Enigma (30 page)

As Koi slept, as Thackery lay in the darkness and listened to her breathing, as
Munin
sped onward through the AVLO night, far away in the Lynx octant the Pathfinder
Dove
was dying.

The trouble began in a field coil, one of forty arrayed in a ring around the
Dove
’s drive halo and linked by dozens of thick cables to the fore and aft field radiators and to the deck grids which provided the ship’s gravity. The coils were where the flux built up, each an instant later than one neighbor and an instant earlier than the next. That rigid sequential pattern smoothly induced the multiplier effect—forty coils behaving as though they were fully energized, even though only a single coil was at any given instant. It was from that illusory energy that the illusory mass of the drive’s phantom gravity well proceeded.

Each coil was a complex structure of insulated wire as fine as hair and fast-response capacitors as massive as logs, linked by a microprocessor controlled bank-switching system which assured that, picosecond to picosecond, the accumulated charge was in balance. Unless electrons could be considered exceptions, there were no moving parts in the entire 200-kg mass of each coil.

But that did not mean that there was no wear. The AVLO-D coils, unlike those powering later survey ships, were not chilled by exposure to space to superconducting temperatures, and so the fine niobium-zirconium filaments were subject to Joule heating each time the drive was used. Of course, the alloy had been chosen with that in mind, and no detectable damage resulted from the subatomic stress.

But that did not mean that there was no damage. With each flux cycle, random microscopic hot spots were created at the sites of tiny metallurgical imperfections. Over time, the imperfections grew to flaws, and the flaws to actual breaks. Even that had been foreseen, for the bank-switching system simply readjusted the coil’s output to a slightly lower level, the central controller brought the other coils down accordingly, and the drive continued to operate, albeit at a fractionally lower efficiency.

What the engineers who built the drive did not anticipate (and could not have been expected to) was how long the Pathfinder
Dove
would remain operational and how often its drives would be called on to hasten it to one or another new destination. In carrying out the fault-test modeling to twenty-five craze cycles, they were confident that they were providing at least a twenty-cycle margin of safety.

But that margin had been reached and substantially surpassed long ago. Two major overhauls, five tear-down inspections, and three hundred eighty-one years after it was first placed in service, thirty-eight of the forty original coils were still in place. When Commander Dylanna Lapedes, the first Journan to achieve command rank, pronounced the survey of 61 Canum Venaticorum complete, it was those coils which responded to the gravigator’s call and started
Dove
smoothly on its way.

And less than an hour later, as
Dove
reached a velocity of some 100,000 kilometres per second, it was coil Twenty-Eight, built in a Copenhagen assembly plant and installed on-orbit by the grandson of a New York street merchant, that failed.

It failed suddenly and spectacularly, with blue-white gigawatt arcs dancing inside the cylindrical housing, leaping from one subassembly to another. Within seconds, the superheated gases generated by burning insulation and vaporized wire filament exploded outward, and the starboard half of
Dove
’s drive halo became an inferno. The skin of the ship bulged, then split open in a great tattered rent. An instant later, the conflagration was out, deprived both of spark and oxidizer by its own violence.

The pressure vessel which comprised the climbway and the adjacent living spaces had not been broached, and though everyone was shaken, no one aboard
Dove
had been killed. There was still light, and air, and food, and those systems not dependent on the drive still functioned. But
Dove
herself was mortally wounded, and the velocity at which she was moving condemned her crew to death.

For without the protective bow wave of the AVLO drive, the smallest bit of space flotsam would strike
Dove
like a bomb, turning the energy of
Dove
’s own motion against it. Neither the gig nor the lifepods, their hulls and propulsion systems equal only to the modest demands of in-system flight, offered any hope of escape. And the cometary cloud belonging to 61 Canum Venaticorum lay but a few minutes ahead. Under the AVLO drive, the cloud was a triviality, a tissue of microscopic dust and infinitesimal ice crystals. With the drive destroyed, the cloud was an impassable mine field.

There was enough time only for a brief final dispatch, transmitted by the tortoise of radio rather than by the rabbit of the drive-dependent Kleine, and for a few hapless tears and desperate prayers.

For a long minute it seemed that luck had favored
Dove
. Then a kernel of icy dust no larger than a pinhead intersected
Dove
’s trajectory. The energy of the collision sheared off half the forward radiator and shattered the bridge deck.
Dove
began to slowly tumble end for end, its atmosphere and crew spilling out through its wounds. Then, disemboweled and beheaded, the aging Pathfinder finally died.

Dove
’s last transmission was first received by the survey ship
Edmund Hillary
, some twelve light-years away in the same octant. The transmission was not a plea for help, for Commander Lapedes had known, and
Hillary
was forced to acknowledge, that
Dove
and its passengers were beyond helping. All
Hillary
could do was speed the news of its destruction to A-Cyg, Unity and the rest of the fleet.

By that time
Munin
had finished its work at 29 Sagittae and was more than halfway to its next destination. Deafened by the craze,
Munin
did not catch Hillary’s dispatch. Consequently, it was not until they regained their senses inbound to the next system that they learned of
Dove
’s fate.

The news came in a Priority command dispatch, which Cormican shared over the shipnet a half-hour after it was brought to him:

You are hereby directed to discontinue your current operations and effect the return of
Munin
to Advance Base Cygnus. Your immediate acknowledgment of and compliance with this directive is required.

The Technology Office evaluation of the circumstances surrounding the loss of USS 4 Dove concludes that said incident was related to catastrophic failure of AVLO-D drive S.N. 101-044. This failure has been judged to be non-anomalous and all similarly equipped vessels are considered AT RISK. All due discretion is recommended for your return, including restricting drive output to 30 degrees or less and continuous monitoring during the acceleration and deceleration phases.

Appended find copies of the relevant accident report, accident inquiry, and technical evaluation.

“Personally, I don’t see any reason we couldn’t complete a survey of this system,” Cormican concluded, “but the orders don’t seem to leave any room for that. I’ve asked the gravigation and engineering staff to conduct a full diagnostic test of the drive. They have advised me that will take most of the rest of the day, so I am tentatively scheduling us to begin the acceleration phase of our trip back to A-Cyg for ten tomorrow morning.

“I’m as sorry about this as you are, but it does seem the prudent thing to do. I haven’t been told how your contracts will be handled, but be assured I intend to make a case with the Flight Office that our return be considered end-of-tour and that everyone receive a full payout. Thank you for your attention.”

Thackery was alone in the survey lab when the announcement began, and afterwards headed upship to find someone to talk to about it. He found that a half-dozen of the crew had already gravitated to the edrec deck, and a loud and multifaceted discussion was already underway. Thackery joined the gathering and listened.

“But, good Christmas, a thirty-degree slope—,” one of the awks was saying, “It’ll take us ten days just to craze.”

“Ron’s already worked it out—fifty-seven days back to A-Cyg.”

“See? That’s got to be the slowest leg anybody’s run since
Pride of Earth
went out.” Connolly said, “It’ll make it tough on Amy—running that long in the craze with an iffy drive to think about.”

“I heard that,” Koi called as she stepped off the climbway to join them. “Don’t listen to him, folks. I happen to know he’s been holding a tranq pump in reserve for himself.”

There was laughter, and she came and stood by Thackery, close but not touching, friendly but reserved, just as she had been since moving out at 29 Sagittae. “What do you think?” she asked quietly.

“I really don’t know yet.” He expected her response to be
You should be happy—here’s your chance to go home early
, or
how did you arrange it? I don’t want to go home
, he was ready to answer.
Not now. Not alone
.

But all she said was, “I feel bad for
Dove
’s crew. They had a little more time to think about what was coming than I’d like to have.” And then she moved off to sprawl in an empty chair opposite from where Thackery stood.

Thackery did not, in fact, know how he felt, which was why he was listening, and not talking. He was somewhat surprised that most of the others seemed to be taking it as an interruption, a bureaucratic annoyance, rather than as a respite or an early furlough. Gwen Shinault, the senior tech. was actually angry.

“This is totally unnecessary,” she proclaimed loudly. “If they would just let us program the controller to shut the drive down instead of trying to juggle an unbalanced flux, there’d be no need to recall us. If
Dove
’s controller had been wired that way, I’d wager she’d still be in one piece.”

“And stranded way the hell out in Ursa Major.”

“I’ll make you a bet you won’t take that
Dove
’s crew’d have been glad to have that choice if someone’d offered it.” The loudest part of the conversation shifted to another part of the room. “What do you think they’ll do with
Munin?
”

“You mean if we get it back?”

“Oh, hell, we’ll get back,” said one of the awks cheerily. “I’m with Gwen. I wouldn’t have second thoughts about ignoring the directive and just continuing on.”

“You’re not smart enough to have second thoughts” was the response, to general laughter. “They’ll scrap her, of course. What else can they do?”

“Why not replace the drive?”

“If you ever wondered why you’re still an awk, it’s because of bone-headed statements like that one. Why do you think the Pathfinders still
have
AVLO-D drives? They’re building
Cygnus
with an AVLO-M, for crissakes. If replacement was a workable proposition, it’d have been done a long time ago. Bennie’s right. The only thing to do is scrap her. She’s expendable.”

No, no, ho—not if I have anything to say about it
, Thackery thought with sudden elation. He tried to catch Koi’s eyes, but she was looking in another direction.

Just as well
, he thought, catching himself.
It’d be wrong to say anything. She’s made clear she’s not interested in being won back—not that I ever “won” her in the first place
.

With a nod of acknowledgment to those who noticed him leaving, Thackery slipped away and headed downship, his thoughts still racing.

She’d only think you were doing it because of her, anyway, and there’d be nothing gained from that. That’s not the reason. That never was the reason. I have to do it for myself
.

He reached D deck and hastened along the short corridor to his cabin, where he took up his slate and curled up in the only chair.

No. That’s the wrong reason too
, he thought as he accessed the ship’s library.
I have to do it because I’m the only one who can. I’m the one who knows. I’m the one who sees. If I don’t do it, no one will—which just maybe is what she was trying to say
.

There was no desk in the putative office of the Cygnus liaison of the Committee on ReCreation of First Colonization Planning, making Thackery wonder briefly if he had been led merely from one waiting room to another. Then a short, slender man swathed in a silky amber wrap rose from a chair facing the greatport and turned toward Thackery.

“Mr. Thackery. I’m Eloi Zamyatin. I’m very pleased to have the chance to meet you.” The liaison extended his hand palm-up in the Daehne gesture of greeting that was current at A-Cyg, then settled back in his chair.