"We are another ten minutes behind schedule," Baedeker admitted. That came to eighty minutes, total, so far. "Still no real problems, I just underestimated the complications of working out here."

"I'm suited up and ready to help," Eric offered.

"Eric, I would rather you stay on Don Quixote Don Quixote," Sigmund said firmly.

Baedeker switched to a private channel. "Sigmund, I can use the help. The Gw'oth are exhausted. Half the General Products engineers have returned"-some fled; more carried, comatose, on floaters-"back to Haven Haven." And I am hanging on to sanity by my teeth.

"Give me a moment," Sigmund said.

Baedeker could guess at Sigmund's hesitation. Eric on the ground would mean only Kirsten and Jeeves left aboard with Thssthfok.

Sigmund returned to the common channel. "All right, Eric. It sounds like you'll be more useful on the ground."

"Breaking orbit to match velocities with the ground," Kirsten said cheerfully. A few minutes later, she added, "Watch that first step, Eric."

WORKING BY TOUCH Thssthfok visualized the exposed circuitry within the anklet. Some components-resistors, capacitors, integrated circuits, and the like-hinted about themselves by their shapes and sizes. Other components remained unidentified, their nature left to discovery through inference. Interconnection patterns suggested human devices he had scanned before, when he had still had his repair kit and its instruments.

The anklet contained either an inertial position sensor or the ability to locate itself relative to nearby transmitters. It would contain a transmitter to report its own position. It would sense whether the clasp remained sealed.

He catalogued the functions the anklet might perform, then started designing the circuitry and stored program as humans would. His third design incorporated every component he had identified by touch, used consistently with what he had scanned in other human devices. Hence: This This was the test subsystem. It would provide the means to confirm the anklet could identify any internal failure and then radio the self-diagnosis. was the test subsystem. It would provide the means to confirm the anklet could identify any internal failure and then radio the self-diagnosis.

With a little effort, he could expand that output repertoire.

KNOWING IT WAS HIS IMAGINATION, Sigmund felt the cold creep through his insulated boots, up his legs, into his body. This s...o...b..ll was not much above absolute zero. Having nothing to do but watch and wait somehow made the cold worse.

It wasn't only the cold. The stars shone diamond hard, without a hint of a twinkle. Any trace of atmosphere had long ago frozen. And Niflheim had scarcely one-tenth the ma.s.s of New Terra. Niflheim was also physically smaller, of course, raising its surface gravity to a whole one-third of what he was accustomed to. The horizon was much too close, crowding him....

An attack-no, a full-blown, incapacitating seizure-of flatland phobia seethed in Sigmund's brain. The ground, the sky, everything everything began spinning.... began spinning....

Not now, tanj it! He pulled himself together to scan across the busy construction site, wanting to demand another progress report, knowing it was too soon.

Knowing also that everything was going far too smoothly.

ER'O SIDLED ON THREE LIMBS around another of the drive modules. A motor in his exoskeleton had failed in the extreme cold, immobilizing a tubacle. He held the fifth tubacle aloft, clutching a scanner as he re-inspected his work.

"We will be ready in a few minutes for an end-to-end system test," Baedeker said. "Full power to all compon-"

"I have an unexpected reading on sensors," Minerva transmitted.

Er'o looked at the equipment spread across the ice. The modules all looked the same. They would, until one of them tore him to atoms. "Which unit?"

"Not on Niflheim. Half a light-day away, pa.s.sing by."

"What sort of reading?" Sigmund demanded.

"Astronomical, surely," Minerva answered calmly. "A magnetic monopole. Maybe more than one."

Baedeker whistled impatiently. "All right. Track it while we run the end-to-end test."

Sigmund was not ready to drop the subject. "Pa.s.sing by? Send me its course."

"Me, too, please," Er'o said. A gentle arc appeared on one of his displays, and presumably also on Sigmund's helmet. The arc curved toward, but not directly at, Niflheim. "Why does it turn?"

Minerva said, condescendingly, "Presumably it is in an electric field."

Ion currents permeated s.p.a.ce-even here, so far from any star. Yes, there could be an electric field. But a field that strong? While others prattled about solar winds and the interstellar medium, and the electromagnetic fields they generated, Er'o consulted with the other Gw'oth. Compared to a meld their deliberations felt painfully slow.

Er'o interrupted the others' speculations. "It is not anything natural. That is a ramscoop with its engine off, using its magnetic scoop as a brake."

"Finagle," Sigmund swore. "Are you sure, Er'o?"

"Someone else should confirm my calculations, but yes, I am sure."

"Finagle," Sigmund said again. "Minerva, Jeeves, Kirsten, don't use active sensors. We don't want that ramscoop to know we know it's coming. Learn what you can on pa.s.sive. Everyone, our radios are low power, but let's play safe and keep the chatter to a minimum."

"You don't mean to keep working?" Baedeker said. "The Pak are coming!"

"Let's confirm that," Sigmund said.

"Er'o is correct," Jeeves offered. "There is a weak neutrino source near the center of the magnetic anomaly. Observed deceleration fits with the drag from a magnetic ramscoop field. Well behind is a trail of concentrated helium."

A ramscoop with its drive off, its fusion reactor turned down, decelerating stealthily.

Ice shards flew from beneath Baedeker's suddenly frantic hoof. "We must go."

"Wait!" Sigmund said. "Anyone, what's the soonest that ship can get here?"

Jeeves completed the calculation first. "I don't know how good a Pak fusion drive is. a.s.suming similar performance to my drive aboard Long Pa.s.s Long Pa.s.s, about a day. That is if they immediately abandon sneaking up and switch to full acceleration toward us."

"About a day for a flyby attack," Sigmund said. "They're decelerating because they mean to land here." He stared up into the jet-black sky. "They may simply be scavenging for volatiles, going stealthy lest another clan has ships attempting the same."

"Or they are trying to sneak up on us us!" Very un-English grace notes had crept into Baedeker's voice. "We must not let them."

"What we cannot do," Sigmund snapped, "is let Pak capture your technology."

"Then we destroy it and get out of here," Baedeker half said, half sang.

A piercing alarm sounded and was quickly muted. "We have a fire onboard," Kirsten said.

SIGMUND GAZED INTO THE DARKNESS, although Don Quixote Don Quixote was too far off to be seen. "A fire? Where?" was too far off to be seen. "A fire? Where?"

"Deck five," Kirsten said. "I can't tell where the fire started, or how it spread so far before setting off alarms."

The deck with Thssthfok's cell. Except for a bit of bedding, nothing in his cell could burn. Nothing in the cell could start a fire. Sigmund still still couldn't help wondering whether the Pak was responsible. "Is Thssthfok in danger?" couldn't help wondering whether the Pak was responsible. "Is Thssthfok in danger?"

"Enviro sensors say smoke, toxic fumes, and heat. Fire suppression is not working. From audio, he's pounding on the hatch. I've lost video from that deck."

Finagle, fire was a terrible way to die. Sigmund's mind raced. "How's this? Seal the deck, release him from the cargo hold to find someplace safe, and shut emergency hatches behind him. Then open the hold's outer door to kill the fire and vent the fumes."

"I can do that," Jeeves said, "if fire hasn't damaged the circuits or motors I'll need."

What if they were too slow? "Kirsten, suit up. You may have to vent the entire ship."

"Suiting up now, Sigmund."

In the few seconds devoted to the latest crisis, Baedeker had bounded off toward Haven Haven. Sigmund had to refocus on matters here on the ground. "Kirsten, do what you must. Just don't let Thssthfok anywhere near the bridge."

THE LATCH OF THSSTHFOK'S CELL CLICKED open. He rushed out and, for the audio sensors, slammed the hatch behind him. Over the intercom, Jeeves directed Thssthfok away from the fire.

There was no fire, of course, only the illusion injected into shipboard sensors by his modified anklet. Jeeves ordered Thssthfok exactly where he meant to go: a large pantry.

Thssthfok hooked claws inside the jagged tear in the anklet and pulled. The metal bent back with a squeal. He found, just as he had expected, a fragile-looking reservoir of liquid. A current surge would vaporize the liquid, the gas pressure bursting the ampoule and releasing the gas. A radio signal would set it off. Removing the anklet would, too.

He began studying the anklet's control circuits.

THSSTHFOK HAD NOT CHOSEN this pantry casually.

The day of his capture he had been transported instantaneously from an air lock to the cargo hold that became his cell. The humans had forced him to surrender the teleportation disc, but the round indentation where it had lain remained in the deck. His newer cell, the one now filling with "smoke," had an identical empty indentation in its deck. The humans teleported supplies to their storage areas.

He lifted the teleportation disc from the floor of the pantry. The disc had a keypad and a long bank of tiny switches along its edge. During his last escape, he had not had the time to fully examine the disc he had found aboard the little ship. Now he studied the device. The help key sent terse explanations scrolling across a little display. He found a directory of shipboard addresses. Once he found addresses for the bridge or engine room he could jump- In his anklet a magnetic-latch relay clicked impotently, disconnected from the circuit that would release the sedative. He kept working.

The disc's little display blanked. "I've disabled the stepping-disc network," Kirsten called over the intercom. "And now that I've reinitialized the enviro sensors, I see the fire wasn't real. Return to your cell."

Accessing the stepping-disc directory must have been visible to her. He ripped up a deck access panel and slashed claws through the exposed circuits. Sparks flew and gravity vanished from the pantry. He nudged the floating panel out the open door.

Partway to the floor, the bent plate's speed went meteoric. It crashed to the deck, then flattened with a groan.

"The corridor gravity is high, but it won't kill you. Return to your cell or I'll blow you out to s.p.a.ce." There was a catch in Kirsten's throat. "Don't make me do that."

Several sealed rescue bags sat on a nearby shelf. Each had a small air tank. He shut the pantry door and kept studying the disc. Its power light still glowed. If she told the truth the control network was off, but the stepping disc had internal power. Other discs would also have power. Nearby discs might communicate among themselves and he could enter an address manually.

"In one minute," Kirsten warned, "I start venting."

One minute was ample. He began a.n.a.lyzing the part of the directory he had seen.

"ERIC!" SIGMUND RAN AFTER ERIC, bounding toward the nearest stepping disc. "I need you down here."

Eric kept going. "That's my wife, alone with a Pak! I'm going to help her."

"I know! But Baedeker is falling apart. You have to finish the checkout."

Eric was halfway to the stepping disc. "And if it were Penny up there?"

"I'll go up to the ship, tanj it!" Sigmund yelled. "You can finish here if Baedeker goes to pieces. I can't. Vaporizing this planet is the one sure way to keep this technology from the Pak. That protects everyone."

"If anything happens to Kirsten..." Eric's voice shook. His pace began to slow.

Sigmund had better low-gee running technique and caught up. He grabbed Eric by the shoulders and spun him around. "I promise you, it won't."

Within another ten paces, Sigmund stepped aboard Don Quixote Don Quixote.

A STORM RAGED IN THE CORRIDOR, but the pantry-hatch seal was almost airtight. Thssthfok unrolled a rescue bag across the door; suction pulled the tough, clear material into the crack. The whistle of escaping air died.

Wind and the loss of gravity had stirred the pantry. Shelves were half empty now. Drifting containers kept b.u.mping into him and the walls. Revealed on the backs of several shelves: bags of tree-of-life root.

He had seen eighteen stepping-disc addresses and locations. The sample was sufficient to extrapolate addresses to discs elsewhere in the ship-including any on the bridge. He put his disc in send mode, set it gently onto the floor, anch.o.r.ed himself on the disc with a firm grip on a shelf, and waited.

Nothing happened.

The disc, when he checked its display, gave an error code. Receive error. Someone on the bridge had been quick to disable the disc there. Powered down, turned over, put into send-only mode-it didn't matter which. The address he had extrapolated for the engine room resulted in another receive-mode error.

Where should he go before the disc addresses all became useless?

58.