Bashir gathered up Ezri’s limp form and carried her toward the medical bay at a full-out run. Bowers ran alongside, using his combadge to alert Ensign Richter to the emergency as they sprinted through the corridor and into the turbolift.

Moments later, Richter and Bowers were helping Bashir place Ezri’s feverish, perspiring body onto the table in the operating room adjacent to the main medical bay. Bashir dismissed Bowers with a curt nod. He was grateful for this room’s Earth-normal gravity as he unlimbered his medical tricorder and ran its scanner quickly across Ezri’s torso.

The readings were grim.

“What is it, Doctor?” said Krissten as she entered the chamber.

“Her isoboramine levels are falling steadily.”

As Krissten studied her own medical tricorder, apuzzled frown creased her face. “I’ve never seen anything like this before. Is her symbiont in immediate danger?”

“It certainly will be in another hour or two, if nothing changes in the meantime.”

“What could have caused this?”

Afraid that he already knew the answer, Bashir chose to dodge the question for the moment. “Trill physiology can be tricky, Krissten. Run a full battery of deep-tissue scans. We’ll laser-biopsy as necessary.”

“Aye, sir,” she said, then calmly set about her tasks. If there was one thing Krissten Richter had proved repeatedly over the past four years, it was that he could rely on her to keep her wits about her during a crisis.

Ezri’s eyes opened and she let out a long, forlorn wail. The sound pierced Bashir’s soul to its core. Above the biobed, a monitor confirmed that she was experiencing intense neurological trauma. Her nervous system was on fire, and he had no clue yet as to why.

“Get me the delta wave inducer,” Bashir said. “I want her unconscious.”

He pressed the wafer-thin device against Ezri’s temple, and she immediately relaxed. Her eyes closed and she grew quiet.

Please come back to me, Ezri, he thought as he lifted an exoscalpel from the instrument tray. He found himself staring at it as though he’d never seen it before. His hand felt unsteady, and recollections of his earlier near disaster with the instrument did nothing to calm him.

Don’t blame yourself, Julian, she had told him long ago, on a similar occasion. Back when she had been Jadzia Dax, and Verad Kalon had forced him to remove the symbiont from her body. Jadzia’s voice, weak and fading, spoke from his private citadel of memory: Don’t blame yourself, Julian. You did everything you could.

He forced himself to place that unhappy memory back on the high mental shelf to which he normally relegated such thoughts. He concentrated instead on trying to recall the particulars of every disease agent that might cause a spontaneous separation of host and symbiont. If one of these turned out to be the cause of Ezri’s condition, then a cure might already exist.

Hope buoyed him as he quickly adjusted his tricorder to look for particular genera of viruses and retroviruses.

Bashir’s combadge chirped before he’d completed a single pass with the device. “This is Merimark in the transporter room, Doctor.”

Damn!“Can it wait, Ensign?”

“’Fraid not, sir. Incoming medical emergency on the alien ship. I’m beaming possible wounded parties directly to the medical bay.”

“Acknowledged. Who’s coming?”

“It’s Nog and Shar, sir.”

When it rains, it pours, Bashir thought as he watched a pair of figures shimmer into view in the main medical bay chamber.

 

Bashir glanced toward Nog, who was propping himself up on his elbows, trying to get comfortable on the biobed. From his position, he couldn’t see the nearby bed on which Ezri lay unconscious.

Just as well, Bashir thought.

“I can’t believe this is happening,” Nog said, possibly for the hundredth time. He gritted his teeth as Lieutenant Candlewood checked the dressings on the stump of his left leg and made a quick tricorder scan of the rapidly healing—though still raw—wound that lay beneath.

Nog’s voice was flat and devoid of emotion. “I really can’t believe this is happening.”

Neither could Bashir. But the subject of Nog’s incredulity wasn’t his primary concern at the moment.

Ezri is.

She lay on the biobed between Nog’s and the one located in the medical bay’s farthest corner, on which the last of the convalescing aliens slumbered. Ezri’s breathing was ragged and shallow, and her pallor had increased hourly while she had drifted in an out of consciousness, confused and terrified during her few brief intervals of wakefulness. At least she was asleep at the moment, Bashir thought, without the need for the delta wave inducer. He was thankful for that one small mercy.

Krissten stood on the far side of Ezri’s biobed. “Dr. Bashir,” she whispered. “You’ve been…hovering for hours. Why don’t you get some rest? I’ll call you the next time she comes to.”

The medical bay doors hissed open before he could reply. Rubbing a weary eye with the palm of his hand, he turned toward the sound.

Commander Vaughn strode deliberately into the room, his craggy features solemn. Shar was at his side, his expression even more unreadable than usual, if that was possible.

Vaughn was first to speak. “Trying to communicate with the aliens has kept us a bit busy for the past few hours, Doctor. Sorry I haven’t had a chance to get down here before now.”

Bashir felt slightly muddled for a moment. Aliens? Then a glance at the long, spindly figure curled awkwardly on the third biobed brought him to alertness.

“Yes, of course, the aliens,” Bashir said at length. Now that he had released all of them except one, gravity in the medical bay had been adjusted back to its customary one gee, except for the immediate vicinity of the corner biobed. Krissten had made no secret of her delight at the return of Earth-normal gravity.

“Has anyone managed to translate their, uh, language yet?” Bashir asked.

Shar’s white dreadlocks, stark against his sky-blue skin, twirled slightly as he shook his head. “It’s hard to tell. But with Lieutenant Bowers and Crewmen T’rb and Cassini assisting me, I think we will manage it eventually. The alien text you downloaded may prove helpful in that regard after all.”

“Any change down here?” Vaughn said, looking in Ezri’s direction.

Bashir gazed at Nog and decided that any discussion of Ezri’s prognosis ought not to occur within range of the chief engineer’s sensitive ears. There was nothing to be gained by stressing him with bad news. Bashir gestured toward his office as Shar excused himself to speak with Nog.

“Give me the bad news first, Doctor,” Vaughn said, once the office door had closed discreetly behind him and Bashir.

“Ezri’s slipping away from us,” Bashir said. From me. He felt exhaustion suddenly gaining on him, with despair coming up hard on its heels. He sank heavily into the chair behind his desk.

“How?” Vaughn said, standing on the other side of the desk.

“There’s massive peritoneal inflammation in and around the symbiont pouch. As well as progressive neurotransmitter and endocrine imbalances, including toxic levels of thorocrine production.”

“Bottom line?”

“Ezri’s body is rejecting the symbiont. It’s happening very slowly, but there’s no denying it. And apparently no stopping it either. Her neurotransmitter production has fallen to critical levels, and her body is even rejecting direct isoboramine injections.”

“Isoboramine?” Vaughn said.

“It’s a neurotransmitter unique to Trills. Without a sufficient isoboramine concentration, the neural link between host and symbiont collapses, and the symbiont has to be removed in order to keep it alive.”

“Any clue as to what’s causing it?” Vaughn said, folding his arms.

Bashir shook his head. “All I can tell at this point is what’s probably not causing it. I can find no trace of any unusual virus or prion anywhere in her body. I tried a course of metraprovoline, lethozine, and metrazene, which will knock certain retroviruses out cold, even if we’d failed to detect them. No response. And I got the same results with the full spectrum of general antirejection drugs, the sort we ordinarily use on organ transplant patients. Neurogenics, for stimulating neurotransmitter production and uptake, have also proved to be a dead end. I even tried bethanamine.”

“Another neurotransmitter?”

“An inhibitor, actually. Bethanamine is a little-known Trill drug set which has been used occasionally to safely separate symbiont from host. But it failed to work on Ezri, for no reason I can fathom. In fact, nothing I’ve tried as yet has made very much difference at all. It’s as though her body is a computer running a program that can’t be altered once it’s started.”

“Could the Sagan’ s encounter with the alien artifact have anything to do with this?”

“I still can’t say for certain. All I know for sure is that Ezri’s isoboramine levels are still falling and the critical neuro-umbilical pathways between her and Dax are degrading. Net result: Her body is continuing to reject the symbiont. And I can’t stop it.” Bashir slammed his fist on the desk in frustration and then lapsed into silence.

From the back corridors of his memory, he heard the words of encouragement he had spoken to Jadzia after Verad had briefly taken possession of the Dax symbiont. You’re not going to die. Do you hear me? I’m not going to let you die. He tried not to dwell on his ultimate failure to deliver on his promise to Jadzia, a mere four years later. Or the fact that another such failure now appeared all but inevitable.

Vaughn’s impatient prodding brought him out of his reverie. “I said, ‘What’s next?’ Surely you’re not giving up, Doctor.”

Bashir shook his head, though he already felt utterly and completely defeated. “The symbiont appears to be exhibiting signs of incipient ischemic necrosis. As Ezri’s body continues to weaken, the symbiont is losing more and more of its vascular support. I’m afraid I’m running out of options.”

What I need is a miracle.

Vaughn seemed to turn that information over in his mind for several moments before speaking again. “How long does she have?”

“At the rate she’s producing rejection toxins, she might last a few more hours at the outside. That goes for the Dax symbiont, too, unless we remove it.”

Vaughn clearly was not ready to concede defeat. “All right. There are no other Trills on board, so transplanting the Dax symbiont is out of the question. Unless…”

“Sir?”

“What about placing her in stasis, symbiont and all?”

“A stasis field wouldn’t slow down the ongoing neural collapse. It might even hasten it.”

“All right.” Bashir could still hear a note of hope in Vaughn’s voice. “Trill symbionts have been implanted in humans from time to time, correct?”

Bashir nodded cautiously. “But only on a very temporary basis. Even if we’d started heading for Trill yesterday at maximum warp, the journey would still take weeks too long. And no Trill–human symbiosis could last long enough to keep the symbiont alive long enough.”

“Couldn’t we transfer the symbiont briefly into a series of different human hosts?”

“The hosts could probably tolerate that. But there’s no way the symbiont could. A series of marginal transplants like that would place far too much strain on it, without allowing for a sufficient refractory period. If the Dax symbiont is going to have any chance at all, it has to be returned to the Caves of Mak’ala on Trill, or the nearest equivalent, within a few hours of its removal from the host.”

Vaughn appeared to grasp the ramifications immediately. “And if the symbiont continues to weaken, you’re going to have to remove it from Ezri sooner rather than later.”

Bashir nodded. He felt hollow inside.

“So regardless of whether or not the Dax symbiont survives…” Vaughn trailed off.

“Barring a miracle, Ezri is going to die.” Bashir felt detached from himself as he spoke the words. There. I’ve finally said it out loud.

“You mentioned ‘the equivalent’ of the Caves of Mak’ala,” Vaughn said, stroking his beard, plainly still considering every conceivable alternative.

“Merimark and Leishman are already busy constructing a portable symbiont pool like the one I rigged to carry the Dax symbiont after Jadzia’s death last year. But there are still no guarantees. The symbiont has already become dangerously weak.”

Vaughn looked somber. “So you have a decision to make.”

Bashir found that he was having trouble maintaining his train of thought. He took a moment to compose himself before speaking. Perhaps fatigue was catching up with him. How long had he been awake?

“I can hold out for a miraculous last-minute cure for both Ezri and Dax,” he said. “Or I can give the symbiont a fighting chance at having another life.”

A life I’ll probably play no part in. For the first time, Bashir understood at a gut level how hard the earliest days of his relationship with Ezri must have been on Worf, the late Jadzia’s husband.

“At the expense of Ezri’s life,” Vaughn said. But Bashir could detect no reproach in the commander’s tone. Vaughn’s vivid blue eyes took on a faraway aspect that spoke eloquently of other times, other deaths, other unwilling but unavoidable surrenders to decay and entropy.

Vaughn placed a gentle, fatherly hand on Bashir’s shoulder. “I’m truly sorry, Julian.”

“So am I.” His words sounded banal in his own ears, but he could think of nothing better to say.

“How is Nog?” Vaughn said after a moment’s silence.

The doctor managed to summon a weak smile, actually grateful for the change of topic. It was a relief to put aside, however briefly, the crushing weight of the decision he carried on his shoulders.

“Let me show you,” Bashir said, leading Vaughn back into the main medical bay chamber and to Nog’s biobed. Shar stood beside the young engineer, who was sitting up and reading something on a padd. Vaughn failed to completely conceal his surprise when he noticed what lay on the low table beside the bed.

It was Nog’s left leg, severed at the knee.

“Hello, Captain,” Nog said, making as though to rise from the bed, then evidently realizing that the maneuver hadn’t been one of his best-considered ones. He gestured with his head toward the orphaned limb on the table, at which Shar was staring abstractedly.

“Sorry about this, sir. Shar has just brought me up to date on the repairs still going on aboard the alien ship.”

Vaughn appeared to be trying hard not to stare at Nog’s disarticulated leg, but was not entirely successful. “Between Shar, Senkowski, and Permenter, everything’s well in hand over there. You’ve already done most of the heavy lifting yourself.”

Shar nodded affirmatively to Nog. “I expect the alien vessel to be ready to get under way within a day or so.”

“You just rest and do whatever Dr. Bashir tells you,” Vaughn said to Nog. “Got it, Lieutenant?”

Nog looked sheepish as he handed the padd to Shar. Bashir caught a glimpse of technical schematics on its display screen just before it disappeared behind Shar’s back.

Bashir pointed to the leg. “Nog, may I?”

“Go ahead, Doc. Just bring it back when you’re through with it. I find it sort of comforting to have the thing around, now that it looks like I might not be needing it again.”

Bashir held the limb before him to allow Vaughn to examine it. Vaughn took it and turned it over and over. He appeared puzzled. Shar, however, who had brought Nog and his severed leg to the medical bay, seemed to be taking this in stride.

“What happened?”

“Nog’s body has apparently rejected it,” Bashir said, then allowed his words to sink in for a moment. Vaughn’s raised eyebrow made it plain that he, too, understood that bodily rejection was emerging as a common theme here. “And that’s not the end of it, either.”

“Son,” Vaughn said, handing the leg back to Nog. “What did you mean when you said that you ‘might not be needing it again’?”

Nog grinned as he lifted the coverlet that had been draped across his lap and slowly unwound the dressing from the stump of his left leg. As the bandages fell neatly away, Bashir looked at both Vaughn and Shar to gauge their reactions. Shar’s eyes widened slightly, his antennae probing unsubtly forward. Vaughn’s jaw fell like a nickel-iron meteor.

Bashir quickly examined the tiny, perfectly formed leg sprouting from Nog’s stump. It had grown by several centimeters during just the last hour.

Bashir wasn’t certain how much time had passed before the nonplussed Vaughn finally found his words. “Can you…explain this, Doctor?”

“At the moment, I’m simply at a loss,” Bashir said, shaking his head. “Even his burned femoral motor nerves are regenerating.”

“I’d be sorely tempted to call this a miracle,” Vaughn said, his gaze locking firmly with Bashir’s. “And wherever we find one miracle, we might do well to keep searching for others.” He was clearly talking about Ezri.

“I wish I could afford to believe in miracles, Captain,” Bashir said, biting his words off. “Unfortunately, I have to make do with the real world.”

The medical bay doors hissed open again. Merimark and Leishman entered, using antigravs to carry a meter-wide, half-meter-deep oblong container. The pair set the object down gently beside Ezri’s biobed.

“One medical transport pod suitable for a Trill symbiont,” Merimark said as she glanced uneasily at the unconscious Ezri. “Ready for activation when you give the order.” Bashir recalled that Kaitlin Merimark had become one of Ezri’s closest friends among the Defiant’ s current crew complement. It couldn’t be easy for her to see Ezri in her current condition.

“Thank you, Ensign,” Bashir said, then turned to Vaughn. “I’ll make a thorough investigation into Nog’s condition as soon as possible. But at the moment I’m afraid I’ve more pressing matters to attend to.”

Vaughn looked grave. “I take it you’ve come to a decision.” About Ezri went unsaid, though the words hung in the air like smoke over the Gettysburg battlefield.

“Yes. The only decision possible.”

“I understand,” Vaughn said. “Come on, Shar. Let’s get back to work.” Shar, his facial muscles suddenly unusually tense, nodded silently. Bashir wondered how much Shar knew about Ezri’s condition. He wished he had time to brief everyone beforehand about what was about to happen, and to allow Ezri to say her own farewells to one and all. But he no longer had that kind of time. He’d squandered that time with his repeated, fruitless attempts to save Ezri and the symbiont both.

Feeling miserable, Bashir watched Vaughn and Shar exit the medical bay.

He told himself that Ezri wouldn’t have wanted any maudlin good-byes. She’d have another life soon, once they returned Dax to the Trill homeworld after the conclusion of the Gamma Quadrant mission. She’d have plenty of time then to catch up with auld acquaintances, he thought.

“‘ ’Tis not too late to seek a newer world,’” Bashir said quietly to no one. Then he noticed Nog’s quizzical stare.

“What’s going on, Doc?”

Bashir realized that he had been protecting Nog from the truth about Ezri. He sighed, collected his thoughts, and said, “Nog, you deserve to know what’s really about to happen to Ezri.”

The only decision possible.

For perhaps the first time in his life, Bashir really, truly wished he were dead. “Ensign Richter,” he said. “Please prepare Ezri for surgery.” Then he turned back to Nog and started to explain, as gently as possible, that Ezri was going to die very soon.

The woman I love is going to die.

 

In preparation for the procedure, Ezri was moved back into the small surgical bay, where she slowly drifted back to consciousness. Her eyes opened and she smiled. Despite her pallor and fever, the smile made her as radiant as Bashir had ever seen her.

And it’s the last time. The last time I will ever see that smile.

His heart pounded, auricles and ventricles transformed to hammers and anvils. Doing his best to manage his roiling emotions, Bashir explained to her what was about to happen. She listened attentively and took the news with considerably more grace than Nog had. Or Merimark. Or even Krissten, for that matter.

But Ezri’s equanimity rattled him at first. He had to remind himself that Dax had already experienced host death eight times before.

“I understand, Julian. I love you. And I trust you to do whatever you have to do…to save Dax.”

Once again, he heard Jadzia’s voice, echoing up from a well six years deep: Don’t blame yourself, Julian. You did all you could.

He desperately wished he could believe those words.

“Julian.”

“Yes?”

“I don’t want to be conscious when you…cut the cord. Not like Curzon. That was different.”

Bashir knew that Curzon’s symbiont had been surgically removed as well. But that had been done at the end of a very long, very satisfying life.

“I understand,” Bashir whispered, his words catching in his throat.

“I don’t want to be…emptied, like the time Verad took the symbiont…” She trailed off. Bashir noticed for the first time that her face was wet.

Julian, Jadzia confessed in the back corridors of his mind. I’m scared.

“I understand,” he repeated. He felt a single fat tear roll down his cheek. Another one jostled for position behind it. He squeezed her hand gently. She squeezed back, hard. He bent down and brushed his lips against hers, then straightened and released her hand.

“I’m ready, Julian,” she said at length.

Blinking away his tears, he donned his surgical mask and lifted an exoscalpel from the tray beside the operating table. At his nod, Krissten carefully attached the delta wave inducer to Ezri’s temple.

“Ensign Juarez is standing by to activate the artificial environment container,” Krissten said in a subdued voice. After learning about Ezri’s condition, Edgardo demanded to be allowed back on duty, insisting his leg had healed sufficiently.

Ezri mouthed a silent I love you to Bashir, then smiled.

“Good-bye, Ezri,” he said.

Her lips curled into a faint smile. Then oblivion took her.

Responding to Bashir’s nod, Krissten activated the sterile field. He gripped the exoscalpel tightly in his gloved hand, grateful that the instrument showed no signs of slipping this time. Krissten silently opened the front of Ezri’s surgical gown, exposing Ezri’s abdominal pouch. Very gently, he moved the exoscalpel’s tip across her abdomen, leaving a slender crimson line in the instrument’s wake. A moment later, the body of the symbiont began to emerge, its brown, lumpy skin glistening under the room’s bright lights.

The symbiont inched forward, fairly oozing into his hand. After it had emerged entirely from Ezri’s body, Bashir cradled it gingerly. The eyeless, limbless creature’s helpless emergence reminded him of a cesarean section he had once performed; he had to remind himself this “baby” carried within it a store of experience and knowledge at least an order of magnitude greater than his own.

“This is going to be a somewhat unusual procedure,” Bashir told Krissten as he raised the symbiont slightly higher, studying the superficial patches of necrotic tissue that had already begun to appear along the moist, amber-colored umbilicus still connected to Ezri’s abdominal pouch. “There’s already been so much neural depolarization along the entire neuro-umbilical trunk that the nerve bundles will have to be cut in a specific order to minimize the risk of neuroleptic shock for the symbiont.”

“Understood,” Krissten said, her voice muffled slightly by her surgical mask.

“Neurocortical separator, please.”

She took his exoscalpel and replaced it with the requested implement. Gently hefting the symbiont in his left hand, he touched the tip of the compact, gleaming cylinder to a point about six centimeters down the length of the umbilical cord.

Ezri’s body jerked reflexively as the separator sank its tiny polyduranium probe into the cord. “Note that I have just severed the gross motor pathway nerve bundle,” Bashir said, his voice sounding flat and tinny in his own ears. He felt detached from his actions, as though he were a first-year med student watching with his classmates while a faculty member performed surgery in a Starfleet Medical operating theater.

He knew that he couldn’t proceed without that kind of detachment.

“The separator is now locking onto the fine motor bundles,” Bashir said, pressing on. Ezri’s fingers spasmed as the second nerve-fiber bundle separated. He withdrew the separator and closed his eyes for a moment.

I’m killing her. Just as surely as if I’d tossed her out an airlock.

“Symbiont vital signs are weak but holding steady,” said Krissten. “No sign of neuroleptic shock.”

Forcing his self-recriminations aside, Bashir opened his eyes and focused on the umbilicus with renewed concentration. Next, he severed the monopolar neurons that coordinated autonomic neurophysiological exchanges between Ezri’s and Dax’s nervous systems. Then he cut the redundant autonomic glial-cell pathways. He paused for a moment to recall the correct order: major, minor, and ancillary nodes. Yes, that was right.

Nearly done. God, let this be finished before I turn this thing on myself.

Next, the separator’s laser bit into the RDNAL organelle, a construct that consisted of a long tube buried in the very core of the umbilical’s complex bundles of nerve fibers. Moving nimbly, Bashir sealed the organelle on Ezri’s end of the umbilicus, which fell onto her abdomen like so much discarded ODN cable.

Jadzia’s voice haunted him once again. I’ve never felt so empty. He forced himself to ignore the memories—to ignore Ezri, who lay before him not quite dead, not quite alive, yet still gone forever.

“Note,” he said, “that the symbiont is now completely free of the host’s body. There’s been no change in the symbiont’s vitals.”

Krissten turned toward Nurse Juarez standing quietly by the door. “Edgardo, please ready the container.” Juarez approached the table, prepared to take the symbiont to the oblong receptacle which lay in the far corner of the room.

“Krissten, please prepare a hypo with twenty cc’s of isoboramine. I’m going to inject it directly into the symbiont’s end of the umbilicus.”

Krissten hesitated for a moment, then fetched the hypo and placed it in Bashir’s hand. She held the symbiont for him while he gently applied it to the tip of the umbilicus and pressed the plunger home. Bashir felt a wave of relief sweep over him as Krissten carefully handed the symbiont to Juarez, who in turn carried it toward the open, liquid-filled container in the corner.

Krissten turned back to Bashir, a question in her eyes.

“Yes?” Bashir said as he allowed his gaze to wander back to Ezri. He watched the gentle rise and fall of her chest, listened to the gentle sussuration of her breathing.

“We tried this drug before,” Krissten said. “But it had no effect. Why the second injection?”

Bashir gave his head a weary shake. “That was iso boramine, Krissten. This time I used boramine, which should stave off the symbiont’s growing necrosis and prevent delayed neuroleptic shock while it’s confined to the artificial environment.”

“No, Doctor.”

Bashir had never heard Krissten flatly contradict him before. He looked toward her and saw that her eyes had become immense. She appeared near panic.

“Excuse me, Ensign?” he tried to keep the irritation out of his voice, but didn’t succeed completely.

“Doctor, that injection wasn’t boramine. It was iso boramine.”

Bashir felt as though he’d been slapped across the face. “What?”

“That hypo contained thirty cc’s of isoboramine, sir. As you ordered.”

A realization colder than the winds of Trill’s Tenaran ice cliffs suddenly ran up his spine. Boramine. Isoboramine. Somehow, he had confused them. The two substances had similar names, obviously. But they differed from one another as much as oxygen did from fluorine.

And he knew that the consequences of mistaking one for the other could be every bit as serious.

Bashir watched as Juarez knelt beside the symbiont’s medical transport pod and prepared to place Dax inside its life-giving purple liquid bath. Juarez stopped in mid-motion, frowning.

He looked helplessly at Bashir and Krissten. “It’s…squirming.”

“My God,” Bashir said, rushing to the nurse’s side with a medical tricorder. He made a quick scan. “It’s an isoboramine overdose. The symbiont is going into neuroleptic shock.”

“I thought Trill symbiosis depended on isoboramine,” Juarez said.

“It does,” Bashir said, still incredulous over the magnitude of his error. “But the symbionts can’t tolerate it in large doses.”

“Is there an antidote?” Krissten asked.

Bashir gently took the creature from Juarez and cradled it in his arms. The symbiont convulsed in his hands as though about to burst. His mind raced to find an answer to Krissten’s question. Why was it becoming so hard to think?

“Yes,” he said after a moment’s hesitation. “Fortunately, there is a counteragent.”

Krissten grabbed another hypo and stood attentively, awaiting his orders. It was only after the moment began to stretch that Bashir realized that this time he wouldn’t need to drop a scalpel to endanger a patient’s life.

All it would take was a lapse of memory.

“Doctor?” Krissten was beginning to sound panicked.

His head began to pound, as though he were in the throes of severe raktajino withdrawal. He closed his eyes very tightly, willing the throbbing pain to pass.

“Give me a moment to concentrate,” he said, trying hard not to display his own rising alarm. The small, helpless bundle that contained the essence of the woman he loved continued to heave and shudder in his arms. He could feel intuitively that it was beginning to die.

“Doctor?” said Krissten, now clearly worried.

Bashir ignored her. He thought instead about the miracle to which Vaughn had attributed Nog’s new leg. And the cathedral-like alien structure that had clearly caused the miracle.

What better place than a cathedral to go looking for miracles?

And in his mind, he was no longer in the medical bay. No longer aboard the Defiant. No longer even in the Gamma Quadrant. His mind’s eye opened as he slipped into the stretched null-time of memory. Before him stood four great, russet-colored buttressed arches topped by a thirty-meter dome. The silvery structure gleamed under a clear desert sky, resplendent in the late-afternoon sun.

Shortly after his parents had taken him to Adigeon Prime for genetic resequencing, Bashir had discovered that he’d needed to find ways to cope with the torrential flood of information his agile mind had begun absorbing and retaining. At the age of eight, Bashir read a biography of Leonardo da Vinci, from which he had learned an appealing and useful mnemonic trick. Using the same care he had lavished on some of humanity’s greatest masterpieces, Leonardo had constructed a vast, detailed cathedral entirely within his formidable mind. Every vestibule, gallery, staircase, foyer, and chamber was carefully catalogued in the polymath artist’s memory, every sculpture and painting placed just so, every bookshelf, book, and page painstakingly arranged, indexed, and preserved for virtually instantaneous access.

All Leonardo had had to do to retrieve any specific fact he’d previously placed within his “memory cathedral” was to close his eyes, stride the great basilica’s wide corridors, and enter whichever carefully catalogued vault contained what he sought.

Young Julian Bashir had chosen a much simpler, though still impressive, design for his own mnemonic citadel—that of the Hagia Sophia, Istanbul’s great sixth-century cathedral. In all the years since, he’d never been tempted to move his personal treasury of memory into a larger, more complex structure, probably because of his father’s preference for the gaudier Baroque- and Rococo-period architectural styles of a millennium later.

In the self-contained universe of his own mind, Bashir bounded up the Hagia Sophia’s stone steps and ran through the arched doorway, through the vestibule, and into the wide aisle surrounding the central basilica. Of course, it had been years since he’d had to resort to using this mnemonic trick so directly; he’d long ago learned to place his memorization skills on a kind of intellectual auto-pilot, until his subconscious information retrieval had become virtually error-free, almost an autonomic function, like breathing.

He turned right and found the staircase he’d installed at the age of ten, the year he had first begun seriously organizing pharmacological information in his cathedral-of-the-mind. As he ascended, he noticed that the fifth step made an echoing squeak as he put his weight on it, just as he remembered. He recalled how he’d deliberately installed several such things throughout the building, as mnemonic self-tests. He smiled as he continued upward.

In a few moments he’d remember how to save Dax’s life.

A heavy oaken door stood before him at the top of the staircase. He pushed on it, but it was evidently locked from the inside.

He frowned. It should not have been locked.

He pounded on the door with his fists.

The door abruptly vanished, and he tumbled forward into a large, curving room that conformed to the Hagia Sophia’s exterior shape. The place was stacked to the ceiling with massive-looking wooden bookshelves. Waning sunlight streamed in through the gauzy drapes.

A dark-haired woman in a Starfleet uniform stepped into view from behind one of the nearer bookcases and approached him. She was human, and appeared to be in her mid-thirties. She smiled and extended a hand, helping him back to his feet.

It took him a moment or two to place her. “Dr. Lense?” Bumping into the woman who had narrowly beat him to the position of valedictorian of his Starfleet Medical graduating class, here in his own personal memory cathedral, both unnerved and perplexed him.

Elizabeth Lense smiled. “Don’t worry, Julian. It’s only natural that you’d wonder why I’m here.”

“So you’re telepathic. No wonder you got ahead of me back in medical school.”

She laughed, a pleasing, liquid sound. “I got ahead of you because even the best memories can hiccup once in a blue moon. Besides, I don’t need to read your mind, Doctor. I’m only a figment of your mind.”

He immediately felt foolish. “Of course. So why did my mind choose this moment to, ah, channel you?”

“Channel me? I’m not a ghost, either, Julian. I suppose you’re thinking of me because of an accidental confluence of tangentially related information.”

Of course. I remember. She’s serving aboard the U.S.S. da Vinci now. A ship named for the man who inspired me to build this place.

Her smile widened disconcertingly. “One thing’s for sure, Julian. You’ll never confuse a preganglionic fiber with a postganglionic nerve ever again.”

That had been the one exam question he had got wrong. That single error had cost him the privilege of giving his graduating class’s valedictory address. That all-too-rare failure of his prodigious recall skills would have remained etched into his memory forever, Leonardo or no Leonardo.

He had to force himself to stay focused on his current problem. Dax was dying. An antidote existed, but if the symbiont didn’t receive it within the next minute or two, then nine lifetimes would all be for naught.

Because I let myself get confused and distracted, Bashir raged at himself.

He shouldered his way into the room, brushing Lense aside, and made his way to a particular three-meter-high bookshelf cut from dark, tropical hardwood.

When he reached it, he was surprised to find the book spines in noticeable disarray. It looked as though many of the volumes had been taken out, rifled quickly, and then tossed haphazardly back onto the shelves. More than a few were out of order, misfiled slightly to the left or to the right of their correct locations. Many looked tatty and shopworn.

He started when he felt Lense’s hand on his shoulder. “Julian, please explain something to me,” she said. “Why did you bother to come all the way here just to look up the fact that ten cc’s of endomethalamine will counteract twenty cc’s of isoboramine inside a Trill symbiont’s vascular tract?”

Endomethalamine! He recognized the name of the correct counteragent as soon as he heard it. Of course!

“Doctor!” It was Krissten’s voice.

The memory cathedral vanished like so much smoke, and Bashir was once again conscious of nothing but the medical bay’s operating room, where Ezri lay, inert, barely breathing. Krissten and Juarez both stood staring at him, their faces portraits of worry.

Bashir felt the symbiont writhing and twitching in his hands.

“Doctor, are you all right?” Krissten said. The last time he’d heard her sound so fearful, the station had been under full-scale attack by the Jem’Hadar. “We need to get that counteragent into the symbiont.”

Bashir nodded, his full attention once again focused on the crisis at hand. “The counteragent is…” For a harrowing moment the knowledge faded, then just as quickly snapped back into place. “…endomethalamine. Please administer ten cc’s of endomethalamine, Krissten. Directly into the symbiont’s umbilical orifice.”

Bashir held the thrashing symbiont steady while Krissten performed the injection. A moment later, the symbiont grew quiescent. Krissten used her tricorder to check its vital signs. Then she took charge of the symbiont as Juarez helped her place it into the medical transport pod, securing the box’s seals and activating the biomonitors on its side. It took only a moment to ascertain that the symbiont was out of immediate danger.

No thanks to me.

Bashir suddenly recalled the question the faux Elizabeth Lense had asked him inside the memory cathedral. Why hadn’t he simply asked the computer for the information he needed to save Dax? That clearly would have been the expedient solution. Perhaps he had become too used to his facile memory. Or had placed too much blind faith in it.

But he also wondered if something more fundamental was happening to him. If his judgment was failing along with his memory.

An even more alarming thought followed: What if my entire intellect is disintegrating?

With that fearful notion came a profound fatigue, rolling irresistibly over him like the fogs of Argelius II. And with that fatigue came a sad, certain knowledge. He now knew beyond all doubt that he hadn’t escaped the bizarre, unpredictable influence of the alien artifact. He, too, had been aboard the Sagan when it had crossed the object’s transdimensional wake. Just like Nog. Just like Ezri.

Ezri.

He crossed to her biobed, where she lay like some moribund princess from a fairy tale. But he knew that no kiss would be potent enough to rouse her. He took her hand, placing it between both of his. It felt cool and moist. He checked her vital signs, which were weak but holding steady for the moment.

He bent down and gently gave her that fairy-tale kiss. “Good-bye, my love,” he whispered.

Her eyes fluttered open. She smiled at him.

“Ezri?”

Her voice was weak but steady. “Dax…is gone…”

He couldn’t believe it. So weak, so close to death, there was no way she could have regained consciousness. Bashir noticed that Krissten had run over to the other side of the biobed to check Ezri’s readings.

“Doctor, you have to look at this,” said Krissten, a stunned expression on her face.

Bashir glanced up at the biobed monitors. Every indicator, from neurological to metabolic to cardiovascular to pulmonary, was up significantly. Impossibly, Ezri was getting stronger. She was returning to normal, as though she’d never been joined to a symbiont in the first place.

“The symbiont,” Ezri said, her voice stronger, though her expression was desolate. “Julian, how is the symbiont?”

Bashir finally realized his mouth was hanging open. And his eyes were welling up with unshed tears. “The symbiont is fine,” he said, his voice cracking like an adolescent’s. “It’s safe in the artificial environment. But you…Ezri, I think we may find a way to get you through this after all.”

It’s impossible, he told himself. Joined Trill hosts simply didn’t recover after losing their symbionts.

She smiled up at him again, looking as tired as he felt. “This is the second time I’ve been at death’s door since we came to the Gamma Quadrant, Julian. I think I’ll wait until I’m strong enough to walk again before I actually step through it.” Then she drifted off to sleep once more, her smile lingering.

Perhaps I found Vaughn’s miracle after all, he thought, finally daring to believe it. After all, was Ezri’s survival of the loss of her symbiont any more miraculous than the regeneration of Nog’s leg? Or were such things really miracles? He found himself wondering abstractedly whether the alien artifact might really be a super-advanced medical facility, the product of brilliant, unfathomable alien minds.

Abruptly, his fatigue overtook him. He collapsed to the deck beside Ezri’s biobed, visions of the ancient spacebar artifact vying with Istanbul’s Hagia Sophia for the attention of his unconscious mind’s eye.