The journey back to the buried Ancient buildings was made in solemn silence. Jack left Mitchell outside to guard while he and Teal'c made their way inside. Daniel and Sam were the first people he saw; they sat together at the same station the archaeologist had been using when Jack had arrived with Sam earlier.

Sam immediately looked up at their entry. She got to her feet. 'Is something wrong, sir?' She asked worried at his serious expression.

Daniel frowned and he scanned Jack and Teal'c's faces concerned. 'What's going on guys?'

'There've been a few developments.' Jack said taking off his cap and crumpling it in one hand. 'Firstly, Ba'al is on his way here.'

Daniel blinked. 'You're kidding.'

'He is not on this occasion, Daniel Jackson.' Teal'c said clasping his hands behind his back.

'He thinks his ploy with the weapon worked and we're at each other's throats,' surmised Daniel folding his arms.

'No,' Jack contradicted him, 'Byn'c already told him he'd failed with that plan.'

'Byn'c?' Daniel's eyebrows shot up. 'He's a spy?'

Teal'c nodded grimly. 'He was, Daniel Jackson.'

Daniel pushed his glasses up his nose as he assimilated the tense Teal'c had used. 'I guess that explains why he was so keen to kill Cral'k. He probably thought Cral'k would reveal everything about him too.'

'You may be correct.' Teal'c admitted.

'It doesn't make sense.' Sam said confused. 'If Ba'al knows the alliance is holding, why is he attacking?'

'Oh he has a new play-mate.' Jack replied gesturing with his baseball cap.

'Who?' Daniel asked. 'I thought all the major Goa'ulds were dead.'

Jack sighed knowing he couldn't avoid telling them any longer. 'Byn'c told us it was a human form Replicator before he was killed.'

Sam paled and Daniel rocked back as though he'd been hit.

'Now, it's possible it isn't the one that looks like you.' Jack began, his eyes on Sam's tense face.

'Sir,' Sam cut in, 'she was the only human form Replicator we were aware existed at the time we used the Ancient weapon to defeat the Replicators.'

'Then how did she survive?' Jack demanded.

'I don't know.' Sam retorted not caring her tone was bordering on insubordination.

'I might.' Daniel admitted reluctantly. 'She was in my head trying to get to all the knowledge I had in my subconscious about being ascended.' He sighed. 'It's possible that she was able to save herself by ascending when the disruptor wave from the weapon hit.'

'It's possible.' Sam said thoughtfully. 'She would have had some warning from the initial destruction of the first few Replicators. Maybe it wasn't enough time to use the cipher like they did with the version of the weapons we and the Asgard were able to build but it might have been enough time for her to ascend.'

'Only the Others must have sent her back like me.' Daniel murmured. He shook his head. 'This is my fault.'

'No it's my fault.' Sam argued. 'She wouldn't even exist if it wasn't for me.'

'This is no-one's fault,' Jack said forcefully, 'and I need you both focused on finding a solution to this not blaming yourselves. Is that clear?'

'Yes, sir.' Sam said her tone overly formal in response to the sharp reprimand in the General's.

'It's a shame you just blew up the Ancient weapon.' Daniel commented with a sigh. 'We could have used it to destroy her.'

Teal'c shifted almost as though he was embarrassed. 'We did not blow the weapon up.'

'You didn't?' Daniel checked confused. 'We heard the explosion from here.'

'The bomb did not impact the weapon at all.' Teal'c informed them.

'So we can still use it.' Daniel said excitedly.

'No,' Sam shook her head, 'not without knowing the frequency the weapon would need to be set to. No doubt she's altered the frequency spectrum of the Replicators to be immune to it by now.'

'Well, what about our counter-measure?' Daniel protested gesturing at her. 'Can't we get one to all our allies?'

'We only have the one I built and it will take time to build more.' Sam pointed out.

'The fact is, Daniel, we just can't take the risk of the weapon falling into Ba'al's hands or the Replicator's.' Jack said. 'We have to destroy it.'

'How will we destroy the Replicator?' Daniel asked bemused.

'We still have the disruptor technology.' Sam answered before Jack could respond. 'All we need is the right frequency setting.'

'Have you discovered a way to destroy the weapon in the information from the Ancient systems?' Teal'c asked.

Daniel shook his head. 'We haven't even found any information on the weapon. Since we thought you were blowing it up I've been concentrating on finding out why the control chair only responds to Sam…'

'And I've been looking at the power source inter-dimensional technology with the rest of the science team.' Sam completed.

'So that's a no?' Jack summarised. He sighed and his brown eyes met Sam's apologetically. 'Carter, we need you to use the chair and discover a way to get rid of that weapon.'

Sam straightened. 'Yes, sir.'

'I thought you didn't want us to use the chair.' Daniel said.

'If you have another idea, Daniel, I'm all ears otherwise we're out of time and out of options. We'll have to take the risk of Carter destroying the galaxy.' Jack stared at the archaeologist who stepped back and waved them all down the stairs.

The rest of the science team had already stopped working during the discussion and they moved out of the way as the SG1 team made their way to the chair.

'You can do this, Carter.' Jack said reassuringly.

'Yes, sir.' Sam lowered herself into the chair.

'Focus on switching off the weapon.' Daniel coached as the chair swivelled and dipped.

Sam tried to focus her mind and had a sudden wave of sympathy for all the previous times she had encouraged the General to do the same when faced with Ancient technology; it certainly wasn't as easy as it looked. A schematic suddenly projected into the air in front of the chair.

'Daniel?' Jack asked.

The archaeologist squinted up at the tightly written information. 'OK, we have a problem.'

'I don't want to hear that.' Jack said to him.

'According to this the weapon cannot be destroyed exactly. They protected it with an impenetrable invisible force-shield that repelled everything. That's probably why your bomb didn't work. The force-shield is integrated into the weapon…' Daniel frowned. 'There's a lot of technical detail here…something about the weapon pulling its energy from sub-space…' he sighed and wrinkled his nose, 'if I'm reading this right the only way to switch it off is to interrupt the energy flow between the weapon and its power source in sub-space.'

'How do we do that?' Jack asked.

'They don't say.' Daniel said.

The schematic changed suddenly to the inter-dimension technology of the power source.

'Sam?' Daniel asked worriedly.

'Sorry,' Sam said, 'I was just thinking…'

'I know it's practically an impossibility for you but maybe you shouldn't do that while you're in the chair, Carter.' Jack said nervously.

'No, it's OK.' Daniel said waving his hands at the projection, 'I see where she's going with this.'

'You do?' Jack asked.

'Yes.'

Jack sighed impatiently. 'You want to clue the rest of us in here, Daniel?'

'Uh?' Daniel looked over at his friend and saw Jack's irritation at not knowing what was going on. 'Well,' he began, 'if we can't destroy it…'

'We can try sending it somewhere else.' Sam completed.

'Send it somewhere else?' Jack repeated.

'I think we could send it to a different dimension, sir.' Sam said.

'Oh.' Jack's eyebrows shot up. He had thought he was incapable of being surprised anymore but he'd been wrong.

'But you can't do that.' Bill said stepping forward. 'I mean we can barely identify the fact that the technology is accessing another dimension let alone use it.'

'But if Sam focuses on what she wants to do, the chair should help extrapolate the 'how' from what it knows from the system.'

'That's a big if.' Bill said with a dismissive snort.

'Is this safe, Colonel Carter?' Teal'c asked. 'Cannot the weapon still be used if it is in a different dimension?'

'Good question, T.' Jack said.

'I guess it could be used,' Sam admitted, 'but it wouldn't affect anything in this dimension and it's possible that shifting it into a different dimension would be enough to interrupt the power source and shut it down.' Her eager blue eyes returned to the General's. 'I know it sounds a bit whacky, sir.'

'Well that's never stopped us before.' Jack quipped. He sobered. 'You really think you can do this?' He checked.

'Yes, sir,' Sam confirmed, 'but we're going to have to do this now. I think if we're going to be successful, it's going to take all the remaining power. We won't have the ability to continue the study.' Or find out what was happening to her, she thought worriedly.

Jack sighed and rubbed a hand through his grey hair. His brown eyes caught on hers. She knew the same thought had occurred to him and knew before he said the words what his decision would be; he was too good a military officer for it to be anything else – if he wasn't she would never have fallen in love with him. 'Do it.' He said.

'Wait!' Daniel held up a finger. 'Just wait.' He told Sam. 'Jack, could I have a word?' He didn't wait for an answer; he was already walking out. He stopped in the ruined first chamber and switched on a flashlight.

'What's going on, Daniel?' Jack asked impatiently. 'We don't have time for this.' He was certain he was about to get a lecture about the valuable information they were about to throw away by going ahead.

'What about Sam?' Daniel said bluntly.

'What about Sam?' Jack asked taken aback.

'If we use the power up we can't access the information in the Ancient systems any longer. We may lose our opportunity to understand what's happening to her.'

'You don't think I know that, Daniel?' Jack returned swiftly.

In the darkness, Daniel missed the flicker of anxiety across Jack's face. 'Jack, she's building counter-measures for advanced alien technology in the space of a day; she can suddenly operate a chair that controls that technology but nobody else can.' He gestured back at the chamber they had just left. 'Does this in anyway sound familiar?'

'It does,' Jack admitted, 'which is why I called the Asgard when Carolyn couldn't find anything.'

'So you have to…' Daniel's brain caught up with Jack's words. 'You called the Asgard?'

Jack nodded. It was the only thing that was helping him accept his decision might prevent them from understanding what was happening to Sam.

'Oh well.' Daniel stuttered and fidgeted with his glasses to cover his confusion.

'We done here?' Jack asked mildly.

'Yeah.' Daniel nodded and peered through the torch-light at the other man as he took a step back to the others. He had underestimated his friend, he realised. 'Jack.'

Jack turned back to him.

'She'll be OK.' Daniel said comfortingly.

Jack nodded jerkily. Six days and counting, he thought. He sighed. 'Come on. We've got to send an Ancient weapon to another dimension.'

'You'd rather blow it up wouldn't you?'

'Yep.' Jack agreed as they made their way back down to the chair.

Sam looked at the pair questioningly.

'OK, let's try this.' Jack said.

'Yes, sir.' Sam glanced at the interested scientists and cleared her throat. 'Perhaps we ought to move everyone out, sir, as a precaution. I don't know what will happen in here when the power gives out.'

Jack nodded and waved at the scientists. 'Everybody out.'

There was another wait while everything was packed up and the scientists ushered outside to Mitchell's protection. Teal'c and Daniel returned to the control chair.

Sam sighed at the sight of the three of them standing beside her. 'You should all leave too.'

'Teal'c and Daniel, outside.' Jack ordered. He had no intention of leaving her alone.

Teal'c raised an eyebrow and simply adjusted his stance. His body language was clear; he wasn't moving. Jack sighed and his gaze slid to Daniel who stared back at him stubbornly.

'Right.' Jack said softly.

'Guys…' Sam began.

'We're staying, Carter.' Jack said firmly.

Sam nodded and swallowed around the lump in her throat. She closed her eyes on the image of her three team-mates. Her brow creased in concentration as she thought of the weapon; thought of the Ancient inter-dimensional technology and thought of moving the weapon into another dimension.

The ground began to shake.

Green static flowed over the consoles.

The Ancient weapon trembled as the green static travelled up from the ground and covered the control table, covered the outside of the temple where it resided. The Jaffa guarding it staggered away from it in shock and fear.

Sam's fingers clenched in the hand controls of the chair and a sharp pain shot through her head. She ignored it and focused on the weapon, on achieving her goal.

The air crackled with electricity.

A shot of green power shot out from a console; Jack tackled Daniel and the two men hit the ground as it careened through the space where they had just been standing. Teal'c crouched as more bolts crackled through the air.

The sky thundered as the temple was covered by a green net of power sending the nearby Jaffa scurrying for safety.

Sam used the last of her strength. Outside, the Ancient weapon disappeared into another dimension with a sudden crack of thunder leaving a wide open space where the temple had once stood.

Inside the Ancient chamber, Jack lurched to his feet as the room shook ominously. He dodged a falling piece of roof and threw himself across an unconscious Sam. An instant later he felt Daniel joining him and then Teal'c, all of them protecting her, as the consoles around them exploded. Suddenly, the earth stilled and the chamber was plunged into darkness.