FAILURE ANALYSIS

INTRODUCTION

Shortly after the space station Terok Nor became Deep Space Nine, the Bajoran Wormhole was discovered, which could serve as a passage to the Gamma Quadrant. It was not long before exploration of the Gamma Quadrant began.

The events described in this story pertain to a disaster occurring during one of the early exploratory missions to the Gamma Quadrant.

PROLOGUE

Stoan slipped out of his daytime attire and donned a comfortable robe. He entered a small chamber adjacent to his bedroom and made himself comfortable on the floor cushions. The lights in the room dimmed automatically. He began his meditation. As was Stoan's practice, he would meditate before taking his evening meal.

Stoan practiced daily meditation in part to cope with the daily difficulties of life on Earth. It was a time to mull over the events of the day, to extract what had been learned, to identify what needed to be done, to put all of the day's events into their proper places. Stoan did not apply the traditional Vulcan meditation techniques he'd learned in his youth, as he found traditional techniques to be too restrictive. He had developed his own techniques, and practiced them faithfully.

As he entered a state of enhanced mental clarity, his meditations first settled on a recurrent concern. Like most Vulcans living on Earth, Stoan found the planet to be a disturbing place. Most of those living on Earth were Humans, and Humans were difficult to understand. They were civilized, yes; but they were prone to act based upon the flimsiest of evidence and upon defective or corrupted reasoning.

His mindframe settled, he directed his thoughts to the events of the day. Stoan held a Chair in Advanced Engineering Studies at Starfleet Academy, and this semester, he taught a course in Advanced Safety System Design. Earlier today, his students presented their preliminary approaches to his third design problem, and he had offered his critiques. The problem pertained to designing a system that safely conveyed a hazardous liquid from a holding tank to a mixing receptacle, while meeting various constraints as to size, materials, moving parts, fluid variability, and system accessibility. Designing a successful system that could convey a fluid was a fairly simple matter, but designing a system that could convey a hazardous liquid was not quite so simple. In Stoan's problem, the system had to withstand a variety of disturbances, both natural and unnatural. Thus, the students not only had to design a system that could move the fluid, they had to design a system that was robust and safe even if things went horribly wrong. If any fluid should escape, students were told, sentient beings would die. In the laboratory, the deaths of these sentient beings would be hypothetical. But in the reality of the universe, system failures might result in actual, real, permanent deaths.

The students needed to understand that.

And they would understand it, for they were learning from the best teacher. Failure Analysis and Safety were Stoan's specialties. He was the foremost expert on those subjects in the Federation. As Stoan often reflected, to say he was the foremost expert was not a boast; it was a statement of fact.

Stoan remembered that, as a younger man, he had found the Vulcan Science Academy too dictatorial, and he and some friends had opted to further their education in Engineering by attending Starfleet Academy. Stoan found the Academy programs challenging, and he excelled. He took courses in Failure Analysis, which were widely recognized as some of the most difficult courses in the entire Academy. He completed the courses with a perfect score. No cadet had accomplished such a thing before, and no cadet has done such a thing since.

To say so was not a boast, Stoan reminded himself. It was a statement of fact.

When he became commissioned as an ensign, Stoan had been assigned as an assistant engineer on the USS Josef Knoba. Stoan believed that he had earned grades that justified a more prestigious assignment, but he accepted his assignment without complaint. The Chief Engineer of the Josef Knoba, a Human named Lieutenant Commander Zhang, was a capable engineer, but Stoan knew he was better. Though Stoan was certain he had never said anything disrespectful to Zhang, Zhang entered in Stoan's fitness reports that Stoan had "continuing problems with attitude and demeanor." Such remarks, which in Stoan's view reflected more on the mindset of his superior officer and less on his own performance as an engineer, nevertheless impeded Stoan's chances for advancement. Stoan knew he was being treated unfairly, but he said nothing. He attained the rank of lieutenant, but his promotion came later than Stoan believed it should have. Stoan considered requesting a transfer.

Stoan recalled how he had been rescued from the Josef Knoba by one of his former Academy professors. Tray Amblin was one of the Academy's civilian educators, and she had taught one of the Failure Analysis courses in which Stoan had excelled. She had been tasked by Starfleet to improve the safety systems used for particular transfer shuttles. There had been several system failures in recent years, resulting in numerous injuries and at least one death. Solving the problem of system safety was a challenging one, and Amblin felt she would be up to the challenge, if she could have the assistance of her brightest student, Stoan.

Stoan was not content in his position with the Josef Knoba, and he earnestly wished to work with Amblin. Starfleet was reluctant to let Amblin have him, however. Some at Starfleet thought a compromise could be reached, in which Stoan would work for Amblin and would also covertly report on Amblin's progress on the project. This was a prospect that Stoan found distasteful. Rather than be a spy, Stoan resigned his commission as a Starfleet officer and went to work for Amblin as a civilian. It was an unusual action to take, and some in Starfleet complained mightily, but it worked out for the best. Amblin and Stoan designed the new safety system in a matter of weeks, simulated it, tested it, refined it and presented it to Starfleet for approval. Starfleet engineers tried to make the new system fail but could not. Thereafter, the new safety system was installed on nearly all of the ships in the fleet capable of receiving transfer shuttles.

The number of system failures dropped to zero.

For Stoan, this was just the beginning. He designed—or in some cases, redesigned—safety systems for airlocks, radiation containment, transporters, weapon instrumentation, weapon management, prisoner safety, gravimetric pods, hatchways, environmental suits, and multi-phase energy diverters. Some of these he designed with Amblin, but most he designed himself. In one of his most famous accomplishments, he designed a new safety system for cleaning the residue traps that were present in some older warp drive engine systems. Previously, cleaning the residue traps was deemed "ultra-hazardous" and had to be done at a qualified starbase by trained Starfleet personnel using specialized equipment. After Stoan's safety system was in place, cleaning the residue traps was no longer "ultra-hazardous," and within a year it became "routine." His reputation as a safety engineer soared.

In his meditation, Stoan performed a calculation that he often performed. By making reasonable estimations and assumptions, he could conclude to a high degree of certainty that that his designs of safety systems had saved the lives of numerous sentient beings. In his present calculation, the number of sentient beings whose lives he had saved exceeded 75,000. These sentient beings would have perished, had his systems not been in place. To say so was not a boast; it was a statement of fact.

When Starfleet Academy offered Stoan a professorship in the Department of Engineering, Stoan accepted. He refused, however, to accept the title of "Professor." Although he was well-qualified in advanced studies, he likewise refused to accept the title of "Doctor," thinking such a title was best reserved for those who practiced the healing arts. Other the years, he earned the right to other titles, but he considered them to be inaccurate, pretentious, conflicting, or otherwise unnecessary. He insisted that his students address him as "Mister Stoan."

His classes were some of the most difficult in the Academy.

In addition to his work as a teacher, Stoan found time for occasional work on safety systems, usually for Starfleet operations. At the present time, he had no such ongoing projects. His work was exclusively focused upon his Advanced Safety System Design course. He was passing on his expertise to his students.

Stoan's mind turned briefly to the students of his who were Vulcans. In this semester, there were two. They of course knew how to pronounce his name correctly. The other students typically pronounced his name as "Stone." Stoan tolerated the mispronunciation, which was indeed very close to being the proper pronunciation, though still not strictly correct. He noted that most non-Vulcans seemed to lack the aural sensitivity needed to identify the subtle tonal distinctions, and he knew it would be a fruitless exercise to try to correct any mispronunciations.

Stoan's meditation had made his mind free of impediments to reasoning, and he turned his focus to the work his students had done. The students' approaches to the hazardous liquid problem varied. None of the approaches was foolhardy, yet none was foolproof. Stoan assessed the approach that seemed least likely to succeed as "posing numerous practical difficulties." He called the most impressive approach "promising."

All of his students were smart. But Stoan understood that mastering safety and failure analysis are not merely a matter of intelligence. A good safety system design has to account not just for accidents, but also for malice, for stupidity, for sabotage, for incompetence, for the expected and for the unexpected. Stoan tried to impress upon his students that system failure can come from so many sources. A designer must try to imagine all possible sources of failure, and then design the system to deal with them.

This was not an easy thing.

His Vulcan students seemed to have the most difficulty with it. For one thing, they had a hard time grasping why other beings might perform actions that were manifestly illogical, and why designs must account for nonsensical behavior. Their rational points of view could make them blind to scenarios that might be irrational or idiosyncratic.

Stoan was reminded that he had realized in his first days at the Academy was that there was a difference between intelligence and cleverness. Intelligence involved knowledge, comprehension, organization of information, and ability to relate one fact to another. Cleverness was different. It involved innovation, an ability to look at things in new and unconventional ways, a propensity to see things that an intelligent observer might miss.

From his interaction with Humans, Stoan understood that some fools could be quite clever.

And so Stoan's students had been instructed to consider not only what was supposed to happen, but what foreseeably could happen. If sentient beings acted intelligently and sensibly and carefully and skillfully all the time, many safety systems would be unnecessary. But sentient beings do not always act so, and it is up to a system designer to identify all the different ways in which things might go wrong.

And on this point, Stoan meditated nearly every day.

His mind was clear. His intellect was focused. His body was relaxed. Upon comparing the students' various proposed solutions to his problem, he concluded that most of them had done quite well. Indeed, some of the students had come up with ideas that seemed to be better than the ones he had developed himself.

Stoan began sorting in his mind through the ideas he'd heard during the day, separating the better from the more problematic, combining elements from one proposal with elements from another, when a tone sounded, indicating an incoming audio-visual message.

While Stoan was in meditation, incoming messages were supposed to be blocked.

Except in cases of emergency.

Stoan brought his consciousness out of mediation and ordered, "Open communication."

His eyes remained closed for the moment.

"Mister Stoan," said the caller. Stoan recognized the voice immediately. It belonged to one of the few Humans who would make an effort to pronounce his name correctly.

"Yes, Commissioner Young," replied Stoan, opening his eyes. Commissioner Lorna Young's unsmiling face was on a display in front of him.

"Please activate security on your end."

Stoan checked an indicator and touched a control pad. "My side of the conversation is now secure," he said. He noted that the security level on the conversation was at the highest level.

"We have received word of an accident aboard the USS Observer. The preliminary report is that one of the probes exploded while aboard the vessel. There are numerous fatalities."

Stoan was astonished, but his face did not show it. The Observer was a specialized science survey ship for which Stoan had designed some of her most important safety systems. One of the goals of those safety systems, perhaps the most important goal, was the probes carried on the ship, though they could be explosive, ought not to explode in the proximity of living beings. Included within this goal was the objective that the probes carried on the ship should not explode while still inside the ship.

What Commissioner Young was telling him was that a system he had designed had failed catastrophically.

"Has this report been confirmed?" Stoan wanted to know.

"Not yet."

"Where did the explosion occur?"

"It occurred in the Gamma Quadrant. The ship has since returned to the Alpha Quadrant, however, and is currently near a Federation starbase, Starbase Deep Space Nine. We are told that all security, quarantine, confinement and preservation protocols are in place."

"Deep Space Nine is some distance away," Stoan commented. "It will take a considerable investment of time to assemble the Commission and to get there."

"Yes, it's a considerable journey. And there are several things we will need to do before we go there."

"Since it is extraordinarily unlikely that a probe exploded inside USS Observer, we should wait for confirmation before beginning our investigation and departing for the starbase. Do you agree?"

"Yes," sighed Young. "But Mister Stoan, based upon what we've heard from the commander of the starbase, I think you should expect that confirmation will be forthcoming."

The Commissioner promised him that she would contact him when she had further information, and then the communication was terminated.

Stoan could not accept what he'd heard as factual. He had designed the safety systems aboard Observer, and Observer's sister ship, Surveyor, himself. His mind had been well-ordered from his meditation, but this news had disrupted the clarity of his thinking. He could not conceive how a probe explosion could have occurred aboard Observer. There were a variety of safety systems to prevent that very occurrence. It was unthinkable that they all could have failed.

Stoan had even designed the systems so that even if they did all fail, no explosion would occur.

Stoan considered returning to meditation, but found his mind to be too disturbed by unanswered questions to make further meditation productive. He computed the probability that confirmation could be forthcoming, as Commissioner Young had predicted, and found the probability to be negligible.

But what if the report were confirmed? What if the news of an on-board explosion turned out to be true?

He would need more information. His mind could not reliably analyze the matter beyond that.

More likely than not, whatever information was obtained would show that the report from Deep Space Nine was in error. Stoan felt confident that it had to be in error. It had to be.

CHAPTER 1

Benjamin Sisko, Commander of Deep Space Nine, was in Ops. He was reviewing resource quality readouts when Lieutenant Jadzia Dax reported, "Someone's coming through the wormhole."

"Is anyone scheduled?" Sisko asked, thinking that the answer ought to be in the negative.

"No one is scheduled." Dax checked a readout. "It might be the Coronet, or the Observer. They're both expected back two days from now."

Sisko and Dax watched the Ops main display as the wormhole opened. The instant the wormhole opened, Dax's instruments came to life and her eyes went wide.

"Distress signal from that ship!"

The wormhole closed. A ship appeared in the blackness of space where the wormhole had been.

"Yellow alert," Sisko ordered. "What ship is that?"

"The Observer." Dax double-checked her sensors. "Verified, it's the Observer."

Oh, no, no, no, thought Sisko, instantly aware that what might happen next might be very serious. An immediate concern was that the residents of Deep Space Nine might react badly, knowing that Observer was in trouble and heading closer to the station. He was also immediately mindful that what was about to happen might well be a serious interstellar incident.

"Red alert!" Sisko barked. "Get Chief O'Brien up here, now! Alert Dr. Bashir!"

"Observer is hailing us," Dax reported, and immediately a stressed but controlled voice filled Ops.

"This is the USS Observer, Lieutenant Amy Pitts in command."

Sisko realized at once that if a lieutenant had taken command, then several higher-ranking officers must be unable to command. Whatever had happened, it was bad.

"Most of our crew is dead," Pitts's voice continued. "We have about twenty survivors."

Sisko shook when he realized that the crew of the Observer was over a hundred.

"Pitts! What is your status?" Sisko put as much authority in in voice as he could.

"We have experienced an on-board explosion; one of our probes has exploded!"

No, no, no, not that, Sisko thought, and then he reminded himself not to jump to conclusions. One thing at a time. "Are any of your other probes in danger of exploding?"

"I don't know. It's supposed to be impossible for them to explode on board."

Dax piped up. "Benjamin, minimum safe distance under such circumstances is 4,000 kilometers. They're at 10,000 and closing, fast!" Dax's voice had a touch of urgency in it.

"Observer! Pitts!" Sisko called. "Come no closer to this station than 5,000 kilometers! Acknowledge!"

"Acknowledged. 5,000 kilometers."

Dax monitored the Observer's moves. "Observer is slowing." Sisko looked over Dax's shoulder to verify it.

"Holding at 5,000 kilometers from your position," Pitts reported.

"Observer, stand by!" Sisko barked. "We'll beam your survivors over to our medical facilities."

"Julian reports he's ready to receive them," Dax said, just as Chief Miles O'Brien stepped off the lift and onto the floor of Ops. O'Brien tried to take in what was happening as he hurried to his post.

"Chief, I want you to handle this transport." Sisko pointed to the ship on the Ops display. "There are survivors on that ship. And we have been informed that there are many on that ship who did not survive. I want to you find all of the people with life signs and beam them to Dr. Bashir, immediately. Only the survivors, clear?"

O'Brien acknowledged the order with "Aye, sir," and began to activate the transporter with his controls. "Good God, is that the Observer?" The shock on his face was extreme when he realized what ship he was scanning.

"Yes. They are keeping station at 5,000 kilometers."

O'Brien was looking at the ship on the main Ops display. He seemed to have been rendered speechless. Sisko saw O'Brien's distress and couldn't help feeling some of that same distress himself. But there were things that needed to be done.

"Chief?! Get those people over here!"

"Aye, sir," O'Brien stammered, as he turned his attention to his instruments. "Sir, there are at least eighty people over there, dead. I've got sixteen survivors. Confirmed, sixteen individuals with life signs. Locking on. I'll transport them directly to the Infirmary."

"After you've transported the survivors," Sisko said, "I need to know this from you, Chief: Is the Observer in a safe condition or not? They say they've had one of their probes explode. They've got other probes aboard. I want to know whether any of those other probes might be at risk of exploding."

Things happened quickly. O'Brien transported the survivors to Deep Space Nine, and immediately began sensor sweeps of Observer. He reported to Sisko that the probes Observer carried appeared to be incapable of exploding. Sisko ordered confirmation that there was no risk of explosion, and he also ordered O'Brien to see whether he could confirm that the on-board explosion reported by Lieutenant Pitts was due to the detonation of a probe, as Pitts had said.

Sisko further ordered that the Observer be quarantined and preserved for investigation. Effective immediately, no one was to beam anything on or off the vessel. As a precaution, drones would be deployed around the Observer to scramble any transporter signals, to prevent anything from beaming onto or beaming off the ship. Deep Space Nine was placed under quarantine as well. All vessels approaching Deep Space Nine were to be directed away from the station, except in cases of emergency.

Observer was automatically holding its position 5,000 kilometers from the station, but Sisko directed Dax to have a tractor beam ready in the event that the relative positions of Observer and Deep Space Nine changed.

Sisko also ordered Dax to hail the starship USS Wild Rose, which had visited Deep Space Nine less than a day ago, and declare an emergency. When the Wild Rose's captain asked about the nature of the emergency, Sisko explained that he needed someone to make sure Observer remained under quarantine. Sisko assured the captain that his people had determined that there was no further risk of probe detonations. The captain was stunned, but agreed to return to Deep Space Nine and stand guard over Observer.

The Observer, Sisko knew, was full of many secrets. Sisko was determined that neither Observer, nor any of her secrets, was going to be stolen.

Word spread quickly around Deep Space Nine that the secretive USS Observer had returned to the Alpha Quadrant two days early. Observer had passed close by Deep Space Nine prior to her visit to the Gamma Quadrant, and at that time there had been some concern about a vessel having Upsilon Radiation-based devices approaching a starbase. Some residents of Deep Space Nine remembered that there had been a tragedy some years ago under somewhat similar circumstances, where many people had been exposed to Upsilon Radiation.

Fears about exposure had been allayed when Observer made its first pass by Deep Space Nine, but this time they could not be allayed. When word spread that Observer had suffered an explosion, the words "Upsilon Radiation" immediately came into play, and many aboard the station went into a state of panic.

Constable Odo found it difficult to maintain order aboard the station, but he and his personnel tried their best. It helped that, although the people aboard Deep Space Nine were agitated, they didn't want anything material and they were generally disinclined to acts of violence.

They simply wanted to be away from Deep Space Nine. They wanted to be evacuated, and evacuated now.

Sisko promptly amended his order that all vessels approaching Deep Space Nine were to be directed away. Emergency shuttles for evacuation to Bajor were permitted to come to the station.

Major Kira Nerys, Sisko's second-in-command, coordinated the evacuation efforts, working with the Bajoran authorities to bring the emergency shuttles to Deep Space Nine, to take away anyone who wanted to leave. Kira also arranged for relocation facilities to be set up on Bajor. The arrangement was hastily made and far less than ideal, but Kira thought it could be made to work, at least for a short time. Relocation was supposed to be temporary, and the Bajorans had supposedly run some drills and exercises addressing how Bajor would handle a rapid mass evacuation from Deep Space Nine.

With some exceptions, the station inhabitants that were in Starfleet were obliged to remain aboard the station; but all civilians were allowed to leave, and nearly all of them wanted to do just that. Families of Starfleet personnel were allowed to leave the station and find a safe place to stay, at least until this crisis was ended.

After the evacuation was well underway, Sisko made an announcement assuring the populace that the Observer was holding station at a thousand kilometers more than the minimum safe distance, and there was no danger to the station. This assurance counted for almost nothing in the views of most civilians. The exodus continued.

Sisko understood their fears. He insisted that his son, Jake, evacuate with some of the other Starfleet families, just as a precaution. Jake resisted, but he also knew his father could not be dissuaded.

Sisko talked to Kira about going with the evacuees to help them get temporarily settled, to help maintain order, and to help them return to the station when the danger had passed. Kira agreed that was a good idea. Sisko cautioned Kira that the station would be quarantined, so those who chose to leave would not be allowed to return until there had been a resolution of the Observer incident. He did not know how long that would be. Kira understood. She departed the station aboard one of the shuttles.

At Sisko's command, a secure message was dispatched to Commissioner Lorna Young, who headed the Commission on Specialized Planetary Studies, more commonly known as "the Commission." The Commission was the organization that oversaw the Gas Giant Mapping Project and that was responsible for the Observer's science missions. Sisko knew little about the Commission, except that it was the only entity in the known galaxy authorized to use Upsilon Radiation, and that it kept a low profile, with most of its actions being shrouded in secrecy.

Sisko's message to Young was brief. It reported that, according to the officer who brought the Observer back to the Alpha Quadrant, a probe had exploded on board. Sisko added that whether there actually had been a probe explosion on board was, at this time, unconfirmed. He wanted to include in the message only the things that he knew for certain, and not to include any speculation. Sisko reported that there were some survivors, and that they were receiving medical care, but that there were many dead still aboard Observer. He further reported that he had ordered that the Observer be quarantined, and that a Federation ship was being called in to stand guard. He added that he had ordered that the Observer's condition be fully preserved as in its current state, that the highest security protocols be implemented, and that the Observer was to maintain its position 5,000 kilometers away from the station.

A short time later, he received a secure reply. Commissioner Young's message was brief. She requested sensor sweeps of the Observer and also a report from the station's Chief Medical Officer as to the conditions of the survivors. She reminded him that all operations of the Observer were classified, and therefore no personnel should be involved with the Observer except for those having a high security clearance. Requests for such clearance would have to come through the Commission, she said.

Sisko groaned. The only one aboard Deep Space Nine he knew for certain had that level of clearance was himself. Dr. Bashir and Lieutenant Dax might also have clearance, or might be eligible to secure that level of clearance from the Commission, and probably Chief O'Brien could as well. They all had previous experience with secret Federation projects or operations. But there was no way the Commission would let Major Kira be involved with this, since she did not answer to Starfleet or to the Federation. It was just as well, Sisko thought, that she was attending to temporary relocation of station residents. Constable Odo would be staying aboard Deep Space Nine, but there was no way he'd be cleared to become involved with the Observer. For that matter, Sisko didn't know whether there were any other Starfleet officers under his command who might be able to obtain the requisite security clearance.

Sisko started to assemble the information that Commissioner Young requested. He spoke to Dr. Bashir first.

"How are the survivors?" Sisko asked.

Bashir was terse. "They're going to die within a matter of days. They've all received lethal doses of Upsilon Radiation."

"Are you sure?"

"Absolutely." Bashir's voice was icy. "No question about it, none at all. They are all in different stages of neural degeneration. The pattern is unique to Upsilon exposure."

"I see."

"And in all probability, there is nothing I can do about it."

"I understand. I know there is no known cure, no treatment."

Bashir scowled. "I doubt I'll be able to save their lives. But even worse, I very likely won't be able to relieve their suffering."

Sisko nodded. "I know. I know. Do the best you can."

From Bashir's demeanor, Sisko understood that Bashir's best would probably be futile.

Sisko then spoke to O'Brien. O'Brien actually had some positive news. "First, I can confirm that the Observer is safe. It is impossible for any of the other probes to blow up."

"Impossible? From the looks of it, it's already happened at least once!"

O'Brien understood the point. He reiterated his findings to emphasize his confidence: "I've verified the probes are now incapable of exploding, all of them. There is no chance that any of those probes could detonate. It is physically impossible. After the on-board explosion, all of the probes automatically broke their seals, and that basically turned the probes into hunks of junk. All of the potentially explosive components have been made non-volatile. The probes are designed to do that, I understand. Anyway, all of the volatile elements are now totally inert, and are permanently incapable of detonating. The Observer has exactly seventy-nine probes in its storage vault, which I believe is called 'the Locker.' I've scanned them all. Every single one. All seventy-nine are incapable of exploding."

Sisko wasn't quite reassured. "I wasn't certain you'd be able to scan the probes."

"As I understand it, sir, the Locker is shielded from sensor scanning under normal circumstances, and the probes have some shielding of their own. But if the probes are neutralized, as they are now, the shielding is dropped or otherwise made ineffective. Presumably the purpose is to show that the probes are indeed safe, so we can be comfortable being in proximity."

Sisko thought there might be another purpose. Sisko thought he'd heard that one circumstance that would cause the probes to become inert would be an attack upon the Observer by a hostile force. Anyone trying to disable the ship and steal a probe would find that the probe would be incapable of detonating, and therefore, useless. Dropping the shielding would show the attacker that the prizes were worthless and that there would be no point in pressing an attack to try to hijack them.

"Out of prudence, Chief, let's maintain the Observer at 5,000 kilometers."

"Aye, sir." O'Brien cleared his throat. "I have some additional things to report, unpleasant things. I have identified the remains of at least ninety-four people over there. It is difficult to determine an exact number. I don't know what we plan to do about them."

"Leave them there."

O'Brien swallowed. "Aye, sir."

"They'll be taken care of, Chief."

"I understand, sir. If I may recommend, we can remotely lower the interior temperature of the Observer to preserve their remains."

"Good idea. Do it."

"Aye, sir. Now, as for the explosion: there is no question that it took place in the Observer's Probe Preparation Bay. This is the place where the probes are prepared in advance of launch. The Probe Preparation Bay is in the lower aft part of the ship, just forward of the Locker. It is a highly secure area, and its shielding is still in place, so I cannot scan inside of it, but all of the bulkheads and decks surrounding the Probe Prep Bay are deformed, consistent with the pressure associated with an explosion inside the Bay. Further, I have scanned the rest of the ship and find no explosive damage anywhere else. So it looks to me that there was an explosion on board, and the explosion occurred inside the Bay."

Sisko was not surprised by that news. "That suggests very strongly that the thing that exploded was a probe." Sisko thought for a moment before speaking again. He decided O'Brien needed to know. "Dr. Bashir says that the surviving crew has been exposed to Upsilon Radiation."

O'Brien understood what this meant. "Then it was a probe, for certain. One of these probes blew up on board and unleashed Upsilon Radiation on its crew, the poor devils."

"Yes. That is what it looks like."

"I thought that wasn't ever supposed to happen."

"It wasn't."

"I mean, sir," continued O'Brien, "it was supposed to be impossible to happen."

Sisko sighed. "Maybe the word 'impossible' is a word we ought to avoid for a while. It was supposed to be impossible, but this accident did happen, so it clearly was possible."

"You're assuming it was an accident?" O'Brien wondered. "I'd be inclined to think that the explosion was intentional, caused deliberately. I've heard that there are hundreds of safety systems surrounding Upsilon Radiation; and if that's the case, I don't see how something like this could just happen."

"Right now, I'm not assuming anything."

"Yes, sir. What's our next step?"

"I need your sensor sweeps of the Observer. I'll send them, along with Dr. Bashir's report, to Commissioner Young, and we'll see what she wants to do."