Mitchell got back to his feet. He had ordered everyone up against the mountain wall and to keep low when the ground had begun to shake. He brushed the red dust of his green BDU pants and he peered into the entranceway back to the chamber. He clicked on his P90 light and shone it into the darkness. His heart sank at the closed-in tunnel; there was rubble blocking the way half-way down and clouds of dust still rising from the floor.

'Damn.' He muttered. He reached for his radio. 'Colonel Carter. Come in.'

Nothing.

'Sam, please respond.'

There was an eerie silence. The scientists hovered just behind him in muted anticipation.

'General O'Neill. Please come in.' Mitchell tried again.

More silence.

He took a deep breath. 'Teal'c. Do you read me buddy?'

'I read you, Colonel Mitchell.'

'Yes!' Mitchell punched the air before he radioed back, his voice vibrating with relief. 'You guys OK?'

It was the General who responded. 'Carter's got a hell of a headache but we're all OK.'

'That's good to hear, sir.' Mitchell radioed back. 'We have a small problem, General. The passageway from the chambers to the outside has suffered a cave in. We're going to have to dig you out.'

'Understood.' Jack radioed back. 'Keep us apprised of progress.'

'Yes, sir.' Mitchell said his mind already turning to the task of rescuing his team-mates. 'Don't go anywhere.'

'Funny, Mitchell.' Jack clicked off his radio and settled back against the side of the chair where he had ended up after they had untangled themselves and Sam had come to.

'We're trapped?' Daniel repeated next to him.

'Looks like it.' Jack said. 'Mitchell will get us out.'

'I'm confident.' Sam said thinly rubbing her forehead. She was curled up in the chair nursing her headache.

'Me too.' Daniel agreed cheerfully. They had been in worse situations.

'As am I.' Teal'c agreed from the other side of the chair.

There was a comfortable silence for a moment.

'How much longer do you think we're going to be stuck here?' Jack asked.

A bright flash of light filled the chamber.

A disorientating moment later, Jack staggered as he re-materialised on the bridge of an Asgard ship. The first thing he checked for were his team-mates and his heartbeat settled as he saw Daniel, Teal'c and Sam.

'Greetings, O'Neill.' A high pitched voice informed him ahead of the appearance of its owner; a small thin grey alien with a large head and black eyes.

Jack grinned. 'Thor. It's good to see you buddy.' He leaned down to shake the alien's hand gently.

'It's good to see you again although I wish it were under better circumstances. I have bad news.' Thor said.

'About Colonel Carter?' Jack asked in trepidation his brown eyes flickering to Sam's startled blue ones.

'No,' Thor shook his head, 'I will not know until I examine her what has happened to her physiology since the encounter you described with the Ascended being.' His eyes blinked slowly at the human he considered a friend. 'I was referring to the Replicators.'

'Oh.' Jack said. 'That. Well, we know about that.'

Thor's brow creased a little although it was difficult to tell. 'You are already aware of the Replicator ship headed for Earth?'

Jack's mouth gaped open. 'No.' He admitted in an outraged voice. 'I was not aware. I was talking about the human form Replicator getting together with Ba'al.'

'The human form Replicator has allied with Ba'al?' Thor frowned. 'That might explain why she has woken her brethren.'

'Woken her brethren?' Sam asked trying to ignore the pounding in her head.

'Two days ago we picked up a signal from a remote part of our galaxy. When we investigated it our scout ship discovered a Replicator ship. We had not picked up its signal previously in that area of space. We believe the human form Replicator kept them hidden in our galaxy in an inactive state to ensure some of her brethren survived in the event that she was defeated in her battle against the Goa'uld.'

'A sensible precaution.' Teal'c noted.

'Yeah, great.' Jack said dryly. He pushed his hand through his hair. 'We need to contact Earth.'

'I have already informed General Hammond.' Thor said. 'He requested that I recover you from Dakara and bring you back to Earth with me where I will stay to assist you.'

'I cannot leave Dakara.' Teal'c said. 'It is facing an imminent attack from Ba'al.'

'That's it!' Daniel said fiercely. 'That's the plan!'

They all stared at him.

'What?' Jack asked finally wondering whether he wanted to hear the answer.

'Ba'al was trying to break our alliance with the Jaffa apart – why?' Daniel began pacing as he answered his own question. 'Because he knew that we would help the Jaffa hold Dakara. He allied with the Replicator because she offered him an alternative way of ensuring we wouldn't get involved. We'll be busy defending ourselves against the Replicators while Ba'al attacks Dakara; the Jaffa will be without our assistance just as effectively as though Ba'al had broken our alliance.' He stopped and whirled to face them.

Sam sighed. 'The attack on Earth might help Ba'al but ultimately it's personal for her.'

Jack's brown eyes focused on the blonde Air Force officer and he felt a chill work its way down his spine at the total confidence she had spoken with. 'Why?'

'Because we defeated her.' Teal'c commented thoughtfully.

Daniel pointed at the Jaffa. 'He's right. She's furious that we defeated her.' His blue eyes landed on Sam. 'More than that she knows it was Sam who defeated her.'

'How could she even know it was me at Dakara?' Sam said desperately.

Daniel had a flash of memory; Sam behind a line of Jaffa, her P90 raised and spitting bullets at the approaching mechanical bugs her Replicator double had sent to take Dakara. 'She knew you were there. She saw you through the other Replicators.'

'How do you know that?' Jack said.

'I told you at the debriefing, Jack, I was inside her head; she was inside mine.' Daniel sighed. 'All she wants is to rule the galaxy and create more Replicators. I think she's allied herself with Ba'al because it will weaken him and the Jaffa. Until her brethren get to this galaxy she doesn't have an attack force herself. With us under attack, Ba'al and the Jaffa fighting each other, all she has to do is stand back and wait for her moment to take Dakara herself.'

'OK,' Jack said, 'so we need to get back to Earth and start planning how we take her out once and for all.' He looked over at Teal'c. 'Sorry T.'

Teal'c inclined his head. 'I will need to transport down. I must stay and help hold Dakara.' He said. He clasped Jack's forearm and held it for a moment. 'I wish you well in your battle.'

'Back at ya, Teal'c.' Jack said.

Sam crossed over and gave the Jaffa a hug goodbye. Daniel did the same

Jack gestured at Thor. 'I need to talk with the Jaffa Council too.'

'I am ready, O'Neill.' Thor said waving a thin hand.

Jack stepped into the holographic circle as Teal'c disappeared from the ship. Their sudden appearance inside the Jaffa Council chamber caused a great deal of shock and there was a moment of confused noise before the Jaffa settled down again.

'Teal'c, O'Neill.' Bra'tac nodded at them relieved. 'We thought you were trapped after you had successfully destroyed the weapon.'

'Well, we haven't exactly destroyed it, we've moved it into another dimension and yes, we were stuck.' Jack confirmed. 'Fortunately, Thor, the Supreme Commander of the Asgard fleet came by and beamed us up.'

'That is indeed fortunate.' Bra'tac said trying to sound sanguine.

'Unfortunately, his reason for stopping by isn't good news.' Jack said gesturing at them, his holographic image flickering. 'There are Replicators on their way to Earth. We have to leave immediately. Obviously Ba'al and his little Replicator friend have come up with this as a way of dividing us as a force.'

'The Jaffa can defend Dakara against Ba'al without the Tau'ri.' Gerek growled across the table.

'I'm sure you can,' Jack agreed, 'but Ba'al knew it would be more difficult for him if you had an ally.' He sighed. 'We don't think they'll be able to get to the weapon but there's always a chance.'

'The Tok'ra will continue to stay and help defend Dakara with the Jaffa.' Delek said.

Jack nodded. 'We'll take care of the Replicator and make sure she doesn't get to Dakara.'

'We will miss you in the fight,' Bra'tac said sagely, 'but we each fight the enemy we know best, hmmm?'

Teal'c stepped forward turning to look at the holographic image of his friend. 'If Ba'al or the Replicator succeeds in taking Dakara all that we have fought for will be lost.' He pressed his lips together briefly. 'Good luck, O'Neill.' He raised a clenched fist across his chest in a traditional Jaffa salute.

'Good luck to you too, T.' Jack nodded at the gathered Jaffa and at the Tok'ra before he stepped out of the circle and his holographic image disappeared from the chamber.

'Thor, we still have a team-mate and other people on Dakara, do you think…?' Jack hadn't finished his sentence before there was a flash and Mitchell appeared on the ship next to Daniel.

'Woah,' said Mitchell his head swivelling wildly as he tried to get his bearings.

'The rest of your people have been transported to the cargo hold.' Thor confirmed.

'I'd better go down and explain things to them before they panic.' Daniel said gesturing at the door. 'Or start pressing buttons.'

Jack responded with an absent word of thanks as the archaeologist disappeared.

'Wow.' Mitchell said finally. 'So this is…'

'An Asgard ship.' Sam supplied. 'And this is Thor, Supreme Commander of the Asgard Fleet.'

'Pleased to meet ya.' Mitchell said with an awed smile.

'Thor, this is the new member of SG1, Lieutenant Colonel Cameron Mitchell.' Jack said introducing him properly.

'I am also pleased to meet you.' Thor said holding his hand out for Mitchell to shake.

'Do you ever get used to that transportation thing?' Mitchell asked Sam who smiled back at him sympathetically and brought him up to date on events.

'Our journey to Earth will be short.' Thor continued gesturing at Sam. 'Perhaps I can use the time to examine you.'

Sam attempted a smile. 'Thanks, Thor.'

'This way.' Thor led the way off the bridge and within minutes Sam found herself encased in an Asgard medical pod. Her other team-mates hovered anxiously by the monitor where Thor had positioned himself. They were joined by Daniel a few minutes later.

'How are the geeks doing?' Jack asked.

'Thrilled to be on an Asgard ship.' Daniel replied. 'How's Sam?'

'My headache's much better and my hearing is fine,' retorted the military officer, annoyed that he had directed the question at Jack when she was lying right in front of him.

Daniel blushed. 'Sorry, Sam.'

'Interesting.' Thor said.

'What?' Jack and Daniel asked at the same time.

Thor padded over to Sam and waved some kind of metal instrument over her. 'I am detecting a much higher rate of synaptic activity than a normal human brain.'

'Would this show up in her brain wave pattern?' Jack asked thinking back to the results of Carolyn's tests.

'It is possible if the measuring instrument was not sensitive enough.' Thor agreed. 'Typically humans only use five to ten per cent of their brain; I am seeing twenty per cent coverage.'

'Can you…uh…reset it?' Sam asked hopefully.

'I cannot.' Thor said regretfully.

'Is it harming her?' Jack forced himself to ask the question.

'I do not believe so. The ultimate effect is to make the brain operate at a higher rate of efficiency,' Thor said, 'but I have never come across this before. The Asgard were a young race when we came into contact with the Ancients. Much of their technology is still beyond even our understanding.'

'Maybe it's a good thing.' Daniel suggested. 'Maybe it speeds up your thinking and that's why you were able to build the counter-measure.'

'Maybe.' Sam said noncommittally. 'Will someone give me a hand out, please?'

Mitchell assisted her before Jack could move and he swallowed his jealousy at the easy familiarity between Sam and the younger man reminding himself again that there was no need for it.

'Thor,' Sam said brushing off the front of her green jacket, 'do you still have some of the inactive Replicator blocks?'

'I do.' Thor confirmed.

'We should access the Replicator network again and see if we can determine the frequency we need to set the disruptor wave to.' Sam suggested. 'If there is only one Replicator ship, we should be able to destroy it using your ship before it can alter its frequency.'

'I agree.' The small alien said solemnly.

'I'll help.' Daniel offered. 'There may be something in my head from being in hers that might help.'

Jack and Mitchell headed out to find food and check in on the scientists while Sam, Thor and Daniel worked.

'There!' Daniel pointed at a section of data.

Thor isolated it on the screen. 'It is the cipher.' He gestured at them. 'Please continue. I need to make some navigational changes. I will return shortly.'

'Good work on identifying the cipher.' Sam said. 'It took us forever last time to isolate it.'

'I recognised it.' Daniel admitted.

'You've never talked much about your experience with the Replicator.' Sam commented.

Daniel looked across at the console at her. She had her eyes fixed to the Replicator blocks under a force field and her tone had been casual but he knew it was anything but a casual question. 'I was worried it would upset you.' He admitted folding his arms.

Sam looked up at him. 'I'm sorry.'

'Why are you sorry?' Daniel asked. 'It wasn't your fault.'

'Wasn't it?' Sam asked. 'If I hadn't betrayed Fifth, she wouldn't even exist.'

'From what I understand you were following orders, Sam.' Daniel said gently. 'If you think about it, it's really all the Asgard's fault.'

'What?' she asked taken aback.

'Well, if they hadn't trapped the Replicators with a time dilation device, the Replicators wouldn't have evolved into the human form versions in our life time. You would never have met Fifth and this wouldn't have happened.'

'That's an interesting theory.' Sam said. 'So you think I should blame the Asgard?'

'I think you shouldn't blame yourself.' Daniel replied.

'I'll make you a deal.' Sam suggested. 'I won't blame myself for her if you don't blame yourself about her ascending and coming back.'

Daniel made a face but he nodded.

'Do you remember any of it?' Sam asked.

'What?'

'Well, if she was in your head digging out all the stuff you have buried about being ascended, don't you remember any of it?' Sam asked. 'I mean you obviously remember being in her head.'

Daniel shook his head. 'I don't remember much.' He sighed. 'I think they buried it all again when I came back.'

'But you remember being in her head?' Sam checked.

'I do.' Daniel said. 'Actually, there wasn't any trick to it. All the Ancient knowledge did was remind me that because we were in this weird mental link I could influence what happened there as much as she could.' He shook his head. 'I was able to receive the same information as she was and because we were one mentally I could direct the Replicators through her link with them.'

'You saved us.' Sam said.

'I couldn't hold the Replicators for long. It was too much for my brain to handle.' Daniel said sadly. 'There were so many of them.'

'If it hadn't been for you holding them up for that moment, we wouldn't have made it.' Sam said.

The ship's vibrations changed subtly.

'We're out of hyperspace.' Sam said. 'We're home.'

The next thing both of them knew they were in the briefing room of the SGC with Jack, Mitchell and a very surprised General Landry.

'It's good to see you, Jack,' Landry said recovering his composure quickly. His brown eyes moved from the General to the other three people who had just appeared in the briefing room. 'And the rest of you. I take it Teal'c stayed on Dakara?'

'Yes, sir.' Jack waved at the team to sit and they took their places at the briefing table.

'General Hammond got recalled to Washington.' Landry explained seeing the unasked question in Jack's eyes. 'I'm afraid you're stuck with me.' He smiled taking the sting out of the words and waved at Jack. 'I know you're better equipped to handle this than I am so I'll just try not to get in your way.' He finished wryly.

Jack smiled but he didn't dispute the remark. 'Thor's hiding his ship. He's going to act as the cavalry once he finds the right setting for the disruptor weapon. What have we got here, sir?'

'The base has been evacuated of all non-essential personnel.' Landry said. 'We've already sent as many people as possible to the Alpha site. Thor estimates another day before the Replicator ship arrives. Prometheus will be ready to launch in twelve hours; she'll be the first line of defence. What's the status of the Ancient weapon?' He asked. 'Were you successful in destroying it?'

'Actually Carter moved it into a different dimension, sir.' Jack corrected.

'Into a different dimension?' Landry repeated, his bushy eyebrows shooting up. He stared at Sam who tried to maintain a blasé expression. 'Is it safe?' He asked a little alarmed.

'Yes, sir.' Sam confirmed. 'We shouldn't require the counter-measure I built.'

Landry smiled at her. 'You'll be pleased to know it passed all your tests so although we don't need it, I still consider it an outstanding achievement.'

Jack winked at her proudly. 'I don't know, sir, I'm thinking the moving the weapon into a different dimension may just top creating a counter-measure to it.'

'I think I agree with you.' Landry said with a smile.

Sam pursed her lips thoughtfully. 'Sirs, I think I have an idea.'

'Don't keep us in suspense, Colonel.' Landry ordered.

'I think I could modify the counter-measure for the Ancient weapon to emit a series of static disruptor waves. It could act like an invisible iris destroying the Replicators as they try to come through the Stargate.' Sam explained. 'If I can create layers instead of one, the first could act to determine the required frequency...'

Landry waved his hand cutting off her explanation much to Jack's amusement; it was usually him. 'You can create a new counter-measure to the Replicators?'

'I think so, sir.'

'Go ahead and build it, Carter.' Jack ordered. 'Use anyone and anything you need.'

Sam nodded in confirmation. 'Has there been any news from Dakara?'

'Nothing yet.' Landry said. 'We think Ba'al and the Replicator will coordinate their attacks simultaneously.'

'Makes sense, sir.' Mitchell murmured.

'Our orders, Jack, are to hold the mountain for as long as possible to give Thor a chance to modify his weapon so he can take out all the Replicators in one shot.' Landry confirmed.

'Understood, sir.' Jack nodded. 'Mitchell, as Carter will be busy having fun with her counter-measure,' his eyes briefly flickered to hers and he was rewarded with a smile, 'I'm going to need you to organise a…'

There was a flash of light that filled the briefing room and blinded everyone at the table for a moment.

Sam's eyes snapped back to Jack; he was gone and a six-legged metal bug sat in his place.