We linger round the outside of the top hatch while reluctant enlisted men go popping through like corks too small for the neck of a bottle. Some go feet first, some head first, diving behind their duffel. The hatch is a mere half meter in diameter. The men have to scrunch their shoulders to fit. Westhause is explaining the airlock system. "The only reverse flow consists of wastes," he concludes.

"And you give that any significance you want," the Commander mutters. "Shit for shit, I say. Down the hatch, men."

"Whatever happened to your youthful enthusiasm?"

The Commander refuses the bait. He has said too much already. A wrong word falling on an unfriendly ear can flatten a career trajectory. Climber Reel One operates on a primitive level. is a long, long way from Luna Command. The Admiral enjoys near dictatorial powers. The proconsular setup derives logically from the communications lag between Canaan and the centers of power. It's hard to like, but even harder to refute.

Fleet personnel can wish they had a more palatable overlord.

They call the central cylinder the Can. The Can is incredibly cramped, especially in parasite mode, while attached to the mother. Then, artificial gravity runs parallel to the cylinder's axis.

In operational mode, when the Climber provides its own gravity, the Can's walls become floors.

Even then there'll be very little room if everyone is awake at once.

I take one long look around and ask, "How do you keep from trampling each other?"

"Some of the men are in their hammocks all the time. Unless we're in business. Then everybody is on station."

The Can is fifteen meters in diameter and forty meters tall. Doubled pressure partitions separate it into four unequal compartments. Operations Division, the brains of the ship, occupies the topmost level. Immediately below is Weapons. The two divisions share their computation and defection capacity. The third level is Ship's Services. It's the smallest. It contains galley, toilet, primitive laundry and medical facilities, recyling sections, and most importantly, the central controls by which internal temperature is sustained. Below Ship's Services is Engineering.

Engineering's main task is to make the ship go from point A to point B. Their equipment, systems, and responsibilities often overlap with Ship's Services'.

A central structural member, called the keel, runs the length of the cylinder. When the ship is in operational mode the crew will take turns sleeping in hammocks attached to it. That's something to think about. I've never tried extremely low gravity sleep. I hear that it's hard to get a good rest, and dreams become a little crazy.

In parasite mode sleeping arrangements are catch-as-catch-can, with the quickest men hanging hammocks from available cross-members, then negotiating sharing deals with slower shipmates. Some of the places hammocks get slung seem almost too small for mice.

The luxury quarters of any ship, the Ship's Commander's stateroom, here consists of a screened-off section of beam near the entry hatch. He'll share his hammock with the First Watch Officer and Chief Quartermaster. Every hammock will be shared. It takes no imagination to see the potential for havoc in that. It takes some complex shuffling to put three men in one hammock and allow each a reasonable day's ration of sleep. I suspect Command would prefer android crews who need no sleep at all.

There's little open space inside the cylinder. The curved inner hull supports most of the consoles and working stations, with little separation between them. Two meters off the hull the inner circle begins. There're a few duty stations on that level, but most of the space is occupied by the ship's nervous and circulatory systems, and those parts of her organs which don't need to be instantly accessible. With the exception of a few holes providing access to the two-meter tunnel around the keel, the central eleven meters of the Can are an impenetrable maze of piping, conduit, wiring, junctions, humming boxes of a thousand shapes and sizes, structural beams, and ductwork.

I have to ask. "How the hell can human beings work in this jungle gym?"

Westhause smiles. "Looks better on holo, doesn't it?" Clambering around like a baboon in pants, he leads me to an abbreviated astrogator's console. Flanking it are a pair of inputI output consoles for the ship's main computation battery. Nudging up in front, like a calf to its mother, is the tiniest spatial display tank I've ever seen. I've see cheap children's battle games with bigger tanks. With a perfectly straight face, Wet-hause reminds me, "It won't be as nasty after we go on ship's gravity."

"Any way is up when you can't get any farther down."

An argument breaks out in the keel passageway. Wanting to appear conscientious, I move toward the nearest access way.

"Never mind. They'll settle it. That's Rose and Throdahl. They're always fussing about something."

"If you say so. Where're the lockers, Waldo?"

"Lockers?" He grins. It's a mean grin. A sadist's grin. Your basic got-you-by-the-balls-and-never- going-to-let-go grin. "You are fresh meat, aren't you? What lockers?"

"Gear lockers." Why am I going on? I have one foot poised over an abyss now. "For personal gear."

I didn't expect the comforts of Officer's Country aboard a Main Battle, but I did figure on lockers. I can't leave my cameras lying around. Too much chance they'll walk away.

"You use your hammock. Your bunkmates sleep with it."

Comes the dawn. "No wonder nobody brings anything with them."

"Just one of the luxuries they've taken away. That's why the limited modifieds, like the Eight Ball, are so popular. Rumor is, they've still got a shower on old Number Eight."

"And I thought we had it bad in the bombards."

"That's right. The Old Man said you were in destroyers back when. Did my original active duty there. Luxury liners compared to this. Hello, Commander."

"There's got to be a better way."

The Commander shrugs as if to say that's a matter of complete indifference to him. He smiles a thin, grim smile that seems carefully studied, the secretive smile of a Commander on top of it all and mildly amused by the antics of the children in his charge. "Nature demands .her price. Board all squared away, Mr. Westhause?"

"I'm just starting my check sequence, Commander."

I take the hint. I'm in the way here. Everyone else is busy, too. The compartment is in a state of chaos. The sleeping arrangements seem fairly well settled. The men are slithering over and around one another to examine their duty stations. Despite the care the ship has received in wetdock, they want to double-check everything. It isn't that they mistrust the yard-birds' competence. They just want to know. Their lives depend on their equipment.

As I wander, I ponder the mystery of the Old Man. If anything, he's more taciturn, more remote, now that we've boarded the ship. He changed masks when he passed through the entry hatch. He turned on some sort of Commander's personality engineered to fit a profile of crew expectations.

Strong and silent, competent and confident. Tolerant of infractions in the personal sphere, strict regarding anything that might affect the welfare of the ship. I've seen the act before, on other ships. Never have I seen it assumed with such abruptness, such cold calculation. I hope he mellows out. I hope he doesn't exclude me from his thoughts entirely. He's half the story here.

Westhause changed, too, when the new Commander passed through his orbit. In moments he was oblivious to anything but his astrogational toys.

There must be a magic in the Climber. The Old Man and Westhause went away. First Watch Officer arrived. Lieutenant Yanevich is treating me like an old friend. Who else shifted personalities at the hatchway? Bradley? I don't know. I haven't seen him since we came aboard. I don't know any of the others.

I get out of their way in Ops by going exploring below. I don't run into anyone with the time or inclination to talk till I reach the bottom of the can. There I meet Ambrose Diekereide, our Engineer-in-Training.

I spend an hour talking the man's speciality. He loses me after the first five minutes.

Surviving Academy requires an acquaintance with physics.

1 got through the courses on stubborness and an elaborate system for memorization. I have a mind which surrounds itself with armor plate when it's faced with a physics more subtle than that imagined by Isaac Newton. I guess I really do see the fuzzy outlines of what Einstein said.

Reinhardt and hy-permechanics I take on faith. Despite Diekereide's heroic effort and all my pre- reading, null and Climbing will remain pure witchcraft till the day I die.

Diekereide says it's possible to look at our universe from a continuum of viewpoints. Classical.

Newtonian. Einsteinian. Reinr-rdter. All points on the spectrum, like the central wavelength line of each color cast by a prism.

The defining parameter of the Einsteinian view is the constant c, c being the velocity of light in a vacuum.

Then along comes Reinhardt, who turns it all over by saying

2 + 2 = 4 sometimes, and c is a constant only under certain special conditions, although those conditions obtain almost everwhere almost all the time. He conjured functions to demonstrate that

gravity is the real universal integer.

Somewhere between those two views is where I start finding moss on both sides of the trees.

Diekereide tells me to imagine the universe as an orange. Okay. That's easy enough, even though my eyes tell me the universe is infinite. Hyperspace, where the Newtonian and Einsteinian rules break down, is the rind of the orange. Fine and dandy. Now friend Diekereide grips the orange like a baseball and throws the hard slider. He tells me the rind exists everywhere coequal with the universe it contains. An orange that is part rind all the way to the pips. Relates back to the curvature of space, where, if you head off on a straight line and stick with it long enough, you get back to where you started. Only, using Reinhardt's math, you can take shortcuts because in hyperspace every point touches every other point. In perfect hyperspace, which seems to be as mythical as perfect vacuum, you can travel the light years between point A and point B in no elapsed time.

Go explain me a cloud. Go out and explain me one of those great wads of wool called cumulus or cumulonimbus. Look it up in a book, how it works. Take that on faith. When I look at a cloud, I always wonder why the son of a bitch doesn't fall like a rock. Like a big hunk of iceberg, down, scrunch!

There is no pure hyper because it's polluted by leakover of time, gravity, and subnuclear matter, though the matter is not really matter in that state. Quarks and such, which aren't allowed to exist there, sit around shifting charge in zero elapsed time-----