Disclaimer: Anything and anyone you recognize does not belong to me but their respective owners. No copyright infringement is intended; I only borrowed the characters to satisfy my muse's need to mix my favorite sci-fi TV series with one of my favorite sci-fi movies. I promise to give them all back after finishing the story.

Author Note: I just noticed that nearly four years have passed since I wrote the opening scene. My, how time flies… The good thing is that this story is already completely written so you won't be bothered with my erratic muse and long periods of silence in-between sporadic updates. I will probably publish a chapter once a week. I hope you like where I took it and am looking forward to reading your opinions (aka reviews).

For all my readers waiting for an update on "Transformers Prime: Stardust": I'm working on it. I haven't given up on the story. My muse has just been otherwise occupied. But I am expecting progress in the near future, now that "The Comet Enigma" has been concluded.

Enough waffling. Enjoy!

– prologue –

Nightfire

It was a clear night, perfect for stargazing.

Major General Jack O'Neill sat on the roof of his house, the telescope turned skyward. Above him, there glittered millions of stars in the seemingly endless void that formed space. Suns, he corrected himself mentally, somewhat amused. Stars are suns. He briefly wondered how many he had seen from a much closer perspective during his travels all across the Milky Way. He would never know, unless he asked Carter about it – which he most likely wouldn't unless he wanted to be subjected to an hours-long lecture on astrophysics.

Somewhere in the neighborhood, a dog started barking angrily, probably to scare a stray cat. Jack found himself listening whether he could hear the feline. And sure enough, a moment later, there was hissing to be heard. Quickly afterward, silence settled over the area again.

It was disturbed once more when the nearby church bell started chiming, indicating that it was only another hour until midnight. Jack wasn't tired yet though. He knew that the later the hour, the better the chance to see something spectacular. Had he known exactly how spectacular – in the negative sense – this night was going to turn out, he might have considered calling it a day and going to bed. But Jack stayed outside to continue his stargazing.

Just moments after the bell had silenced again and when Jack had momentarily turned his gaze heavenward without the telescope, he noticed a group of four oddly flickering stars on the higher western horizon. He frowned and quickly turned his telescope in this new direction. Peering through, he discovered that it was not stars he was seeing, but rather comets. "How odd," he mumbled to himself. He would have thought that comets were loners and did not travel in groups; at least, he had never before heard of a group of comets traversing the earthen sky. But there was a first for everything it seemed.

While he continued watching the comets over the next minutes, he noticed that they grew in size. Rapidly. And then Jack realized the comets were heading directly toward Earth.

Instead of him feeling surprised at this discovery or even shocked, reflexes acquired thanks to many years in active field service kicked in and took over his next actions. Jack jumped up from his seat and made for the closest telephone available: his cell. His fingers flew over the keys, speed-dialing, before holding the phone to his ears. All the while Jack kept his eyes fixed on the comets whose tails grew even longer when they started entering the atmosphere. They never slowed down while tearing through the sky.

…

Lieutenant Colonel Samantha Carter was working on her latest project which kept nagging at her, the design of a laser weapon. During a series of simulations earlier that day, she had encountered a problem in the energy output resulting in failure of all scenarios provided by the computer. The analysis of the data collected during the test had uncovered a miscalculation. Determined to get the laser weapon to work earlier than later, Sam had gone over the calculations again, trying to erase the error to make the energy output work. The afternoon had thus run by without her noticing it. Only when General O'Neill had suddenly stood in her lab's door, asking when she was leaving for home, did she glance up at a clock.

But since she had been close to getting to the bottom of the test failure of this morning, she had opted to stay. So when the telephone rang and startled her out of her calculations, she was hungry, tired and slightly pissed off at having been interrupted – not necessarily in that order.

"Carter," she therefore barked into the phone just after the second ring, not bothering to check for the ID.

The caller spared the greeting. "Is there a scientific explanation to comets nowadays travelling in groups?" a man asked. She would recognize that voice anywhere; it was General O'Neill.

Sam felt slightly guilty for her impolite response to his call, but it was the less important of her thoughts right now. Truth was, the question was confusing her. She was used to General O'Neill being somewhat random at times, but this question beat everything so far. "No, sir," she eventually answered, slowly. She switched to another computer and quickly brought up every data she had about comets. What she read confirmed her first thoughts. "Comets travel alone," she told her superior officer before adding an inquiry. "Why do you ask?"

"Well…" Through the phone, she could hear him sit down. "I'm right now tracking a group of four comets from my private observatory," he told her. "They first appeared on the higher western sky, made contact with the atmosphere and by now have descended majorly. They're nearly gone behind the Rocky Mountains."

His report surprised her. "Four comets? That is impossible…" She trailed off while doing a quick research. "I just checked the databank of the IAU*; there are no comets announced for quite a while, sir, let alone a group of four."

"Explain that to the ones in the atmosphere," the general muttered. There was a moment's pause, then, "And now they just vanished behind the mountains."

"Noted." Sam typed furiously on her keyboard. If a comet hit Earth… As soon as she found what she was looking for, the upcoming panic turned to amusement. Grinning, she announced, "NORAD's satellites have picked up your 'comets', sir. For the record, those aren't comets but meteorites."

"Oh," came from the other end.

Sam smiled and continued, "There seems to be nothing in the news. Yet. I suppose it's just too late to still be awake."

"Then why are you still up?" came the reply.

"I could ask you the same, sir," she said before remembering who she was talking to. That she felt this at ease around a superior officer proved how long she had been working with General O'Neill. "I'm still working on the calculations."

"Ah." There was a pause, then the general asked, "Didn't I order you to go home?"

Smiling to herself while typing on the keyboard again, she replied, "Yes, sir."

"So you're not following an order, Carter."

"No, sir."

"Carter, do you know wh—"

"Yes, sir, I know." The banter was light and Sam knew she wouldn't get in trouble with General O'Neill for not having followed his order to go home, but she had to focus on the reason why he called in the first place – and remind him along the way. "Sir, according to the satellite feed, the meteorites have entered the atmosphere over central Nebraska and are heading straight for California." She typed again. "The computer calculated the impact to be near the town of… Tranquility." She hesitated for a moment before musing aloud, "If you ask me –"

"I called you so I am asking you."

Sam smiled at his joke. "Since you ask me, I say that behavior's strange. Meteor showers happen quite regularly, but usually, there is forewarning. There has been no information about these four at all. . My first instinct says it's not natural."

Over the phone Sam heard the general groan and utter a brief "Crap." She could easily imagine how he had hoped that for once in his life he would get the chance to stargaze without any weird interruptions. "All right, call the necessary institutions. I want a cleared team on site a.s.a.p. to check these meteorites out."

"Yes, sir." She hesitated, then added, "It's a drive of about twenty hours to Tranquility, sir."

"I want a briefing at 07:00 hours so you better be there before 07:00 hours."

"Of course, sir." Which meant they had to take a plane. She hoped someone of flight control was still awake at this late hour.

"Oh, and Carter?" the general quickly added before Sam could hang up. "Try to make sure it's not alien in nature."

She grinned, deeply amused when answering, "I'll keep that in mind, sir," before ending the call to dial up Peterson.

—

* IAU – International Astronomical Union