A/N: Fanficaddict, Dragonfairymaiden, LTwill, Dr.Dredd, Jules47, angw, Robyn, MacCartney, Rowana Farrin, Crockett, Drufan, and puddles1311 - thank you all so much for the reviews so far.

FYI This fic has been completed and comprises 12 chapters (not counting the Teaser). Assuming I can get access to a computer, I will be updating twice a week from now on.

Chapter 1

30 hours earlier…

The decorous chiming of Atlantis' alarm system as always drew everyone's attention from their tasks. "Incoming wormhole!" came the shouted warning as lights flickered around the ring of the Stargate, settling on various of the symbols marked on it.

Doctor Elizabeth Weir turned sharply, surprised at Grodin's call. A brief check of her watch confirmed what she already knew: they currently had three teams on other worlds for various reasons, and none were due back for several hours yet. Even as she looked up the familiar liquid whoosh of an establishing wormhole settled to leave a gently rippling blue surface. "Activate the Shield," she ordered tersely, moving over to Grodin's desk as the latter swiftly pressed the appropriate symbol. Below them a barrier flared into life across the Stargate's surface while a squad of heavily armed marines took up defensive positions around the Gate. Through long habit she cast her eye around the Control Room, memorising the personnel on duty and noted the sudden presence of Doctor Rodney McKay taking the seat at a nearby computer to check incoming signals through the Gate. "Got anything?" she asked.

"IDC being received now. It's Frankel's team," he announced without elaboration.

"Lower the Shield," she said with forced calm. During her brief tenure at the SGC she had quickly learned that the early return of an off-world team usually meant the worst. Half dreading the reply she might receive, she spoke into the headset she wore. "Lieutenant Frankel, what's your status?"

"We've found something in the wreckage of the ship that was sending the distress signal picked up by the MALP," he began, the excitement in his tone clear even through the static in the transmission. "We can't be sure: I for one have never seen anything like it, but Doctor Zelenka checked it over and he thinks it might be some sort of power source. He's managed to disconnect it from the wreckage and it appears to have gone inactive. Zelenka wants to bring it back to work on."

"What is it?" cut in McKay's suddenly interested voice.

Weir hid a grin. Since spraining his ankle after a high speed, nick-of-time dive through the Stargate escaping some less than friendly locals on a planet visited by Sheppard's team a few days earlier, McKay had been hobbling around on crutches and generally feeling miserable. It had only got worse when earlier in the day Sheppard, Ford and Teyla had been obliged to leave him back on Atlantis while they went offworld on a milk run to pick up some much needed supplies. In the hours since they had left, McKay had moped around the Control Room, desultorily checking systems, fiddling with the settings on some of the computers that were hooked up to their Atlantean counterparts and generally annoying the hell out of the people stationed there.

Had anyone accused him of being worried for his team-mates, he would have laughed it off, tossed in a sarcastic comeback for good measure, and returned to his aimless tinkering while he waited for their safe return.

"Doctor McKay!" exclaimed Zelenka's surprised voice, "I thought you were off duty? Ah, never mind. I think this is a very interesting thing we have found," he continued, his accent thickening in his excitement. "I am hoping to tell you more later, but initial tests show it has potential power output much greater than our Naquada generators, though unfortunately nothing like a ZPM. Perhaps with more testing I think it might be possible that we can adapt it to use with our equipment."

"Any idea of how it works?" asked McKay, an eager expression on his face, the misery of the previous hours swept aside as his mind latched on to a tantalising new puzzle.

"Hold it, you two," interrupted Weir before the two scientists could get too involved in their debate. As fascinating, not to mention useful, as it all sounded, she had a more pressing concern. "Lieutenant Frankel, Doctor Zelenka, do you think it's safe to bring this device back to Atlantis?"

There was a moment's pause before Frankel replied, "Ma'am, I can't see anything that looks obviously like a threat or a security device, but like I said, this thing is way beyond anything I've seen before, and that includes what I've seen of the stuff the Goa'uld use."

"I agree, Doctor Weir," added Zelenka, "we cannot be sure without much more investigation, and for such investigation we must bring it back to Atlantis. To bring such an object back is a risk, yes, but if the readings I've been getting from it and the preliminary calculations I've made are correct, I think there is the potential that it may have sufficient power to at least partially activate the City's main defensive shield."

Weir glanced over to McKay. "Sounds like it might be useful," he grinned, the discomfort from a sprained ankle temporarily forgotten in his impatience to start checking over some bit of unknown technology.

She nodded slowly. "Alright, lieutenant, bring it back. Rodney, put a team together to start working on it, but be careful! If it has the kind of power output Zelenka says…."

"Don't worry, Elizabeth," McKay brushing aside her concerns with characteristically blithe confidence, "I have no intention whatsoever of blowing myself up."

A few minutes later Lieutenant Frankel's team emerged from the gate, balancing between them something the size of a large steamer chest on the back of the cart.

o0o

"Ah ha!" crowed McKay triumphantly as a low, almost subsonic, thrum of power began reverberating through the laboratory. At a nearby workstation Zelenka, who was using one of the laptops the expedition had brought through with them to monitor the Canadian's progress, looked up with a matching grin. Others of the scientific team were stationed around the lab, making their own observations, glancing occasionally at McKay as the readouts they were tracking hiccupped or wavered through nothing more than, each hoped, his ceaseless fiddling with the device's settings.

"How's that?" asked McKay as he made a few more tiny adjustments.

"No better than the last two dozen times. As before, I am reading considerable potential here, much as I observed on the planet, and indeed, much as we have seen while we have been working on it so far," the Czech replied after watching the computer readouts for a couple of seconds, "but still we are not managing to create measurable power output."

McKay frowned in annoyance, sighed, and experimentally flicked one of the many switches on the device to and fro a couple of times. Getting no reaction from the monitoring scientists, he walked over to peer over Zelenka's shoulder at the readouts, favouring his ankle as he did. With scant regard for the Czech's presence, he reached past him for the keyboard and started toggling through the records of displays and readouts they had amassed over the previous hours of work, pausing here and there to double check settings.

"Doctor, so far it's behaved differently from any other power source we've seen," ventured another of the team. "Perhaps it's our set up that's at fault. We've been working on the assumption that it's functioning broadly parallels other power sources we're familiar with. If that initial assumption's incorrect, maybe we've just got the connections wrong?"

"Well, naturally," groused McKay, "why don't we all take everything apart and put it all back together again in a different order." Acid sarcasm leeched into his voice. "Here I am surrounded by people who are alleged to be amongst the top scientific minds in their fields and the best idea anyone's come up with so far boils down to 'let's switch a few wires around and see if it works then'. Why on earth should we want to use any different technique to connect up an alien power generator than mimic what most idiots do when they're trying to get their DVD player to work?"

An embarrassed silence settled over the laboratory. McKay looked at Zelenka who shrugged and offered an apologetic half smile. "It couldn't hurt, could it, Rodney?"

McKay sighed wearily, nodded in reluctant agreement and curtly yanked out a handful of the wires he had spent the previous hours connecting to the device.

Immediately they came loose, the formerly rhythmic, almost comforting low thrumming of power hiccupped and stuttered. Around the laboratory the smoothly curved wave patterns displayed on monitors leapt sharply, their arcs shattering into hard edged fractals. Laptops started chirruping alerts to users who were already frantically trying to work out what had happened. McKay looked around the lab, taking in the readouts. "Oh, definitely not good…" he muttered.

Above them, all but ignored amidst the growing hubbub, the familiar chiming of the City's alarm began to sound. Moments later a gently modulated, sepulchral voice started to intone something in a language some recognised but none understood. For a couple of seconds Zelenka tilted his head, listening but not understanding. Before returning his full attention to his work, he noted absently how the words had sounded oddly reminiscent of Mass.

Then Mass or anything else was suddenly the last thing on his mind as one after another, the laboratory's laptops and monitors crackled, smoked and exploded, filling the air with the acrid stink of burning plastic. The monitor on his own machine flared white, and when he saw thin plumes of smoke rising from the keyboard he stumbled backwards, overbalanced and fell.

"Do prdele!" the Czech swore from his sprawled position on the floor.

o0o