What if Bobby got the Croatoan virus?
"The Winchesters are here," one of the demons informed another one.
"Great, we'll roll out the red carpet."
"This virus is airborne, right?" the first demon asked.
"Yes, we were successful with the mutation. It still takes a few hours to take affect, but luckily, we exposed most of the workers here a few hours ago."
SSS
Sam and Bobby crept up to the door. It was locked. Sam picked the lock and they snuck in. They trusted that Cas was doing his part.
A demon popped up next to Sam. He plunged Ruby's knife into his heart. They heard some noise. "Stay here," Sam said and handed Bobby the knife.
"Sam, wait," Bobby hissed. Dean had told him to keep Sam safe.
"Just wait here," Sam said. Bobby had only had the use of his legs for a couple of hours. He would be better off guarding the door while Sam went after the civilians trapped with the Croatoans.
Sam walked back and found five people trying to climb out the reach of two enraged croats. Sam pulled out his gun and shot them. The civilians continued to cower on the racks that they had climbed. "Come on. It's OK, we'll get you out of here," he promised.
SSS
Bobby heard shots. He wanted to go help Sam, but suddenly a demon appeared in front of him. He thrust the knife into his throat. The demon fell to the ground.
A few minutes later, Sam showed up with about 15 people. "I think this is everybody," he said as he ushered them out.
As the last one exited, another Croat came out of nowhere and tackled Sam. Bobby tried to shoot it, but his gun jammed. As he was trying to unjam it, he heard a shot. He looked up to see Cas standing there with the gun he had given him earlier.
"You're right these things do come in handy," Cas said as he reached down to help Sam get up.
"Can we commit our act of domestic terrorism now?" Bobby asked, referring to them destroying the "flu vaccine."
SSS
Three hours later, the three of them were pulling back into Bobby's yard. The Impala was there, so Dean must have beaten them back. He came out.
"How'd it go?" Dean asked.
"Great. We got all the vaccine," Sam said. He wouldn't mention how many people had died in the process. "Did you get the ring?"
"Yeah," Dean said, holding up Death's ring. "He showed me how they all worked, too."
"That's great," Sam said, surpised that Death had just handed over the ring like that. He guessed sometimes things did go their way. He and Castiel headed inside, while Dean and Bobby stayed outside.
"So, what do you think Death does to you if you lie to his face?" Dean asked Bobby.
"Nothing good, I'm sure. Why? What did you say?"
"I told him I was good with this whole Sam saying yes to Lucifer plan."
"And you're not?" Bobby asked.
"Of course not," Dean said.
"Doesn't matter anyway," Bobby said.
"Why not?"
"Because you're about to die," Bobby said and rushed at Dean.
When the virus had taken affect, Bobby not only felt stronger and violent, he received instructions on what he was supposed to do. Kill Dean. He couldn't resist the instructions, but he could use his brain, and he knew that he would have a better chance of success if he separated Dean from the others. So, he had bided his time, and now he was doing his job.
Castiel was just coming out to see what was keeping Dean and Bobby. He immediately took in the situation and realized that Bobby must have been infected. They should have checked him for cuts. He knew there was no cure for the virus, and he knew if he didn't do something fast, Dean would be dead. He grabbed Bobby's gun again, and shot Bobby.
"What the hell, Cas?" Dean asked.
"He must have been infected. I'm sorry, Dean."
Sam came running out. He had heard the shot. "What happened?"
"Bobby tried to kill me and Cas shot him," Dean explained.
Sam now knew what had to be done. It was official. He and Dean were all they had left in the world. Except for Cas, but he wasn't exactly human. If he were gone, Dean could go have a life with Lisa and Ben. "Dean, I have to say yes to Lucifer. If I don't Bobby died for nothing."
Dean didn't want Sam to do this. If he let Sam do this, he would be all alone. "No, Sam. You can't."
"Dean, I'm going to do this and you can go find Lisa and have a normal life."
Dean realized that he couldn't control Sam. He wasn't his father. Sam was a grown man and had to make his own choices. "Fine."
"We should go now," Castiel said.
SSS
They had jumped some demons and drained them of the blood, so Sam could drink it and prepared to be Lucifer's vessel.
"Do we know where he is?" Dean asked Castiel.
"He's close. He's in town."
"How do you know?" Sam asked.
"I can feel him."
Suddenly, Dean attacked Cas. "Dean, what are you doing?" Sam yelled.
Dean looked up at him and Sam recognized the look. He had seen it on so many people early this morning. He had the virus. Castiel used the distraction to kill him.
"How did he get it? He said Bobby didn't bleed on him," Sam protested.
"The virus must be airborne."
"Oh," Sam said. He figured Cas hadn't gotten it, because he was an angel, and he didn't get it because he was immune.
"Now, I guess I really have to do this," Sam said.
"Yes, that does seem to be the only option," Castiel said.
Sam walked towards the building, never to know how wrong he was. Castiel wasn't immune, but his job was to make sure that Sam would have no emotional base in order to take over from Lucifer.
The End