Why four rails were needed per track was one more mystery in the Quadrail’s stack of unanswered questions. Two rails this size were required for physical stability, and a third could be explained if power was being run to the trains from an external source. But no one could figure out why the system needed a fourth.

  Most people probably never even wondered about it. In fact, at this point in their journey, most people didn’t even know the tracks were there. The first thing everyone noticed when they first entered the Tube was the Coreline.

  The official rundown on the Quadrail described the Coreline as an optically coruscating pipe inside the Quadrail Tube of unknown composition and purpose, which was rather like describing a bird of paradise as a flying thing with colors. Ten meters in diameter, glowing and sparkling and flashing with every color in the spectrum—including deep infrared and ultraviolet—the Coreline was like a light show on caffeine overdose. At apparently random intervals the pattern changes increased in speed and intensity, and most people swore they could see the thing writhing like an overtensioned wire getting ready to snap. The loose wire meshwork that encased the Coreline another dozen meters out added to the illusion, looking like a protective safety screen put there to protect passengers from shrapnel if and when the thing finally blew.

  Fortunately, sensor measurements had long since proved that the writhing was just another optical illusion. Those same measurements had also confirmed that the aptly named Coreline did indeed run along the exact geometric center of the Tube.

  And that was all the sensors revealed. Most of the experts agreed that the Coreline was the key to how the Quadrail system operated—all except those who insisted it was the fourth rail, of course—but that was as far as anyone had ever gotten. No scanning equipment compact enough to fit through the Tube’s hatches had enough power to penetrate the Coreline’s outer skin to see what kind of equipment was tucked away inside, and the more powerful warship-class sensors couldn’t penetrate the outer wall of the Tube itself. Information stalemate, in other words, which was exactly how the Spiders liked it.

  “Welcome, traveler,” a flat voice said in my ear.

  Speak of the devils. Adjusting my expression to neutral, I turned around.

  A Spider was standing behind me, a gray half-meter-diameter sphere hanging beneath an arching crown of seven segmented legs, the whole thing softly reflecting the Core-line’s ongoing light show. The whole thing was about twice my height, with the sphere hanging half a meter above my eye level, which marked this particular Spider as a maintenance drudge. That alone was noteworthy; usually it was the smaller conductors who did whatever communicating the Spiders deemed necessary. “Welcome yourself,” I replied wittily. “What can I do for you?”

  “Where is your luggage?” it asked.

  I looked back at the mass of bags being ferried up from the shuttle, some of them starting to roll away as their owners keyed their leashes. “Over there somewhere,” I said, pointing. “Why?”

  “Please bring it here,” the Spider said. “It must be inspected.”

  I felt my stomach tightening. In all my previous trips aboard the Quadrail the only times I’d seen anyone’s luggage pulled for inspection was when the Spiders’ unobtrusive sensor array had already decided there was something inside that violated their contraband rules. “Certainly,” I said, trying to sound calm as I tapped the leash button, hoping fervently that the bags wouldn’t embarrass me by dying halfway.

  For a wonder they didn’t, successfully maneuvering their way around the rest of the luggage to where the Spider and I waited. “Shall I open them?” I asked.

  “No.” The Spider stepped over them and shifted to a five-legged stance, deftly inserting the ends of its other two legs into the handles and lifting the bags into the air like a weight lifter doing bending bicep curls. “They will be returned,” it added, and strode off toward one of the buildings beside the track where my Quadrail was scheduled to arrive.

  I watched it go, wondering like everyone else in the galaxy what the devil was inside those dangling globes. But the Spiders’ metallic skin was just as effective at blocking sensor scans as the Coreline was. They could be robots, androids, trained ducks, or something so weird that no one had even thought of it yet. It disappeared-into the building, and with a sudden premonition, I spun around.

  The Girl was standing over by the pile of luggage, her carrybag at her feet, watching me. For a second we held each other’s gaze across the distance. Then, as if she’d just realized that I was looking back at her, she lowered her eyes.

  Scowling, I turned and headed for me platform. If the Quadrail was on time and I’d never heard of one being late it would pull into the station exactly eight minutes from now. Thirty minutes after that, it would pull out again, with me on board.

  The Spiders had until then to return my luggage, or there was going to be hell to pay.

  Seven minutes later, far down the Tube, the telltale red glow of our Quadrail appeared.

  The rest of the passengers had gathered on the platform, and once again I could hear the amazed and slightly nervous twitterings of the first-timers. The train approached rapidly, the red glow resolving into a pair of brilliant laserlike beams flashing between the engine’s oversized front bumper and the Coreline overhead. In the spots where the beams touched it, the Coreline’s own light show became even more agitated, and I amused myself by watching out of the corner of my eye as several of the uninitiated eased a few steps backward. The lasers winked out, and the dark mass resolved into a shiny silver engine pulling a line of equally shiny silver cars, the whole thing decelerating rapidly as it neared the platform. The engine and first few cars rolled past us, and with a squeal of brakes the Quadrail came to a halt.

  There were sixteen cars in this particular train, each with a single door near the front. The doors irised open simultaneously and each disgorged a conductor Spider, a more or less Human-sized version of the drudge who’d made off earlier with my luggage. The conductors moved to the sides of the doors and stood there like Buckingham Palace sentries as lines of Humans and aliens maneuvered their carrybags out onto the platform and headed for either the waiting rooms or the glowing hatchways marking the spots where shuttles were waiting. At the rear, drudges were busily removing larger pieces of luggage from the baggage car for transfer to the shuttles, while on the far side of the train I knew other drudges would be doing likewise with the various undercar storage compartments.

  I looked toward the front of the train, where a pair of drudges had reached the engine. One of them set its feet into a line of embedded rings and climbed partially up the side to a slightly lumpy box set into the engine’s roof just behind a compact dish antenna. Two of the spindly legs reached up and popped the box lid open, delicately removing a flattened message cylinder and handing it down to the other drudge waiting below. The second Spider accepted the cylinder and passed up one of its own, which the first then replaced in the box. Deceptively compact, those cylinders were packed with the most current news from around the galaxy, along with private electronic messages and encrypted data of all sorts.

  Passengers, cargo, and mail, the ultimate hat trick of any civilization. All of it running via the Quadrail.

  All of it under the control of the Spiders.

  A few minutes later the outward flow of passengers ended, and the line of conductors took a multilegged step forward. “All aboard Trans-Galactic Quadrail 339216, to New Tigris, Yandro, the Jurian Collective, the Cimmal Republic, and intermediate transfer nodes,” they announced in unison, verbalizing the information that was also being given by a multilanguage holodisplay suspended over the train. “Departure in twenty-three minutes.”

  The crowd surged forward as the Spiders repeated the announcement in Juric and Mahee, rather a waste of time since there weren’t any Juriani or Cimmaheem waiting for this particular Quadrail. But procedure was procedure, as I’d learned during my years of government service, and not to be trifled with merel
y because it didn’t happen to make sense. Circling around the back of the crowd, I headed for Car Fifteen, the last one before the baggage car.

  My ticket had come edged in copper, which had already indicated it was one of the lower-class seats. But it wasn’t until I climbed through the door and stepped past a stack of safety-webbed cargo crates into the aisle that I realized just how far down the food chain I actually was. Car Fifteen was a hybrid: basically a baggage carrier, stacked three-deep on both sides with secured cargo crates, with a single column of thirty seats shoehorned like an afterthought between the aisle and the wall of boxes to the right.

  A half dozen nonhumans were already seated: Cimmaheem, Juriani, and a lone Bellido, none of them paying any attention to me as I worked my way down the aisle. The Juriani, looking like upright iguanas with hawk beaks and three-toed clawed feet, had the unpolished scales of commoners, while the pear-shaped Cimmaheem wore their shaggy yarnlike hair loose instead of in the elaborate braids of the higher social classes.

  I paid particular attention to the Bellido as I approached him, checking for the prominently displayed shoulder holsters and handguns that typically conveyed status in their culture. Actual weapons weren’t allowed inside the Tube, but the Bellidos had adapted to the Spiders’ rules by replacing their real guns with soft plastic imitations when they traveled.

  To me, the aliens always came off looking rather ridiculous, like tiger-striped, chipmunk-faced children playing soldier with toy guns. Given that outside the Quadrail their guns were real, I’d made it a point to keep such opinions to myself.

  But this particular Bellido’s shoulders were unadorned, which was again pretty much as I’d expected. Interstellar steerage, the whole lot of us. Whoever my unknown benefactor was, he was apparently pretty tight with a dollar.

  Still, this car would get me to Yandro as fast as the first-class seats up front. And for once, at least, I wouldn’t have to worry about a seatmate of excessive with or questionable personal hygiene.

  And then, as I passed the Bellido, he gave me a look.

  It wasn’t much of a look, as looks go: a casual flick upward of his eyes, and an equally casual flick back down again. But there was something about it, or about him, that sent a brief tingle across the back of my neck.

  But it was nothing I could put my finger on, and he made no comment or move, and I continued on back to my seat. Thirteen minutes later I heard a series of faint thuds as the brakes were released. A few seconds after that, with a small jolt, the train began moving forward. A rhythmic clicking began from beneath me as the wheels hit the expansion gaps in the railing, a rhythm whose tempo steadily increased as the train picked up speed. My inner ear caught the slight upward slope as we left the station area and angled up into the narrower part of the main Tube. A moment later we leveled out again, and were on our way to Yandro. A total of eight hundred twenty light-years, a nice little overnight train ride away.

  Which was, of course, the part that really drove the experts crazy. Nowhere along our journey would the Quadrail ever top a hundred kilometers per hour relative to the Tube itself. That much had been proved with accelerometers and laser Doppler measurements off the Tube wall.

  Yet when we pulled into Yandro Station some fourteen hours from now, we would find that our speed relative to the rest of the galaxy had actually been almost exactly one light-year per minute.

  No one knew how it worked, not even the six races who claimed to have been with the Quadrail since its inception seven hundred years ago. They couldn’t even agree on whether speeds in this strange hyperspace were accelerated or whether it was the distances themselves that were somehow shortened.

  In the past, I’d always thought the argument mostly a waste of effort. The system worked, the Spiders kept it running on time, and up to now that was all that had mattered.

  But that had been before everything that had happened at the New Pallas Towers a week ago.

  And, of course, before the Spiders had lost my carrybags. I could only hope they’d ended up somewhere else aboard the train and that I would find them waiting when I got off at Yandro.

  Tilting my chair back, I pulled out my reader and one of the book chips from my pocket. A little reading while everyone got settled, and then I would take a trip through the rest of the third-class coaches to the second/third-class dining car. There was a chance my unknown benefactor was aboard the train with me, planning to make contact once we got off, and it would be a good idea to run as many of the passengers as I could through my mental mug file.

  But even as I started in on my book, I found my vision wavering. It had been a long trip from Earth, and I was suddenly feeling very tired. A quick nap, I decided, and I’d be in better shape to go wandering off memorizing faces. Tucking my reader away, I set my watch alarm for an hour. With one final look at the back of the Bellido’s head, I snuggled back as best I could into my seat and closed my eyes.

  I awoke with a start, my head aching, my body heavy with the weight of too much sleep, my skin tingling with the sense that something was wrong.

  I kept my eyes shut, my ears straining for clues, my nose sifting the air for odd scents, my face and hands alert for the telltale brush of a breeze that would indicate someone or something was moving near me.

  Nothing. So what was it that had set off my mental alarms?

  And then, suddenly, I had it. The steady rhythm of the clacking rails beneath me was changing, gradually slowing down. The Quadrail was coming into station.

  I opened my eyes to slits. My chin was resting against my breastbone, my arms folded across my chest with my watch visible on my wrist. Two hours had passed since our departure from Terra Station: an hour longer man I should have slept, three hours less than it took to get to New Tigris.

  So why—and where—were we stopping?

  Carefully, I lifted my head and opened my eyes all the way. When I’d gone to sleep there had been six other passengers besides me in the car. All six had disappeared.

  Or perhaps not. No one was visible, but in front of the stack of crates on my right, in the narrow space leading to the exit, I caught a slight movement of shadow. Someone, apparently, was standing by the car’s door.

  The Bellido?

  I slid sideways out of my seat, my heartbeat doing a nice syncopation with me click-clack of the wheels, and started forward. Theoretically, the Spiders didn’t permit weapons aboard passenger Quadrails. But theoretically, there weren’t any stops between Earth and New Tigris, either.

  I’d covered about half the distance to the door when, with the usual muffled squeal of brakes, we rolled to a halt. The shadow shifted again, and I crouched down behind the nearest seat as the figure stepped into view.

  It wasn’t the Bellido. It was The Girl.

  “Hello, Mr. Compton,” she said. “Would you come with me, please?”

  “Come with you where?” I asked carefully.

  “Outside,” she replied, gesturing to the door beside her. “The Spiders would like to speak with you.”

  THREE

  The door opened, and because I doubted I really had a choice, I followed her out onto the platform.

  At first glance it seemed to be your standard, plain-vanilla Quadrail station. But the second glance showed that there was not, in fact, anything standard about it.

  For one thing, there were only four sets of tracks spaced around the inside of the cylinder instead of the usual thirty. The station itself was far shorter than usual, too, probably only a single kilometer long. Finally, instead of the standard mix of maintenance and passenger-support buildings, the spaces between the tracks were filled with purely functional structures, ranging in size from small office-type buildings to monstrosities the size of airplane hangars, with whole mazes of extra track leading between them and the main lines.

  “This way,” The Girl said, setting off toward one of the smaller buildings.

  I watched her go, my feet momentarily refusing to move. I could think of only one reaso
n the Spiders would possibly want to talk to me, and it wasn’t a particularly pleasant thought.

  And for them to have been willing to stop a whole train to do so made it that much worse. I glanced back over my shoulder, wondering what they were going to tell the rest of the passengers.

  They weren’t going to tell the rest of the passengers anything for the simple fact that there weren’t any other passengers. The rest of the Quadrail had vanished. My car, conveniently emptied of all its occupants except me, plus the baggage car behind it, stood together on the track in front of another engine that had apparently pushed us here.

  “Mr. Compton?”

  I turned back. The Girl had reached the building and was standing expectantly beside the door. “Right,” I said, forcing my feet to move. She waited until I caught up with her, and together we went inside.

  Beyond the door was a small room as drably functional as the building’s exterior, its furnishings consisting entirely of three chairs set in a triangle arrangement facing each other. One of the seats was already occupied by an amazingly fat middle-aged man dressed in shades of blue and sporting a contrasting skullcap of gray hair. Standing behind him was a Spider midway in size between a conductor and a drudge. A stationmaster, possibly, though this one seemed slightly bigger and didn’t carry the usual identifying pattern of white dots across its sphere.

  “Good day, Mr. Compton,” the man greeted me gravely. His voice carried an oddly bubbling quality, as if he were talking half underwater. “My name is Hermod. Please, sit down.”

  “Thank you,” I said, stepping forward and settling into one of the two remaining chairs as The Girl took the third. “Do I get to know where I am?”

  “You’re in a maintenance and storage facility off the main Tube,” he said. “Its actual location is not important.”