A/N: Two more chapters should be upcoming, wrap-up and closure. Although, if I draw things out like I normally do, I suppose it could possibly turn into three chapters. I hope you all enjoy the wonderful angst in reading this chapter as much as I enjoyed writing it.

P.S. - Careful readers might also note some dialogue with a slight resemblance to that in a scene in the season 3 episode 'Irresistable'. It wasn't quite intentional, but seems to work well IMHO.

P.P.S. - I made another change, leading from a small change in chapter 10, to the flow of events here in chapter 11. John now has Epi-pens full of serum and may be forced to use them!

"Ronon, Lorne, you're with me," John ordered casually. "Teyla, you and the others stay here and guard the generator."

"John!" Teyla exclaimed insistently, placing a firm hand on his arm. "Rodney is very intelligent. We must not become separated!"

"Guard the generator," he reiterated gently, but persistently. She hesitated for a moment, then begrudgingly stepped back into the doorway.

John's heart pounded in his ears as adrenaline rushed through his veins. Ronon and Lorne moved with him as he slowly paced his way down the hallway in the direction the sound had emanated. He could hear the faint hum of power generation fade as the lights that illuminated the corridor went dark. Obviously Rodney's assistants knew what they were doing, and power was again being routed to the control room. John's confidence climbed a bit with the thought that Elizabeth would now be able to help him track Rodney and Carson, and he was comforted knowing that she was watching his back.

With his P90 leveled straight ahead, John stopped at the edge of an intersecting corridor and peered around each corner, but saw no signs of anyone in any direction. If someone was out there stalking them, splitting up would have been a seriously bad lapse in judgment. He decided it was better to err on the side of caution and instead activated his radio.

"Control room, this is Sheppard," he called, but did not receive a response. "Control room, please respond. Elizabeth, are you there?"

He waited for another terse moment, then tried a different channel. "Control room; is anybody paying attention up there?"

"Colonel Sheppard!" A frantic reply came suddenly; John thought he recognized the voice as belonging to one of the night-watch officers that manned the consoles. "We need assistance in the control room immediately!"

"Evans? What the hell is going on up there?" John demanded, frustration edging its way into his voice.

He could hear the tech frantically shouting orders in the background. "Sir, they blew out the lock on the door! People are hurt up here!"

If it was Rodney causing havoc to the generators, it must have been Zelenka.

"Calm down," John urged as his heart jumped into his throat. It seemed that all the business with the generator had been a distraction. "Now tell me exactly what happened."

"An incendiary device had to have been planted behind the door," he explained, taking a large gulp between breaths. "Dr. Weir was hurt in the blast and is unconscious. Oh God! They're coming through!"

The sound of machine-gun fire erupted over the com-link, their terrified screams echoing in his ears, and then it all faded far too quickly into silence. The line went dead a second later. Shock began to set in as he took a deep breath, a few remaining beads of sweat dripping precariously over his eyebrows and into his eyes.

"Let's go," he said, mentally shaking off the anxiety that was building up in his mind as they trotted earnestly back to the south lab. Teyla greeted him with an even more deeply concerned appearance than before. She must have heard the disturbing exchange over the radio.

"I'm not giving up just yet." John was planning desperately; he was sure he had just come up with a good idea. "We can't let them keep the control room. Teyla, you and your team need to guard this generator at all costs. If we lose the life-sensors again, we'll lose the whole city."

John next turned to Major Lorne and handed him a vial of serum that he had obtained from Dr. Biro. "Lorne, you, your team, Ronon, and I will head to the control room and take it back any way we have to."

Ronon spun and charged his stunner, seemingly anxious to finally be on the offensive again for a change. John left Teyla's worried look behind him as the six of them jogged off to meet the promise of retaking the control room.

Teyla took a few moments to glance around at her three other teammates, which still included Rodney's assistant standing next to her, and noted that two of the others seemed quite young. Their nervous demeanors were all too apparent, and as she managed to catch their wandering eyes with her inspection, she gave each of them an assuring nod of confidence. She listened carefully for any sign of an attack, but managed to hear only their own footsteps echoing through the corridors as some of them shifted their feet nervously.

The chime of a door opening echoed across the corridors once more. Teyla raised her P90 in the direction of the sound, stepping protectively in front of the young scientist. The other two marines in her team guarded the door on the opposite side of the lab. Slow, determined footsteps began to echo eerily throughout the expanse of the corridors before them, making it difficult to tell exactly which direction they were coming from.

The young lieutenant on the other side began to panic, his breathing becoming labored as he peered around in either direction of the hallway in front of the door. The marine shrieked with fear as a figure finally darted out from the shadows not five meters in front of him. Carson Beckett reached out a hand and as fast as lightning had the neck of the petrified soldier in his grip. He let off a few rounds with his weapon as he gasped for breath, some of which passed through the flesh of his foe's leg, but it did not faze him at all. The bullets simply left behind dark abrasions; blackened blood dribbled almost imperceptibly from each one.

The young marine's comrade turned and without thinking emptied at least half of his clip into Carson's body. Annoyed and still unfazed, Carson tossed the hapless lieutenant into the other soldier, watching with a cruel smile as they crumpled to the floor unconscious. He next turned his attention to Teyla, his smile fading.

Teyla took a step back and turned her head to order the frightened scientist away. "Run," she commanded firmly, raising her weapon. "Go now!"

The tech didn't need to be told twice and took off running down the corridor in the direction that Colonel Sheppard's team had left. Teyla turned back to face Carson, his anger overflowing uncontrollably as he edged closer to his objective with each step.

Her finger tensed for a moment on the trigger, hesitating. This was Carson, her friend. Teyla trembled, and was unsure she could bring herself to attempt to kill him. It wasn't his fault, after all. His mind simply wasn't able to assert itself any more. She tried to tell herself that it was no longer Carson that she faced, tried to assure herself that there was no other way. She could not allow him to disable the generator!

As John ran alongside his teammates headed to the control room, a sudden realization stopped him in his tracks. He had forgotten to give Teyla a vial of serum! Her P90 would be next to useless against anyone infected.

Ronon slowed to a halt, turning around in curiosity. "What is it?"

"Go on without me," John ordered, grabbing for a vial in his pocket and tossing one of the remaining two to Ronon. "I have to go back for a minute."

Ronon shrugged in confusion, but obeyed.

Teyla's fingers pressed the trigger. She emptied her entire clip into his chest, then took a few steps back and desperately reloaded her weapon. He kept coming closer, completely unaffected. She emptied the next clip into his chest - nothing. There was no indication that he had felt anything at all. Her trembling hands sank down, the P90 in her hands falling to her side despairingly as she felt the wall against her back.

A wave of terror and helpless panic seized her as Carson coldly reached out for her neck and began to squeeze mercilessly. His eyelids drooped, engrossed in the narcotic-like euphoria. Tears rolled down Teyla's face as she was forced to gaze into his pale-green eyes, which were oddly shadowed by regret and fear while the rest of his features remained emotionless. She fought desperately against his iron grip, struggling to breathe as his mucus-drenched hands choked the life from her.

A moment later, Carson's face contorted with more surprise than pain, and his grip faltered. He fell to his knees, but was not stunned for long. He swiveled around to face the person that had attacked him from behind. Teyla scrambled for safety, coughing and sputtering, as Carson seemed to realize with some anxiety that Sheppard had not left for the control room after all. John stumbled backward, dropping the injector that he had just emptied into Carson's arm, and readied his P90.

John held up a hand, holding back his next attack for the moment. The corridors in either direction stretched on long enough that he would still have a clear shot if his target tried to run. Carson's brow furrowed. He trembled with fear, and John saw telltale signs of tension that looked to indicate he was about to bolt.

"Carson, please don't—," John implored, taking a small step toward him. "You don't have to run any more."

His sweat-soaked face slowly transfigured itself from a state of shocked rage and fear to regret and confusion. Carson was hyperventilating, on the brink of running away screaming in panicked terror. It seemed like he wasn't quite able to decide what to do, though, which gave a small ray of hope that he wasn't yet completely beyond help.

John took another small step toward him.

"No!" Carson shouted as he backed up against the wall, trembling violently.

Halting for the moment, John took a deep breath and relaxed his posture a bit, trying to assume an aura of compassion and understanding and slowly bent down to help Teyla up to her feet as she regained her breath. She took his hand, grateful for the assistance. Taking out a kerchief from within his vest, he helped clear her neck of the coating of yellow-green mucus that had been left by Carson's hands and inspected her airway for any obstruction. She would have some nasty bruises, but didn't appear to be life-threatening.

Carson watched the interchange with mild interest, hanging his head in shame as Teyla leaned back to rest against the opposite wall near the two fallen marines and waited patiently. He honestly hadn't wanted to hurt her. He felt ashamed and abhorred with himself that he hadn't been strong enough to stop it from happening. Tears welled in his eyes as grief and fear overwhelmed him, once again threatening to overtake his conscious mind with the primal urge to run, hide, and hurt the people around him.

"You can fight this," John encouraged, not daring to move another muscle. He was growing more concerned that Carson would attempt to run, but he was becoming more optimistic by the fact that he at least seemed to be listening.

"I can't!" Carson cried.

"You can!" John insisted. He took another hesitant step forward and slowly reached out a hand. "Take my hand, Carson. I'll take you to the infirmary myself."

Carson shook his head disagreeably. "I can't... you'll... you'll become..."

"I'd already been infected on the planet, Carson," he explained slowly. "I'm now immune, so you can't infect me again."

Carson's eyes glazed over in confusion. His gaze shifted back and forth from Teyla to John. He just couldn't seem to think straight. His eyes quickly traveled up and down John's form, noting inconsistencies. He couldn't fathom how it was possible for him to have been infected and show no symptoms. John was hardly sweating at all.

John didn't have time to go in depth, as the orderly had. "My body had enough time to start producing anti-bodies. Dr. Biro's already finished making the first batch of serum to treat you. Use your head! Think about what I'm saying!"

Carson swallowed hard, unsure of what to think.

"Would I be offering you my hand if I thought I would become infected?"

He could not refute John's logic. Slowly, tentatively, Carson reached out a filthy and shaking hand to meet John's. John gripped the proffered hand firmly, despite the gooey mucus, and stepped closer to put a comforting hand on Carson's shoulder.

"Everything's going to be okay," John whispered gently, squeezing gently.

"So tired…" Carson mumbled sleepily as his knees buckled underneath him. Trying to support his friend, John nearly collapsed with fatigue himself. Carson's head rolled forward limply in John's arms as he struggled with the dead weight.