Sisko frowned and wished he'd taken Dax up on her offer. He'd forgotten how cloyingly sweet the Kai could be when she wanted someone's help. Biting his lip, he considered all she'd told him.

"So this plague," he said out loud, filling his office with his voice, "began with a bunch of replicators?"

"That's the information I've just received," Winn replied calmly. "Mind you, these replicators were not distributed by the government. They were obtained through the most illegal of channels."

"In any case, you're saying that the disease has spread," the captain continued. "Apparently through the water supply, when some of the dying animals polluted it." She nodded. "Apparently, yes."

"And the whole population is threatened," he concluded.

"That's correct," the Kai replied. "Our immunologists tell us we could face annihilation in a matter of weeks."

She might as well have been talking about the weather in the capitol the day before. However, Sisko sensed an urgency in her that she didn't normally display. The average Bajoran might not have noticed it, but he did.

The captain stroked his goatee. "I'm sorry, of course, that this has happened. We'll help in any way we can."

Winn smiled politely. "Good. I knew the Emissary would come to our aid. Otherwise, why would the Prophets have singled you out?"

Sisko shifted in his chair. He'd never been comfortable with the religious identity bestowed on him by the Bajorans.

By all accounts, he'd been the first to communicate with the beings they called the Prophets -- the creators of the quadrant's first stable wormhole -- and certainly he'd made an interesting first contact. But by his reckoning, he was still just a man.

"Exactly what would you like us to do?" he asked.

The Kai heaved a sigh. "There is so much that needs to be done, I hardly know where to start. Of course, our main goal is to identify the virus and devise a cure. No doubt, your Dr. Bashir has more expertise in such matters than our simple Bajoran scientists."

"Dr. Bashir is a brilliant man," the captain agreed. "Nonetheless, what you're asking for is a tall order, Kai Winn -- especially within the time frame you've described."

Winn shrugged. "If it was easy, Emissary, we would have accomplished it ourselves."

Sisko grunted. "Yes, I suppose you would have. Very well, I'll get Bashir working on it. And Dax as well."

"I am grateful," the Kai remarked. "And I am also relieved, because I know you will not fail me."

He looked at her. "The Prophets told you this?"

She returned the look. "Do you have any doubt of it?"

The captain didn't answer her question. He simply said: "We'll do our best. Can I escort you back to your vessel?"

"That won't be necessary," Winn told him. "I know the way." And with that, she got up from her chair and exited his office.

As he watched her go, he felt himself shiver. It was the way he always reacted when he brushed up against something slimy.

Sisko tapped his communications badge, establishing a link with all the other badges on the station. "Major Kira, I need to see you. And bring Odo with you."

"Is there a problem?" asked his first officer.

The captain bit his lip again. "I'm afraid there is," he told her. "I'll fill you in when I see you."

A pause. "We'll be right there," Kira replied.

Sisko shook his head. He wasn't looking forward to telling the major that her whole race was in danger of extinction.

The Bajorans had fought so hard -- and endured so much -- to throw off the yoke of Cardassian rule. It would be a terrible and ironic shame if they were to succumb to a vicious little bug.

In her office, Kira Nerys studied the pictures of the replicator that Kai Winn had provided. She sifted through them, shaking her head and muttering to herself.

"Something wrong, Major?" came a voice from behind. She turned to see Chief O'Brien behind her. He had a box of tools in his hand.

"Just working on a problem, Chief." Her eyebrows puckered into a question. "And you?"

"You complained your office was too cold last week, remember? I thought I'd check it out for you."

"Oh, right. Fine." She paused a moment and then extended a picture to him. "What's your opinion of this?"

He took the picture and gave it a glance. "Not particularly good composition. It's slightly out of focus, and pardon me for saying so, but it should be more centered..."

"I mean of the equipment pictured there, Chief," Kira said patiently.

"Oh." He paused a moment and then shrugged. "Standard replicator model Twenty-One-A. Not exactly state-of-the-art, but a real workhorse. Newer models tend to break down faster. They don't make them like this anymore."

"No one ever makes anything like they did anymore, Chief. At least, that's what I've noticed." She took the picture back and said, "Apparently, it was acquired through the black market."

O'Brien let, out a whistle, but then said, "I guess I shouldn't be surprised. You can get anything on the black market, it seems."

"Yes," Kira agreed, "but as near as we can tell, this caused some serious problems. It cooked up some kind of virus that's..."

Her voice trailed off as she saw O'Brien's look. That was when she realized and remembered. "By the Prophets -- your family's down there."

O'Brien nodded speechlessly and then found his voice. "We've got to get them back up here."

"We can't," Kira told him regretfully. "There's a quarantine on Bajor. No one can come out of there." She hesitated, looking for something to say. "Chief, I wouldn't worry--"

"You wouldn't worry? With all due respect, Major, it's not your wife and daughter down there!"

"No, but it's not as if I don't have friends or family there," Kira said sharply, "and they're Bajoran. So far, it seems we're the only ones affected. To the best of our knowledge, any humans down there are perfectly safe. All right?"

She wasn't sure if he'd even heard her. "Major," he said quickly, "if it's all the same to you..."

Kira nodded. "You'd like to adjust my office temperature later, I know. Right now you want to get a call in to your family to make sure they're okay." She waved him off. "Go, go. It's all right. Just get back here before icicles start to form on me."

"Will do," said O'Brien, and he quickly bolted from the room.

Kira sighed. Then she scanned the images of the pictures into the computer. "Computer," she said, "study the images I've just placed into memory and search for any serial numbers or indications of previous ownership."

The computer went to work, and Kira leaned forward, waiting for the results.

Dr. Julian Bashir peered at a series of screens to the left of his research station, where additional clinical data from Bajor was displayed as it was received. He drummed his fingers nervously on his control panel.

Each screen charted a different bio-sign for the population already exhibiting symptoms of the disease. One dealt with respiration, another with heart rate, a third with temperature, and so on. There were details regarding the illness's effect on musculature and nervous system.

The work was remarkably exacting, considering the panic that must have been spreading all over the planet's surface. But then, he reminded himself, the Bajorans were nothing if not dedicated.

Turning to another screen, the doctor regarded the Bajoran blood sample that had been transported to the station not half an hour ago. Though the sample itself stood under strict quarantine in an electromagnetic construct in the lab next door, Bashir had the feeling it was right in front of him.

An adversary, he thought. And a horrific one at that.

The virus, like all viruses, was basically a helix of DNA. But in this case, it was dark purple and -- considering it was without sentience or volition -- strangely malevolent-looking, as it floated in a sea of Bajoran blood. While he watched, it invaded a stray skin cell, piercing the cell wall with ease.

The white blood cells that clustered around the entry point did so in vain. They were clearly of no use against the virus.

In a matter of just a few hours, the doctor knew, the invader would force the healthy cell to expend its energies in the creation of another helix -- a twin to the first one. And as the first cell collapsed, spent, the second helix would go on to invade a second cell. The process would be repeated, then repeated again, on and on....

Until the host body was so ravaged it couldn't help but succumb. A grisly end, to be sure.

And there was nothing exactly like the virus in his files, which included the sum total of the Federation's medical knowledge. The thing was a stranger, an anomaly.

Bashir turned to Dax, who was sitting at the other end of the infirmary, charting the spread of the disease across the face of Bajor. Though her back was to him, he could see the results of her work.

Against the greens and browns of Bajor's topography, a number of bright orange lights dotted the map. The greatest cluster was around the Paqu village, where the first outbreak seemed to have occurred. However, as the graphic showed only too well, every continent was now infested with the telltale orange spots.

No surprise there. Bajorans preferred face-to-face contact to electronic communications, so they traveled around their globe more than people on other worlds.

"Jadzia?" he called.

Dax didn't turn around. She just sat there with her back to him.

"Jadzia?" he called again.

Still no answer.

Getting up, the doctor traversed the infirmary and took up a position by the Trill's shoulder. He leaned forward, to get a better look at her.

What he saw took him by surprise. Dax's eyes were red-rimmed, almost welling with tears. And her mouth was a thin hard line.

"Jadzia?" he repeated softly.

Finally her eyes shifted toward his. There was a faraway look to them for a moment. Then they came into focus.

"Julian?" she said. She blinked a few times. "Sorry about that. I guess I wandered off for a second there."

Eyes narrowing with concern, Bashir nodded. "Are you all right?"

The Trill managed a smile. "I'm fine. Just a little tired maybe." She rubbed her eyes.

"You can take a break," he advised her.

Dax shook her head. "No," she said emphatically. "Now where were we?"

"I was about to ask you if you'd seen any changes in the spread of the disease. Pockets of resistance, perhaps."

Returning her attention to the map, she considered it for a moment. Then she gave her response. "No change at all -- though I wish I could say otherwise."

The doctor sighed. "I know what you mean."

Dax looked up at him. "How's the culturing going?"

Bashir shrugged. "We won't know for a few hours yet."

He was in the process of producing samples of the virus for testing -- a hundred samples, to be exact. Like the original sample he'd received from Bajor, they were in the lab next door.

"In a way," he continued, "it's a good thing that the virus grows so quickly. If it were slower to reproduce, the creation of test samples would have taken a lot longer."

The doctor eyed his friend. "You're sure you're all right?"

Dax dismissed him with a backhanded motion. "Go," she told him. "I'm fine. Really."

He went back to his work, but he could tell there was something bothering her -- distracting her. He didn't have to look far for an explanation, either.

The Trill had always been a compassionate person. And she had made a great many friends among the Bajorans since her arrival on Deep Space Nine.

All that misery on the planet had to be affecting her. Ravaging her emotions. Playing havoc with her concentration.

It disturbed him greatly that it should be so. If he was going to come up with a cure for the virus, he would need Dax operating at her best. Her scientific expertise would be invaluable in the hours and days to come.

"Me?" said Quark, working up all the innocence he could.

Odo glared at him from the other side of the polished synthewood bar. He leaned across, so that his face was just inches from the Ferengi's.

"I wouldn't be surprised," the shapeshifter growled.

Quark held his hands out in an appeal for justice -- a gesture he'd practiced before a mirror as a boy. "Constable, I had nothing to do with those faulty replicators. And that's the truth."

"You wouldn't know the truth if it walked into your bar and reserved a holosuite." Odo lifted his chin. "And don't call me 'Constable.' I don't like it."

The Ferengi made a show of being hurt. "You like it well enough when Captain Sisko calls you 'Constable' -- and I've known you a lot longer than he has. Why, I remember when I first arrived on the station--"

The shapeshifter stopped him with a raised hand. "Don't try to change the subject," he advised. "As you say, I've known you a long time. Now, as I recall, we were talking about replicators -- and your involvement with them."

"Or lack thereof," Quark insisted, wagging a peremptory finger. "I'm telling you, this is the first I've heard about it."

"I find that hard to believe," said Odo. "No one's better connected to the black market than you are."

"Nonetheless," the Ferengi told him, "it slipped by me somehow."

He wasn't particularly pleased about it, either. It meant there was new competition out there -- competition he hadn't even identified yet.

That was bad. That was very bad.

He didn't need to consult the Rules of Acquisition to know he had to do something about it. And quickly, before he lost his reputation as the sector's most resourceful businessman. After all, reputation was everything.

The shapeshifter was scowling, his eyes narrowed as he sized Quark up. "You're not lying about this, are you? Someone really did effect this transaction without your knowing about it."

"That's what I've been trying to tell you." The Ferengi leaned a little closer to Odo. "Just out of curiosity, what are you planning to do about it?"

The shapeshifter's scowl softened a bit. "I'm not quite sure, to be honest. One way or another, it's my job to find out how those replicators made their way to Bajor -- and if you're not involved, it's going to make that job a great deal more difficult."

"Especially since there's a new player in the game," Quark remarked.

Odo looked at him. "In other words, if it was one of the usual suspects, you would have known about it."

The Ferengi shrugged. "Something like that."

The shapeshifter grunted. "Well, if you hear anything, I trust you'll let me know."

"I will indeed," Quark assured him.

With a last wary glance over his shoulder, Odo threaded his way past the paying customers and out of the bar. As the Ferengi watched him go, determination took hold of him.

After all, it was in his own interest to find out who had dealt those replicators to Bajor. He vowed to expose the unprincipled swine who was muscling in on his territory, one way or the other.

"Not the replicators?" Sisko echoed.

"That's correct," said Dr. Bashir. He looked at the others assembled in the captain's office -- specifically, Dax, Kira, Odo, and O'Brien. "I was leary of that conclusion as soon as I heard it. After all, replicators can't create stable lifeforms -- not even on the cellular level, to my knowledge."

"Then where did the virus come from?" inquired Odo.

"Good question," said the doctor. He held up a medical tricorder. "I had the opportunity to analyze a sample of the raw matter supply that came with the replicators -- using an electromagnetic shield, of course, to prevent contamination of the station." He frowned as he turned to Sisko. "Apparently, it was the matter itself that carried the virus."

The captain took the tricorder and went over the data displayed on it. "I don't get it," he replied. "Are you saying that whoever gave Paqu village the replicators... wanted to inflict a virus on Bajor?"

Bashir shook his head from side to side. "I don't think so. More likely, the virus was dormant and undetectable, even to the smugglers. They probably had no idea what they were carrying."

"And then the replication process woke the buggers up," O'Brien suggested. "Is that what you're saying, Doctor?"

Bashir nodded. "That's what I'm saying, Chief. If the raw matter had been subjected to a Federation-level inspection, the virus would have been detected and the population could have been protected from it. But seeing as how smugglers don't bother with such details...."

His voice trailed off ominously. Not that he had to finish -- judging from everyone's expressions, they all got the picture.

"What about a vaccine?" asked Dax. "Are they having any luck?"

"No more than before," the doctor informed her. "Basically, they're tinkering with broad-based vaccines that have proven effective elsewhere. But this virus has so far resisted everything they've thrown at it."

"Have they continued with... quarantines?" Kira suggested, her voice quavering ever so slightly.

"Already in place," said Bashir, albeit reluctantly. "In Paqu village and wherever else there's been a concentration of cases." He gazed sympathetically at the Bajoran. "I'm sorry, Major. I know the thought of your people penned up like lab subjects cannot be a pleasant one."

"To say the least," breathed Kira, suddenly finding something interesting to look at on the bulkhead.

Obviously, thought Sisko, she was taking this thing pretty hard. And why not? This wasn't some race she'd had to think of only in the abstract. The Bajorans were her people. They were her blood. "Maybe if we knew where the virus came from," O'Brien proposed, "we'd have a better idea of how to deal with it."

"Good idea," the doctor confirmed. "As a matter of fact, Jadzia's already done some work along those lines."

Dax nodded. "The theory was that if we traced the raw matter trail far enough back, we might find someone who's come up with a cure for the virus -- or at least a way to slow the spread of it. Or, failing that, we might gain some insight into the type of environment it grew up in -- so we can experiment with its reaction to adverse conditions."

"And?" the captain prompted.

"I matched up the observed symptoms with those recorded in the computer's medical logs," the Trill explained.

"Don't tell me the Cardassians had a hand in this," O'Brien interjected. His brow creased. "Or worse yet, the Dominion..."

Odo frowned at the suggestion. He was obviously uncomfortable with the fact that his people, the Dominion's "founders," were perhaps the biggest threat to the Federation in its history.

"No," Dax responded. "Nothing like that. As it happens, this particular set of symptoms has shown up in four sectors of space. Two were within the Federation, one in the Gorn Hegemony, and one in Orion space."

"One of the instances in the Federation was on Vulcan," Bashir told them. "But we can rule that one out, since Vulcan blood is so different from the Bajoran variety. The other instance was on Cabrius Prime -- but we can eliminate that one as well."

"Why is that?" asked Kira.

The doctor smiled grimly. "Cabrius Prime was destroyed in a supernova some thirty-five years ago. There's no life there, viral or otherwise."

The major grunted. "Sorry I asked."

"What about the other two possibilities?" Sisko asked.

"The Gorn case," said the Trill, "turned out to be a dead end as well. It seems their problem wasn't a virus at all, but a subtle form of radiation poisoning. When they eliminated the radiation leak, the symptoms went away."

"That leaves the Orions," observed Odo.

Bashir nodded. "So it does. I'd say there's a good chance that's where the virus came from. Especially when you consider the Orions' predilection for smuggling and other illegal ventures."

"But the Orions aren't a single unified population," Sisko reminded them. "They're spread out into several large factions and a great many smaller ones, separated by space and allegiances and cultural differences. In short, knowing the Orions are the culprits only gives us a starting point."

"In other words," said Kira, "we need to know which Orions."

"That's right," the captain agreed. "And there are only two ways to find that out. One is to try to determine who on Bajor has ever dealt with Orions -- or might have considered it." He looked to his first officer.

"I'm on it," Kira assured him.

"So am I," said Odo.

"And the other way?" asked Dax.

"The other way," said Sisko, "is one we'll hold in abeyance -- in case the first way doesn't work."