Instead, the ship approached on a vector that was tilted at thirty degrees to the ring plane, decelerating the whole way on an inward spiral, reminiscent of the one that had taken them out of Earth orbit.

It was a week's work for the VASIMRs to slow the ship enough to bring it into a circular orbit that threaded the Maxwell Gap; along that spiral trajectory the ship had to cross the ring plane many times. Each ring encounter lasted only a few milliseconds, but they were potentially lethal ones.

Fortunately, Saturn's rings weren't uniform. They were divided into thousands of ringlets and lesser gaps, like grooves on a giant celestial record. The inbound trajectory wasn't a simple smooth spiral. The deceleration was carefully modulated and timed so that each ring crossing would pass through one of those myriad smaller gaps that subdivided the ring system.

Ship's navigation had carried the burden of responsibility for this segment of the flight. This was not the usual preset deep space trajectory, determined well in advance of the flight. From far off, Saturn's rings appeared stable and fixed, but those ringlets performed a constant and chaotic dance with gravity. Gaps would shift kilometers inward or outward. Sometimes they disappeared entirely. Changes could happen in weeks, sometimes days; it was impossible to plan out a precise trajectory far in advance of the Nixon's arrival at Saturn.

So the nav crew actually had to "fly" the ship in, working with a constant stream of communication between the astronomers, Navigation, and Engineering. Navigation would say where they hoped to take the ship, the astronomers would tell them what gaps were close to their desired path, Navigation would calculate a course correction, and Engineering would execute it or tell them it wasn't feasible and they'd better look for a different gap.

It was nerve-racking. Haggard didn't begin to describe the flight crew's appearance by week's end.

- The majority of the ship's complement, who weren't involved in the life-and-death decisions, had an entirely different experience. They were entranced. Saturn, ten times the size of the earth, was a beautiful object to behold. When the Nixon made its first pass by Saturn, outside the F Ring, the flattened disk of Saturn, all by itself, spanned a fifty-degree field of view and the rings, the most gorgeous planetary system known to humanity, filled the sky.

People couldn't get enough of the spectacle. The Commons was always packed to capacity. Anyone whose duties didn't require them to be elsewhere crowded to see the amazing sight that swept past the window. They marveled at the huge pearly-white arcs of the rings and the perpetually fascinating colors of Saturn's cloud bands striped with tawny hues of oranges, ochers, tans, salmons, more different and delicate colors than most of the crew had names for.

The ring crossings were even more popular, if that were possible. Approaching from the sunlit side, the rings grew ever bigger in the window until they occupied the entire view. Unbelievably detailed and striated, rings became ringlets, ringlets parsed into sub-ringlets, ever-finer textures that grew and grew and then suddenly they were through the ring and looking at empty space. Half a rotation of the living modules, and the rings came back into view, sometimes glowing with ghostly pale backlighting from the sun. Where Saturn's shadows fell across the rings, they were visible only as dark sweeping silhouettes that blocked out the distant stars.

The flight crew's anxiety never managed to infect the spectators. Intellectually, the spectators knew that ring crossings were one of the riskiest parts of the mission. They just didn't feel it. They'd survived a close pass by the sun, a crippling accident at the orbit of Jupiter that had killed one of their own and nearly ruined the mission, months in space far beyond the reach of the rest of humanity, and here they were. Deep in their emotional cores, they knew nothing would go wrong.

They were right. Nothing did go wrong. The ship took some minor hits from some minor bits of ice in the gaps. Nothing the structured foam hulls and carbon composite skeletons couldn't handle, and nothing that service egg jockeys couldn't repair once they were settled in.

Each pass through the potentially hazardous ring gaps came more quickly on the heels of the last. The first ring crossings were separated by a day and a half. Just before the Nixon finally settled into the inclined circular orbit that threaded the Maxwell Gap, the crossings were three and a half hours apart.

Then they were close.

- "What do we know?" Fang-Castro asked.

They were gathered in the Commons, which had been declared temporarily off-limits to anyone not invited-not because there were any secrets, but because there wasn't enough room for everybody who wanted to attend. The chairs were mostly occupied by the science crew, along with representatives from Navigation and Engineering. Sandy was recording the meeting, which was being transmitted directly back to Earth on an encrypted link.

"We're poking at it with everything we've got," said Barney Kapule, a ranging and surveillance expert, one of two on board. The two had been chosen for their expertise in operating the onboard telescopes and the associated cameras. Everything they saw in their scopes was on its way back to Earth within milliseconds.

What had appeared two years earlier to be idle speculation by Richard Emery, the vice chair of the Joint Chiefs of Staff, was close to spot-on.

"This is no moonlet," Kapule said. "Our primary object is the size of a minor moon, an oblate spheroid a good five kilometers in diameter." He tapped his slate and a vid of the object popped up on the oversized Commons vid screen. "It has minimal perturbing effect on the rings, so it has to be very low in density. In other words, we think it's hollow, so it's not a natural object. Whether it ever was a natural object, we don't know yet. The surface is irregular. At this distance, we can't tell if it's natural weathered material, you know, roughened up by occasional small impacts over the years, or an artificial shell with a lot of hardware stuck on the outside."

"Why can't we see it better?" John Clover asked.

"Because it's dark-not exactly stealth-black, but the surface is very, very dark, shading to a lighter gray at both of the poles," said Candace Frank, Kapule's associate. She touched her slate and brought up a different view of the object. "Whether or not this was intentional camouflage, it made the primary difficult to pick out in the Maxwell Gap as anything more than a minor moonlet. But it is more, a lot more. Not only do we have the primary, but it has a substantial retinue of dozens of additional moonlets, considerably less than a hundred meters in size. They appear to orbit in a fixed formation with the primary, and statistically there's no possibility that the formation is natural. They were placed where they're at. Whether they're physically connected or just station-keeping, we can't tell at this distance, but they're all associated with each other."

"In other words, we don't have one alien object, we got a whole bunch of them," Fang-Castro said.

"Even more than we've been talking about," Kapule said. A new view came up, one that seemed sprinkled with salt. A group of thin red rings popped up, surrounding each white grain. "We're seeing hundreds, and maybe thousands, of pixel-sized glitters of light that move between the primary and its moonlets and out into the rings and back again. Whatever they are, they're always moving, like a swarm of bees around a hive . . . not to suggest anything invidious here."

"What are the patterns?" Fang-Castro asked. "Is that a defense system?"

"Yes, we have an analysis," said Don Larson, the mathematician and former founder of the orgy club. "To go back to the bee metaphor, it's more like they're gathering honey and bringing it back to the nest, rather than performing any kind of defensive maneuvers. They're not particularly fast . . . fast enough, but not way fast . . . and their actions are deliberate, rather than random. Even if not designed for defense, they could certainly be used that way. To see them at this distance must mean that they are some meters in diameter. If they are metallic, and if enough of them hit the Nixon as quickly as they are moving now, they could tear us apart. It'd be like being hit by cars driving at highway speeds. In other words, they seem to be gathering honey, whatever that is, but like honeybees, they could bring out the stingers."

Fang-Castro shook her head. She wanted none of that. The Nixon was not an armored warship.

Over the next several days, the steady minuscule thrust of the Nixon's engines gradually warped its orbit, changing its inclination until the Nixon was orbiting within the Maxwell Gap in the plane of the rings. Simultaneously, they crept up on the alien constellation. Navigation and the surveillance people fed a steady stream of vid to the computers, where image analysis software tracked the motion of each of the bees. Sophisticated statistical modeling looked for any changes in the pattern of their collective motions, any indication that they were responding in any fashion to the approaching spaceship.

From Earth, they got a steady stream of essentially useless speculation about the nature of the constellation: the scientists on the Nixon saw everything hours before the earthbound analysts, and by the time their speculations got back to the ship, it had all been thought of.

Fang-Castro said to Crow, quietly, "David, the politicians and the military seem strangely quiet."

"By design, I think," Crow said. "Almost anything they say, the Chinese would pick up, one way or another. Not the encrypted stuff, but just chatter in the hallways. Which tends to be fairly accurate, if you're in the right hallway."

None of the analysis picked up changes in the behavior of the alien artifacts. The bees appeared to be as oblivious to the presence of humanity in the solar system as the starship had been two years earlier. Still, the Nixon held back, stabilizing its position at three hundred kilometers from the constellation. This was plenty close for the Nixon's best telescopes-they could see ten-centimeter details on the alien facilities and the bees.

And they launched two recon shells, basically small, slow rockets equipped with cameras and designed to be extremely visible to radar and even visual detection, the better to signal peaceful intentions. The recon shells did a complete loop around the station, broadcasting a three-hundred-sixty-degree view of it.

They watched for a day. The nature of most of the bees became apparent, although the ultimate purpose of their activities was still mysterious. Most were ice-catchers. They hunted for ring debris. Some of them looked for chunks of ice comparable to their own size, latched onto them with grapples, and hauled them back to one of several moonlets. Others had large scoops and swept up ice gravel and sand, the way a whale scooped up plankton. This was also ferried to the moonlets. Another much smaller group of bees shuttled containers of some kind between the moonlets.

None of the bees seemed to be equipped with armaments, not even so much as a cutting laser. The same seemed to be true of the moonlets and the five-kilometer primary. The surfaces were mostly natural rock, porous regolith dotted with various alien assemblages that were mostly unrecognizable. A few were clearly antennae of some kind or another; none looked anything like a beamed energy or projectile weapon. The constellation seemed to be entirely unarmed.

The primary rotated slowly with a period of four hours, further evidence of its artificial nature. A natural moon this close to Saturn would've been tidally locked, just as Earth's moon was to its parent planet.

At Fang-Castro's command, the Nixon moved closer, then paused again. During the primary's second rotation, after the move, the Nixon's computers spat out an anomalous delta.

A previously jet-black spot on the surface of the primary had turned light gray. During the third rotation things began to get genuinely weird. The black spot was now bright white and surrounded by concentric rings in rainbow colors. When the polychrome target came over the horizon on the fourth cycle, it was glowing dimly.

As the primary's rotation brought it around toward the Nixon, the glow brightened and coruscated until it could be seen with the naked eye through the windows of the Nixon, sparkling in the distance like a glass crystal spinning on a string and catching the sun.

The glow began to fade again after the target passed the median line until it was almost extinguished by the time the target had rotated past the horizon.

The fifth rotation repeated the light show of the fourth. The message was clear: "We know you're here."

Who or whatever "we" meant.

- Naomi Fang-Castro took slow, shallow breaths and sipped her tea as her most senior crew members took their seats for the morning briefing, chatting with each other, making last-minute slate checks. Her face was calm, peaceful in its thoughtfulness.

That was entirely for show.

Aliens were no longer a distant, hypothetical consideration, not with Nixon parked next door to the primary. When everybody was settled, she put down her cup, and the chatter ended; the crew had learned early on that this was the signal that the meeting was about to begin.

"We're skipping the usual status reports," Fang-Castro said. "Have them recorded before dinnertime. I assume everything is nominal. Our sole business this morning is to decide on our next move. John, what's your take on what we know?"

Clover put down his triple-strength espresso, put his fingertips together, and said, "They're inviting us over for coffee and Danish."

"This is being recorded, John, so . . ."

"I'm somewhat serious. Look at their behavior . . . and lack of it. They take no apparent notice of us until we settle into our position. They keep doing business as usual. There's no evidence of weaponry or hostility. The colored lights are not in any apparent way a warning. We don't know what those colors mean in their culture, obviously-white is for mourning in Korea, black is for mourning in the West-but it seems likely that given the colors they've chosen, which they probably know are attractive to us, they're inviting us in, rather than warning us away."

"Where does that conclusion come from?" asked Martinez. "That those colors are attractive?"

"Our astronomers have done an analysis of the colors, and they are quite pure, they are very specific wavelengths-there's nothing in the UV or IR ranges, as though they were spattering us with everything. That suggests that they know what wavelengths we see, and that . . . give me a little rope here . . . suggests that they may very well know which ones we like," Clover said. "So we show up, but we do nothing. Eventually, they take the initiative. They set up a pretty little light show, designed to catch our eye, and just in case we're really thick, it shines brightest when it's pointed directly at us. Then they sit back and wait. How could that not be taken as an invitation?"

Imani Stuyvesant, the exobiologist, waved a stylus. Fang-Castro nodded at her. "Are you sure? Maybe that is the wavelengths they see best. Or maybe they don't even see the patterns the same way we do. Honeybees and birds see flowers a lot differently than we do."

Clover smiled and tapped his fingertips together. "If you were talking about human equivalents, Imani, you could be right. But aliens, I'd say it's pretty much guaranteed that they won't see exactly the way we do. There are all kinds of animals on Earth that don't see exactly the way we do. What would be the odds that the alien sensory apparatus, their eyes, would respond anything like ours? The astronomers and physicists started taking measurements like mad when it began"-Clover nodded companionably toward Bob Hannegan-"and all they saw was visible light. No other kinds of radiation. It was tailor-made for our eyes. The light show was purely for our benefit.

"So I just gotta figure, if they know that much about our physiology, they have some idea of how we respond to stimulus. The word that came to mind when I saw that display? Pretty. It was a sparkly, colorful, enticing bit of eye candy. It was presented to us the way we'd hang a shiny bauble on a string and hold it up before a baby, just to get the kid to reach out for it. You really think that was coincidence? Or miscommunication?"

Clover continued: "Remember, they could have been looking at our TV shows for a century. Beings who could build these artifacts and travel between stars almost certainly have some sense of curiosity, or self-preservation. If they could see our TV signals, they surely would have at least looked at them. Any analysis of our TV signals would tell them a lot about us: not just the culture, but our level of tech and everything else. Everything we do winds up on TV."

Martinez raised a stylus: "What if it's a deliberate trap?"

Clover shrugged. "Could be, but why go to the trouble? They can build starships that use antimatter for fuel. If they wanted to smack us upside the head, it's not like there's much preventing them from doing so. Why play games? It's like the question of why they didn't accelerate an asteroid into the earth, to wipe us off the face of the planet. They could, but they haven't. That suggests they don't want to."

Fang-Castro pulled the argument back in. "If the aliens are intentionally deceiving us, I don't think there's anything we can do about it. That's the bottom line. So we can sit out here and dither, or we can go in. We keep watching and analyzing, of course, but we're not going to turn around and head home." She allowed herself to show a bit of a smile. "So, I agree with John that we've received an invitation to reach out. We are going to reach. I won't risk ship-critical personnel in the first team we send to the primary. Unless anyone has a relevant objection, I will assign Captain Barnes to command the first contact team. He has combat command experience and is also heavily trained in combat trauma medicine. His second will be Lieutenant Emwiller, for the same reasons. Bob Hannegan and Imani Stuyvesant will cover physics and exobiology, John Clover will see to the cultural issues, Sandy Darlington to make the record. Ms. Fiorella will probably try to assassinate me for not including her in the trip, but I'm afraid she'll have to wait. Sandy, your first duty will be documentary, but if you should have a moment to make some vid that Ms. Fiorella can use, I'm sure she will appreciate it."

"I will keep those priorities in mind," Sandy said.

"Good. Do that." Fang-Castro turned to Martinez and said, "Joe, I'm sorry, but you're not on this run." His face fell. "Next to Dr. Greenberg, you are the single most vital person to keeping this ship running. If things work out as we hope, you'll have plenty of future opportunities, but for this expedition I want you to pick one of your assistants, whoever has the most experience flying a bus."

"Elroy would be good for it. He's good in space and has a lot of on-the-spot creativity, and I know he's anxious to get out there."

"Done, then. Tell Mr. Gorey." She looked around the room, which included several members of the contact team. "I want you all to be ready to go in six hours. Do what you need to get ready. I would suggest naps. And, Mr. Crow?"

"Yes?"

"I believe you'll find Ms. Fiorella out in the hall. Disarm her, and send her in."

Rested and equipped, but not fed-they were uncertain about the availability of alien restrooms and although some facilities were built into the EVA suits, nobody enjoyed using them-the exploratory team assembled in the air lock of the storage and shuttle bay. The bay could be pressurized for shuttle maintenance and other on-site activities, but normally it was left open to space.

The seven-person party, led by George Barnes, a marine captain, suited up. The short-range shuttles, designed to carry up to twelve people and convey a substantial amount of cargo, were boxy skeletal affairs, similar in size and shape to double-decker omnibuses, so, naturally, that's what they got called.

Barnes was soft-spoken and meticulous. Sandy had always been a bit suspicious of marines during the Tri-Border fight, as they seemed willing to trade casualties for easy movement. That is, they used lighter weapons than Sandy thought reasonable. Faced with a Guapo hardpoint, they'd tend to do recon with a live patrol, then attack with backpacked munitions. The army would check it with drones of various kinds, both fliers and crawlers, and once the extent of the hardpoint was determined, the army had no qualms about calling in the air force with thousand-kilo bunker-busters, or toasting the place with a fuel-air heater.

On the other hand, good marine officers were just plain good officers, and Barnes was affable enough. Along with Sandy, Barnes taught a couple of popular physical-fitness courses.

As Barnes hand-checked the readouts on all seven suits, he took a call from Fang-Castro. "Captain Barnes, your party will be enhanced by one extra member. She'll be there in a couple of minutes."

"Yes, ma'am. Who is it?"

"One guess."

Fiorella showed up two minutes later, still pissed. "I imagine you set Fang-Castro straight," Sandy joked on a private channel.

Fiorella bared her teeth.

Sandy said, "Seriously, did you pee before you left? You have a bladder the size of a thimble."

"Yes. I peed. Now shut the fuck up."

"Keep your teeth off your lip-you won't be able-"

"Shut up."

"I gotta tell you one more thing, before you tell me to shut up again."

"Tell me."

"I brought the mini-Red with a Post-it pad. You can stick it to the bus rail and focus it on your face as we go out, and talk to it on a side channel. When we get back, we can intercut your commentary with the documentary photos."

"Sandy . . . but wait. You knew I was coming?"

"No, but I've been exposed to your powers of persuasion," Sandy said. "I suspected I might be seeing you."

"Sometimes I think you're brighter than I give you credit for," Fiorella said. Pregnant pause. "But only sometimes."

- The Nixon's buses weren't pressurized. The upper deck was equipped with seats and harnesses and umbilical connectors for space suits that provided life support, power, and communications. The suits were comfortable; they'd been designed to be lived in for up to thirty-six hours. They'd support a human being for longer than that, but things would start to get ripe. Food, water, waste elimination, air recirculation, were provided for. A built-in sponge bath, not so much.

The suits even offered entertainment: the heads-up virtual screen could show movies, vids, reading material, even games, whatever the wearer had uploaded into the suit databanks, or had transmitted to it. None of the team had bothered uploading data for this trip; boredom seemed unlikely to come up inside Saturn's rings, with the vast delicately colored expanse of Saturn itself hanging to one side and aliens awaiting them.

Beneath the seats, the life-support system sat on top of an open framework equipped with grapples, maneuvering actuators, and tie-downs. The front of the bus was equipped with manipulator arms, like the claws on a lobster. At the rear end of the bus were the rockets. The bus "cruised" at a maximum ten kilometers a minute, a snail's pace by the standards of space travel, but entirely sufficient for the bus's normal operating range of a thousand kilometers.

The first trip to the alien constellation's primary would be an easy half-hour run, and over that distance, fancy orbital mechanics didn't come into play: Gorey could fly it by the seat of his pants.

The five-kilometer primary was impossible to miss if you knew where to look; it was dim and dark, but it was twice the size of the full moon. When they were loaded, strapped in, checked one last time by Barnes, Fang-Castro gave them the go-ahead.

Barnes said, "Mr. Gorey. You've got the wheel."

The bus unlatched from the ship, Gorey gave it a tiny boost to the left, pointed it slightly inboard of their alien objective, and opened the engines. The bus's quarter-gee acceleration brought them to their cruising velocity in barely over a minute; it felt oppressively heavy to people who'd been living in a tenth of a gee for half a year.

Hannegan, the physicist, said, "My God, when we get home, it's gonna hurt, the gravity is."

"That's why you've got to keep coming to the PE classes," Barnes said. "If you don't, going home won't just hurt, it'll kill you."

Sandy kept his high-resolution cameras running all the way in, with the recordings retransmitted to the Nixon as they were made. Gorey stopped the bus ten kilometers out. Fang-Castro asked, "Anything?"

"Not that I see," Barnes answered.

They'd agreed that purely passive reconnaissance was the safest course. No laser altimeters or radar-mapping, nothing beamed at the alien structure, nothing that could be interpreted as hostile or invasive. They thought they'd been invited . . . but what if they were wrong?

The bus trip had been timed so that they'd arrive shortly before the primary's rotation brought the rainbow target in line with the Nixon. The scientists had wanted the bus to loop around the primary, so that they'd have a minutely detailed record of its entire surface, but Fang-Castro had vetoed the idea. The bus would never be out of sight of the Nixon, not on the first trip.

Barnes: "Here comes the target."

As the alien sphere turned, the rainbow target slowly appeared, brightening and sparkling but now something new happened. A hundred meters off to one side of the rainbow, a new, smaller bull's-eye target began to glow, in repeating concentric rings of yellow, green, and blue that shrank toward the center and disappeared.

Barnes: "John, is that a landing port?"

Clover said, "Can't see what else it could be."

Barnes said, "Admiral, unless you object, I'm going to have Elroy take us in. Otherwise, we'll be waiting another four hours before you're line-of-sight with us."

"I concur," Fang-Castro said.