Sam now sat on the stool, a bandage pressed to his chest. Angel and Dean had the doctor check his wound and bandage it when they filled her and Duane in. His eyes were down, and he looked near tears as the others surrounded him. From the door, Mark and Duane eyed the youngest Winchester like he was a ticking time bomb. The doc had her head down several feet beside Sam. Angel was right next to her little brother, looking down at him worriedly as she rubbed his back, her free hand resting on his arm.

Dean paced angrily and just as worriedly, "Doc, check his wound again, would you?" Dean came to a stop in front of Sam who wouldn't meet his or Angel's eyes, and barked at the doctor when all she did was stare at Sam in fear, "Doctor!"

She jumped at him but shuffled over to Sam as Mark stepped forward, "What's she need to examine him for? You saw what happened."

Dr. Lee took a breath and looked into Sam's eyes, "Did her blood actually enter your wound?"

"Come on!" Mark bellowed, "Of course it did!"

Angel glared, "We don't know that for sure!"

Duane interjected, "We can't take a chance."

"You know what we have to do."

Dean studied the two shuffling men, dismissing them with a hard look, "Nobody is shooting my brother."

"He isn't gonna be your brother much longer." Duane stressed, "You said it yourself."

"Hey!" Angel yelled before Dean could, locking the two strangers with a warning, "Nobody is shooting him, end of story."

Duane angrily pointed at Dean, "He was gonna shoot me!"

Fire showed in Dean's eyes as he took a step toward Duane, only stopping when Angel grabbed his arm from behind, "You don't shut your pie-hole, I still might!"

"Guys…" Sam's voice cut through the yelling, pleading to both of his siblings, "They're right. I'm infected; just give me the gun and I'll do it myself."

Angel tensed, "Sammy-"

Dean instantly dismissed him, his eyes softening when he looked to Sam, "Forget it."

Sams centered them with a determined eye, "I'm not gonna become one of those things."

"Hold on- just hold on a minute." Angel wiped her face, racking for something in her brain, anything that could help, "No ones dying right now. We- we can figure something out. We've still got time."

"Time for what?" Mark scoffed at them from the other side of the room before turning his hard eyes to Angel and Dean, "Look, I understand he's your brother, and I'm sorry, I am." Mark pulled his handgun out causing Sam to stiffen up, "But we gotta take care of this."

Within a beat of a second, Angel was instantly in front of Sam with her gun out, cocked and pointed at Mark, rage in her eyes, "You make one move on him and you'll be dead before you hit the ground!"

"Did you hear her? Dean held that same fire in his gaze, "Is that clear?!"

Sam looked between them, "Guys!"

Mark's own voice rose as he grew more and more frustrated, "Then what are we supposed to do?!"

Dean turned back to Sam, studying him before sending a look to Angel and tossing Mark his keys, "Get the hell out of here, that's what. Take my car. You've got the explosives, there's an arsenal in there." He looked between Duane and Dr. Lee, "You two go with him. You've got enough firepower to handle anything now."

Sam looked from him to Angel in shock as the blonde lowered her weapon and nodded at Dean that she agreed with the plan.

Mark looked between them, "What about you two?"

Angel and Dean shared a knowing look before they each turned to Mark with conviction in their eyes. His mouth dropped as he realized what they were doing.

"Guys, no." Sam whispered pleadingly, "No. Go with them. This is your only chance!"

Dean smirked down at him as he shook his head, "You're not gonna get rid of us that easy."

"No, he's right." Mark shook his head, "Come with us."

"No…" Angel shook her head, coming to stand next to Sam, who had more tears forming in his eyes, before looking at Mark, "We're staying."

Mark's shoulders slumped and his face went tight, "Okay, it's your funerals."

Dean led them out the door, and Dr. Lee stopped at the entrance, "I'm sorry." She looked at each of them, "Thanks for everything, Marshalls."

"Oh, actually…" Dean shook his head, "We're not really Marshals."

"Um." She frowned, "Oh."

When she left, Dean shut and locked the door behind her. He turned slowly to face Sam, who started to cry from beside Angel.

"Wish we had a deck of cards…" Dean shrugged, forcing a chuckle, "Or a foosball table or something."

"Guys, don't do this." Sam cried, "Just get the hell out of here."

Dean shook his head, "No way."

"Give me my gun, and leave."

"Sam." Angel snapped, "For the last time, no. We're not going anywhere."

Sam slammed the table beside him, "This is the dumbest thing you two have ever done!"

"Psh, i seriously doubt that." Angel crossed her arms, "Remember that time in Tampa when Dean and I met those twins? Uh… Bethany and Bobby?"

Dean shuddered at the memory as Sam looked down, "I'm sick. It's over for me but it doesn't have to be for either of you. You guys can keep going."

Dean's jaw clenched, "Who says I want to?"

"What?"

Dean crossed to the other wall and pulled a handgun out of his waistband before sitting on the file cabinet, "I'm tired, Sam. I'm tired of this job, this life… this weight on my shoulders. I'm tired of it." He met grim eyes with their older sister, a look Sam didn't miss, "I think we both are."

"So what, you two are just going to give up? You're just gonna lay down and die? Look, I know this stuff with Dad has-"

"You're wrong." Dean interjected, "It's not about Dad. I mean, part of it is, sure, but…"

"What is it about?"

Before he could answer, they heard a noise outside. A moment later there was a knocking on the door. Dean picked up his gun as Angel readied hers. She opened the door to reveal the doctor.

"You'd better come see this."

Angel shared a look with her brothers before they followed. All six survivors stood just outside the clinic; everything else in sight was deathly silent.

"There's no one. Not anywhere." Dr. Lee explained, "They've all just… vanished."

The next morning…

Dr. Lee looked through the microscope as Sam was seated on the exam table, "Well, it's been five hours and your blood's still clean. I don't understand it but I think you dodged a bullet."

"But I was exposed. How could I not be infected?"

"I don't know. But you're just not. I mean, you compare it with the Tanner samples…" She looked through another microscope and frowned, "What the hell?"

"What?"

"Their blood. There's no trace of the virus. No sulfur, nothing."

Outside the clinic…

Mark and Duane loaded up a truck as Dr. Lee stood in the doorway of the clinic.

"Hey, the Sarge and I are getting the hell out of here, heading south." Duane said to her, "You should come."

"I'd better get over to Sidewinder, get the authorities up here. If they'll believe me." She waved, "Take care."

Mark waved to her and to the Winchesters who were leaning against the Impala.

Angel earned the doctors attention, And our brother?"

"He's going to be fine." She smiled, "No signs of infection."

She went back inside as Mark and Duane pulled away in the truck.

Dean turned to Sam who put his arms up, "Hey man, don't look at me. I got no clue."

"I swear, I'm gonna lose sleep over this one. I mean, why here, why now?"

"Also…" Angel looked between them with wide eyes, "Where the hell did everybody go?"

"Yeah! It's like they just friggin' melted!"

Sam glanced between them, "Why was I immune?"

"Yeah. You know what? That's a good question." Dean shook his head, "You know, I'm already starting to feel like this is the one that got away?"

The three of them got in the impala and pulled away from town.

On the road…

Mark drove his pickup down a dark two-lane road with Duane in the passenger's seat.

"You mind pulling over up ahead there?"

Mark pulled onto the shoulder and stopped the truck, "Alright."

"I gotta make a call."

Mark gave him a confused look, "No phone out here."

"I got it covered."

When he pulled out a small knife, Mark looked at him crazily, "What the hell is that?"

In a quick motion, Duane lashed out, slitting Mark's throat. He caught the blood in a metal bowl, just like the one Meg used to use and sat back, dipping his hand in the blood and swirling it around. Duane's eyes went demonic-black as he spoke into the bowl.

"It's over, you'll be pleased. I don't think any more tests are necessary." He smiled down into the bowl, "The Winchester boy, definitely immune, as expected." He paused, "Yes, of course. Nothing left behind."