into his scotch-and-soda, then took a swallow. "Do you know the theory of multiple world lines? It seems that whenever a decision is made, it's made both ways. The world becomes two or more worlds, one for each way the decision can go. Ah, I see you know of it. Well, sometimes the world lines merge again."

''But-''

"That's exactly right. The world must split on the order of a trillion times a second. What's so unbelievable about that? If you want a real laugh, ask a physicist about furcoated particles."

"But you're saying it's real real. Every time I get a haircut-"

"One of you waits until tomorrow," said the brown-haired man. "One of you keeps the sideburns. One gets a manicure, one cuts his own nails. The size of the tip varies too. Each of you is as real as the next, and each belongs to a different world line. It wouldn't matter if the world lines didn't merge every so often."

"Uh huh." I grinned at him. "What about my hotel?"

"I'll show you. Look through that window. See the street lamp?"

"Vaguely."

"You bet, vaguely. San Francisco is a town with an active history. The world lines are constantly merging. What you're looking at is the probability of a street lamp being in a particular place. Looks like a big fuzzy ball, doesn't it? That's the locus of points where a bulb might be -or a gas flame. Greatest probability density is in the center, where it shows brightest."

"I don't get it."

"When the world lines merge, everything blurs. The further away something is, the more blurred it looks. I shouldn't say looks looks, because the blurring is real; it's no illusion. Can you see your hotel from here?"

I looked out the appropriate window, and I couldn't. Two hours ago I'd nearly lost my way just crossing the street. Tonight a man could lose himself in any city street, and wander blindly in circles in hopes of finding a curb. .

"You see? Your hotel's too far away. In the chaos out there, the probability of your hotel being anywhere specific is too small to see. Vanishingly small. You'd never make it."

Something about the way he talked...

"I wondered when you'd notice that." He smiled as if we shared a secret.

"All this time," I said, "I've been thinking that you talk just like everyone else. But you don't. It's not just the trace of accent. Other people don't say probability density probability density or or theorem theorem or or on the order of on the order of."

"No, they don't."

"Then we must both be mathematicians!" I smiled back at him.

"No," he said.

"But then . . ." But 1 backed away from the problem, or from the answer. "My gla.s.s is empty. Could you use a refill?"

"Thanks, I could."

I fixed it with the bartender. "Funny thing," I told the brown-haired man. "I always thought the blurring effect of fog came from water droplets in the air."

"Bosh," he said. "Bosh and tish. The water's there, all right, whenever the fog rolls in. I can't explain it. The condensation must be a side effect from the blurring of the world lines. But that's not interfering with your vision. Water's transparent."

"Of course. How could I have forgotten that?"

"I forgot it myself, a long time ago." The scotch was beginning to reach him, I think. He had an accent, and it was growing stronger. "That's why I'm here. That's why I stopped you. Because you'd remember."

The bartender brought us our drinks. His big shoulders were hunched inward against the damp gray light that seeped in the windows.

I sipped at the burning hot gla.s.s. Irish whiskey and strong black coffee poured warmth through me, to counteract the cold beyond the walls. A customer departed, and the fog swirled around him and swallowed him.

"I walked into the fog one afternoon," said the brown-haired man. "The fog was thick, like tonight. A cubic mile of cotton, as we say. I was just going out for a pouch of snuff. When I reached the tobacconist's he tried to sell me a bundle of brown paper sticks with a Spanish trademark."

"Uh huh. What did you do?"

"Tried to get home, of course. Things changed oddly while I wandered in the fog. When it cleared and left me stranded, even my money was no good. The worst of it was that I couldn't even tell my story. n.o.body could read my mind to see that I was sane. It was find another fog bank or try to make a life for myself."

"With no money?"

"Oh, I sold my ring and found a poker game."

"Oh. Oh Oh!"

"That was a year ago. It's worked out well enough. I thought I might invent something, like the zipper, but that fell through. You're far ahead of us in the physical sciences. But money's no problem. Sometimes there's a fixed horse race. Sometimes I find a poker game, or a crooked c.r.a.p game where they'll let me bet the right way."

"Sounds great." But not very honest, I thought.

"You disapprove?" My companion's voice had gone thin and cold.

"I didn't say that."

"I compensate for what I take," the brown-haired man said angrily. "I know how to untwist a sick man's mind. If a player sits down with emotional problems, I can help him. If he really needs the money, I can see that it comes to him."

"Why don't you become a psychiatrist?"

He shook his head. "It would take years, and then I'd never be able to hold a patient long enough to do myself any good. He'd get well too fast. Besides that, I hate hate certain people; I'd want to harm them instead of helping them. . certain people; I'd want to harm them instead of helping them. .

"Anyway, I don't go out in the fog anymore. I like it here. I stopped you because you're one of those who remember."

"You said that before. What exactly-?"

"After all, people are constantly walking into fogs. Why is it that we don't hear more about people wandering in from alternate world lines? It's because their memories adjust."

"Ah."

"I caught it happening once. A girl from somewhere else. . . I didn't catch the details; they faded too fast. I got her a job as a go-go dancer. I think she was a prize concubine in someone's harem before she ran into the fog.