Like a pneumatic drill shattering a pane of glass, Captain Benjamin Sisko came awake to the sound of the station's intercom beeping loudly in his quarters. "Dax to Sisko," was the phrase that followed it. He ran his hands over his bald skull and sighed heavily. "Go ahead, old man." It was morning, technically, but way too early for Sisko. If this was a minor glitch in the complaining child of Deep Space Nine's computer core, he vowed that heads would roll. But it was Jadzia Dax, his friend and close companion for almost seven years; she wouldn't be waking him up for anything insignificant.

"Sensors are detecting a temporal fluctuation in the Denorios Belt. Its severity has increased by the hour. Should we investigate further?"

Sisko sat up and started the long journey to getting out of bed. He chastised himself for this every morning: there was a war going on between the Federation and the Dominion. He had to be ready and alert. But as far as he was aware, Dominion sciences didn't stretch to include quantum mechanics, so he dismissed an attack for the moment. "Have you launched a probe?"

"Already done. It's sending back some strange readings, but the data stream isn't cohesive; I'd need to be closer to get uninterrupted scans through. Are the runabouts still down for their maintenance cycle?"

He could hear the question behind the question in her voice already. "Yes," he murmured thoughtfully, then pushed himself to a standing position and started rummaging for his uniform. "Start preparing the Defiant, then. Launch in ten minutes."

A laugh echoed down the comm link. "I'm way ahead of you: the Defiant's already in pre-flight checks. I'll see you in ten." She closed the channel, and Sisko felt a grin spread across his face as he pulled his Starfleet uniform on. Technically, Dax had the authorisation to fire up their resident starship, since she was the acting commander at the time, but if he wanted, Sisko could have filed it as a breach of protocol. Nonetheless, she was right. He suddenly felt very predictable while he walked to the replicator and ordered a quick breakfast. Now was the time to have his morning cup of coffee, seeing as the Defiant's bridge replicator could only synthesise hot or cold water. He ate as much as he could in the remaining few minutes, then placed the remains back in the slot and tapped the reclamation button.

"Sisko to Ops. Lock onto my signal and beam me to the Defiant's bridge."

"Aye, sir," came the reply, and Sisko faded out in a column of bright golden light.

Lieutenant Commander Jadzia Dax, Trill science officer extraordinaire, took a last look at the readouts she had obtained from the probe's data stream. It was unlike anything she had ever seen…a substantial comment, seeing as the Dax symbiont had been alive for six generations. A frown creased her normally smiling lips as the information scrolled across the screen in front of her. Even though she didn't know exactly what the anomaly was or did, she already had a bad feeling about it.

The humming sound of the station's Cardassian transporter shook her clear of her premonitions, and Captain Sisko materialised behind her. She could tell it was him without looking around, judging by instinct and the heavy noise as he fell into the Defiant's command chair. "Dax," he ordered. "Get docking clearance from Ops, then plot a course for the anomaly. Prepare for departure, one-half impulse."

"Aye, sir," she replied, and suddenly she was professional and business-like once more. Beneath her fingertips, the compact vessel detached from its berth and swung around towards open space. Dax slowly got them clear of the station, then kicked them into warp five on a course for the Denorios Belt.

Colonel Kira, seated at Tactical II, swung around in her chair. "Captain, we have a message from O'Brien. He says it's urgent," she said.

Sisko nodded at her. Miles O'Brien was temporarily in charge of Deep Space Nine whilst the rest of the senior crew were investigating the temporal anomaly. Kira tapped a button, and the faintly Irish brogue of the Chief of Operations officer filled the small bridge. "Captain, we've just lost probe telemetry."

"Lost it? You mean the probe was destroyed?" Sisko inquired.

"I'm not sure — one minute, we had a signal, and the next…boom! It was gone. Our scans aren't detecting the probe either. Orders?"

Sisko looked from Dax to Kira, hoping for a suggestion. In the end, Dax shrugged and said, "Chief, we're almost there. Transfer the last readings to us, and we'll take it from here."

"Acknowledged. DS-Nine out."

The captain eased a crick out of his neck. "Any further readings, Dax?" he asked slowly. She knew that tone of voice, from the days when she used to be a he, namely Curzon Dax. It was the voice that tried to sound nonchalant and in control, but to an experienced listener, betrayed a depth of worry and anxiety that was almost unimaginable in a man like Sisko. She shook her head in the negative and turned back to the helm, watching the stars streak by on the viewscreen. "Once we're there, I can use our own sensors to adequately scan the anomaly. Hopefully, I can get a more conclusive reading," she replied, trying to soothe his unease. She got the feeling that it wasn't working too well, so she settled back into her chair and waited the last few minutes until she decelerated back into normal space.

That was, of course, assuming that one could call the Denorios Belt normal. It was a combination of an unusual plasma field and an asteroid belt all rolled into one, and it had more than its fair share of unusual scientific properties. The Federation's science division had long been fascinated by the Belt, and Dax's in-depth studies into it had become a considerable merit in her career. She felt that if a bizarre phenomenon was going to take place within the vicinity of the station, it would be somewhere near the Denorios Belt. Its inky-blue plasma clouds now filled the viewscreen, like a mist left by a giant octopus.

"Scanning for temporal emissions now," she reported.

Worf, who had remained quiet at Tactical I, swivelled and stared into the screen. "Captain, the Enterprise once used an inverse tachyon pulse to scan an anti-time anomaly. Could we possibly employ a similar method here?"

"Maybe," came Dax's response. "But as far as we can tell, this irregularity doesn't conform to anti-time parameters. It may give us something useful if we pipe it through the temporal spectrometer, though."

"Do it," murmured Sisko.

There was a short pause, then a bleeping noise from the helm. "I've found it," said Jadzia excitedly. "Co-ordinates one-four-seven mark four-three. Size…eight kilometres across and expanding. One moment…no sign of the probe."

She could almost hear Sisko frown. "Any debris or computer buoys?" he asked.

"Not that I can find. It looks like it just vanished." She winced a little when she caught a glower from her commanding officer. "Of course, the chroniton emissions could be masking the probe's engine signature. Give me a few minutes, and I should be able to locate something."

"Captain," Worf murmured again. "According to my preliminary readings, the anomaly is expanding exponentially. We do not have time to search for one missing probe."

"I have to agree with you, Commander," Sisko replied, one hand absent-mindedly stroking his beard. "Old man, I want you to focus on determining the composition of the anomaly. How long will it take you to get this tachyon scan operational?"

She shrugged a little. "About twenty minutes, if Engineering can spare two crewmen."

Half an hour later, the results of Dax's first tachyon sweep of the anomaly scrolled onto the viewscreen. Most of the senior staff did not pretend to understand some of the more complicated scientific terminology, but Jadzia interpreted where she could. "What we're looking at is some kind of…fountain of temporal energy, comprised mainly of chronitons. There's a lot of strange particle emanations in there that I can't pin down: it looks like a new kind of energy to me."

"Fountain?" Kira asked quizzically.

The Trill frowned at her inability to locate a more correct term. "I don't know what else to call it. But whatever it is, it's growing at an oscillating rate. Estimations show that it'll be within five hundred kilometres of the station within the next two weeks sometime. We don't know what it's going to do to DS-Nine itself."

"What about a static warp shell?" said Worf. "It could curb the instability and possibly collapse the rift."

She shook her head. "As I said earlier, this isn't an anti-time phenomenon. But there has only been one use of the static warp shell to perform such a task. Who knows? Maybe that is the way to get rid of it." She sighed helplessly. "As it is, we don't know. All we can do is conduct more scans, maybe launch another probe."

A high-pitched chirp from Worf's console turned his head and sent his muscular fingers flying across the controls. "Captain!" he growled. "I'm picking up a Starfleet transponder signal — it's the Rubicon!"

"The Rubicon?" Kira echoed. "It's in for maintenance today. I'm sure of it."

"Confirmed," said Dax from the helm. Sisko merely nodded quietly. Jadzia added, "But it's on a different subspace band to the Rubicon's usual frequency. That's odd…I'm getting some strange energy fluctuations."