Luther was the Alabama-born son of a well-loved black minister, and he had inherited his father's gift for bestowing comfort.

"There's no question about it, Bill," Luther had said. "You go home to your wife. You tell Houston they'd better send the limo to get you, or they'll have to deal with me." How different from the way Diana had reacted. Ever logical, she had calmly pointed out that there was nothing Bill could do to speed his wife's recovery. Debbie was comatose, she wouldn't even know he was there. As cold and brittle as the crystals she grows her lab, was what Bill thought of Diana.

That's why he was puzzled that she was now asking about him.

She hung back in the node, as remote as always. Her long blond hair waved about her face like drifting sea gra.s.s.

He turned to look out the window again. "I'm waiting for Houston to come into view," he said.

"You've got a new batch of E-mail from Payloads." He said nothing. He just stared down at the twinkling lights of Tokyo, now poised at the knife edge of dawn.

"Bill, there are items that require your attention. If you don't feel up to it, we'll have to split up your duties among the rest of us." Duties. So that's what she had come to discuss. Not the pain he was feeling, but whether she could count on him to perform his a.s.signed tasks in the lab.

Every day aboard ISS was tightly scheduled, with little time to spare for reflection or grief. If a member was incapacitated, the others had to pick up the slack, or experiments went untended.

"Sometimes," said Diana with crisp logic, "work is the best thing to keep grief at bay." He touched his finger to the blur of light that was Tokyo.

"Don't pretend to have a heart, Diana. It doesn't fool anyone." For a moment she said nothing. He heard only the continuous background hum of the s.p.a.ce station, a sound he'd grown so accustomed to he was scarcely aware of it now.

She said, unruffled, "I do understand you're having a hard time. I know it's not easy to be trapped up here, with no way to get home. But there's nothing you can do about it. You just have to wait for the shuttle."

He gave a bitter laugh. "Why wait? When I could be home in four hours."

"Come on, Bill. Get serious."

"I am serious. I should just get in the CRV and go."

"Leaving us with no lifeboat? You're not thinking straight." She paused.

"You know, you might feel better with some medication. Just to help you get through this period."

He turned to face her, all his pain, all his grief, giving way to rage. "Take a pill and cure everything, is that it?"

"It could help. Bill, I just need to know you won't do something irrational."

"f.u.c.k you, Diana." He pushed off from the cupola and floated past her, toward the lab hatchway.

"Bill!"

"As you so kindly pointed out, I've got work to do."

"I told you, we can divide up your duties. If you're not feeling up to ita""

"I'll do my own G.o.dd.a.m.n work!" He drifted into the U.S. Lab. He was relieved she didn't follow him. Glancing back, he saw her float toward the habitation module, no doubt to check the status of the Crew Return Vehicle.

Capable of evacuating all six astronauts, the CRV was their only home should a catastrophe befall the station. He had spooked her with his mutterings about hijacking the CRV, and he regretted it.

Now she'd be watching him for signs of emotional meltdown.

It was painful enough to be trapped in this glorified sardine can two hundred twenty miles above earth. To also be watched with suspicion made the ordeal worse. He might be desperate to go home, but he was not unstable. All those years of training, the psychological screening tests, had confused the fact Bill Haning was a professionala"certainly not a man who'd ever endanger his colleagues.

Propelling himself with a practiced push-off from one wall, he floated across the lab module to his workstation. There he checked the latest batch of E-mail. Diana was right about one thing, Work would distract him from thoughts of Debbie.

Most of the E-mail had come from NASA's Ames Biological Research Center in California, and the messages were routine requests for data confirmation. Many of the experiments were monitored from the ground, and scientists sometimes questioned the data they received. He scrolled down the messages, grimacing at yet another request for astronaut urine and feces samples. He kept scrolling, and paused at a new message.

This one was different. It did not come from Ames, but from a private-sector payload operations center. Private industry paid a number of experiments aboard the station, and he often received E-mail from scientists outside NASA. This message was from SeaScience in La Jolla, California.

To, Dr. William Haning, ISS Bioscience Sender, Helen Koenig, Princ.i.p.al Investigator Re, Experiment CCU#23 Archaeon Cell Culture Message, Our most recent downlinked data indicates rapid and unexpected increase in cell culture ma.s.s.

Please confirm with your onboard micro ma.s.s measurement device.

Another jiggle-the-handle request, he thought wearily. Many of the orbital experiments were controlled by commands from scientists on the ground. Data was recorded within the various lab racks, using video or automatic sampling devices, and the results downlinked directly to researchers on earth. With all the sophisticated equipment aboard ISS, there were bound to be glitches. That's the real reason humans were needed up herea"to troubleshoot the temperamental electronics.

He called up the file for CCU#23 on the payloads computer and reviewed the protocol. The cells in the culture were Archaeons, bacterialike marine organisms collected from deep-sea thermal vents.

They were harmless to humans.

He floated across the lab to the cell culture unit and slipped his stockinged feet into the holding stirrups to maintain his position. The unit was a box-shaped device with its own fluidhandling and delivery system to continuously perfuse two dozen cell cultures and tissue specimens. Most of the experiments were completely self-contained and without need of human intervention.

In his four weeks aboard ISS, Bill had only once laid eyes on the tube 23.

He pulled open the cell specimen chamber tray. Inside were twenty-four culture tubes arrayed around the periphery of the unit.

He identified #23 and removed it from the tray.

At once he was alarmed. The cap appeared to be bulging out, as though under pressure. Instead of a slightly turbid liquid, was what he'd expected to see, the contents was a vivid blue-green.

He tipped the tube upside down, and the culture did not shift. It was no longer liquid, but thickly viscous.

He calibrated the micro ma.s.s measurement device and slipped the tube into the specimen slot. A moment later, the data on the screen.

Something is very wrong, he thought. There has been some sort of contamination. Either the original sample of cells was not pure, another organism has found its way into the tube and has destroyed the primary culture.

He typed out his response to Dr. Koenig.

Your downlinked data confirmed. Culture appears drastically altered. It is no longer liquid, but seems to be a gelatinous ma.s.s, bright, almost neon blue-green. Must consider the possibility of contaminationa He paused. There was another possibility, the effect of microgravity. On earth, tissue cultures tended to grow in flat sheets, expanding in only two dimensions across the surface of their containers. In the weightlessness of s.p.a.ce, freed from the effects of gravity, those same cultures behaved differently. They grew in dimensions, taking on shapes they never could on earth.

What if #23 was not contaminated? What if this was simply how Archaeons behaved without gravity to keep them in check?

Almost immediately he discarded that notion. These changes were too drastic. Weightlessness alone could not have turned a single-celled organism into this startling green ma.s.s.

He typed, Will return a sample of culture # 23 to you on next shuttle flight. Please advise if you have further instructionsa"

The sudden clang of a drawer startled him. He turned and saw Kenichi Hirai working at his own research rack. How long had he been there? The man had drifted so quietly into the lab Bill had even known he'd entered. In a world where there is no up or down, where the sound of footsteps is never heard, a verbal greeting is sometimes the only way to alert others to your presence.

Noticing Bill's glance, Kenichi merely nodded in greeting and continued with his work. The man's silence irritated Bill. He was like the station's resident ghost, creeping around without a word, startling everyone. Bill knew it was because Kenichi was insecure about his English and, to avoid humiliation, chose to converse little if at all. Still, the man could at least call out "h.e.l.lo" when he entered a module to avoid rattling the nerves of his five colleagues.

Bill turned his attention back to tube #23. What would this gelatinous ma.s.s look like under the microscope?

He slid tube #23 into the Plexiglas glove box, closed the hatch, and inserted his hands in the attached gloves. If there was any spillage, it would be confined to the box. Loose fluids floating around in microgravity could wreak havoc on the station's electrical wiring.

Gently he loosened the tube seal. He knew the were under pressure, he could see the cap was bulging. Even so, was shocked when the top suddenly exploded off like a champagne cork.

He jerked back as a blue-green glob splatted against the inside of the glove box. It clung there for a moment, quivering as alive. It was alive, a ma.s.s of microorganisms, joined in a matrix.

"Bill, we need to talk." The voice startled him. Quickly he recapped the culture tube and turned to face Michael Griggs, who had just entered the module. Floating right behind Griggs was Diana. The beautiful people, Bill thought. Both of them looked sleek and athletic in their navy blue NASA shirts and cobalt shorts.

"Diana tells me you're having problems," said Griggs. "We just spoke to Houston, and they think it might help if you considered some medication. Just to get you through the next few days."

"You've got Houston worried now, have you?"

"They're concerned about you. We all are."

"Look, my crack about the CRV was purely sarcastic."

"But it makes us all nervous."

"I don't need any Valium. Just leave me alone." He removed the tube from the glove box and returned it to its slot in the cell unit. He was too angry to work on it now.

"We have to be able to trust you, Bill. We have to depend on each other up here."

In fury, Bill turned to face him. "Do you see a raving lunatic in front of you? Is that it?"

"Your wife is on your mind now. I understand that. Anda""

"You wouldn't understand. I doubt you give your wife much thought these days." He shot a knowing glance at Diana, then launched himself down the length of the module and into the connecting node. He started to enter the Lab module, but stopped he saw Luther was there, setting up the midday meal.

There's nowhere to hide. Nowhere to be alone.

Suddenly in tears, he backed out of the hatchway and retreated into the cupola.

Turning his back to the others, he stared through the windows at the earth. Already, the Pacific coast was rotating into view.

Another sunrise, another sunset.

Another eternity of waiting.

Kenichi watched Griggs and Diana float out of the lab module, each propelled by a well-gauged push-off. They moved with such grace, like fair-haired G.o.ds. He often studied them when they weren't watching, in particular, he enjoyed looking at Diana Estes, a woman so blond and pale she seemed translucent.

Their departure left him alone in the lab, and he was able to relax. So much conflict on this station. It unsettled his nerves affected his concentration. He was tranquil by nature, a man content to work in solitude. Though he could understand English enough, it was an effort for him to speak it, and he found conversation exhausting. He was far more comfortable working alone, and in silence, with only the lab animals as company.

He peered through the viewing window at the mice in the animal habitat, and he smiled. On one side of the screened divider twelve males, on the other were twelve females. As a boy growing up in j.a.pan, he had raised rabbits and had enjoyed cuddling them on his lap. These mice, however, were not pets, and they were isolated from human contact, their air filtered and conditioned before they were allowed to mix with the s.p.a.ce station's environment.

Any handling of the animals was done in the adjoining glove box, where all biological specimens, from bacteria to lab rats, could be without fear of contaminating the station's air.

Today was blood-sampling day. Not a task he enjoyed, because it involved p.r.i.c.king the skin of the mice with a needle. He murmured an apology in j.a.panese as he inserted his hands into the gloves and transferred the first mouse into the sealed work area. It struggled to escape his grasp. He released it, allowing it to float free while he prepared the needle. It was a pitiful sight to watch, the mouse frantically thrashing its limbs, attempting to propel itself forward.

With nothing to push off against, it drifted helplessly in midair.

The needle now ready, he reached up with his gloved hand to recapture the mouse. Only then did he notice the blue-green blob floating beside the mouse. So close to it, in fact, that with of a pink tongue, the mouse gave it an experimental lick. Kenichi laughed out loud. Drinking floating globules was something the astronauts did for fun, and that's what the mouse appeared to be doing now, playing with its newfound toy.

Then the thought occurred to him, Where had the blue-green substance come from? Bill had been using the glove box. Was whatever he'd spilled toxic?

Kenichi floated to the computer workstation and looked at the experimental protocol Bill had last called up. It was CCU#23, a culture.

The protocol rea.s.sured him that the globule contained nothing dangerous.

Archaeons were harmless single-celled marine organisms, without infectious properties.

Satisfied, he returned to the glove box and inserted his hands.

He reached for the needle.

July 16

We have no downlink.

Jack stared up at the plume of exhaust streaking into the azure sky, and terror knifed deep into his soul. The sun was beating down on his face, but his sweat had chilled to ice. He scanned heavens. Where was the shuttle? Only seconds before, he had watched it arc into a cloudless sky, had felt the ground shake the thunder of liftoff. As it had climbed, he'd felt his heart with it, borne aloft by the roar of rockets, and had followed its path heavenward until it was just a glinting pinp.r.i.c.k of reflected sunlight.

He could not see it. What had been a straight white plume was now a jagged trail of black smoke.

Frantically he searched the sky and caught a dizzying whirl of images.

Fire in the heavens. A devil's fork of smoke. Shattered fragments tumbling toward the sea.

We have no downlink.

He woke up, gasping, his body steeped in sweat. It was daylight, and the sun shone, piercingly hot, through his bedroom window.

With a groan he sat up on the side of the bed and dropped his head in his hands. He had left the air conditioner off last night, now the room felt like an oven. He stumbled across his bedroom to flip the switch, then sank down on the bed again and breathed a sigh of relief as chill air began to spill from the vent.

The old nightmare.

He rubbed his face, trying to banish the images, but they were too deeply engraved in his memory. He had been a college freshman when Challenger exploded, had been walking through the dorm lounge when the first film footage of the disaster had aired the television. That day, and in the days that followed, he'd watched the horrifying footage again and again, had incorporated it so deeply into his subconscious that it had become as real to as if he himself had been standing in the bleachers at Cape Canaveral that morning.

And now the memory had resurfaced in his nightmares.

It's because of Emma's launch.

In the shower he stood with head bowed under a pounding stream of cool water, waiting for the last traces of his dream to wash away. He had three weeks of vacation starting next week, but he was a long way from being in a holiday mood. He had not taken out the sailboat in months.

Maybe a few weeks out on the water, away from the glare of city lights, would be the best therapy. him, and the sea, and the stars.

It had been so long since he'd really looked at the stars. Lately it seemed he had avoided even glancing at them. As a boy, his eyes had always been drawn heavenward. His mother once told him that, as a toddler, he had stood on the lawn one night and up with both hands, trying to touch the moon. When he could not reach it, he had howled in frustration.