Disclaimer: Not mine.

Goes very AU from the Croatoan ep. Wincest.

Chapter 1

Dean stared at his little brother sitting slumped on the examination table, casted arm covering the wound on his shoulder even as everyone argued over what to do. But all Dean could do was watch his brother, terror gripping him as he watched and waited to see if Sam was infected. Sam looked up at him, eyes watering, and Dean moved to his side, reaching out to grip his hand and Sam managed a small smile. "It's gonna be okay Sammy, you're going to be fine." He whispered and Sam shook his head.

"You suck at lying." He responded, fighting tears. "Dean don't do this, just give me my gun and leave. Get them to safety."

"No, I can't do that." Dean answered, leaning in to kiss him while everyone was distracted and Sam kissed him back, kissing him goodbye.

"Dean please, you can't die here. You have to live, for me." Sam pleaded, he felt funny. Sort of hot and he was terrified, he had to make Dean leave before it was too late. Dean squeezed his hand and then went over to the others, telling them to take the weapons and go. They argued but eventually left and Sam choked on a sob, shaking his head. "No, you have to leave Dean. Now! Please." He couldn't bear the thought of hurting Dean, even knowing that by then he wouldn't care. He'd seen what this thing did to the others and he hated the very idea of ending up like them.

"Sam?" Dean asked in alarm and Sam looked at him, terror in his eyes. Dean hated seeing Sam so scared and this time there was nothing he could do to fix it.

"I….I think…please Dean, I don't want to hurt you." He whispered and Dean moved closer, wrapping his arms around him and Sam sagged against him, trembling. "Please Dean; give me my gun before it's too late." He begged shakily, feeling it spreading, he had to act before it reached his mind and changed him.

"Sammy…" Dean choked out, refusing to cry. He would not cry, he would find some way to fix it. He couldn't lose him. If Sam died then he might as well eat a bullet after.

"Love you, now please go." Sam lifted his head for a final kiss.

Dean kissed him, tasting Sam's tears. "I can't leave you." He breathed, heart breaking.

"You have to." Sam answered and then fell silent. The heat rushed through him, making his vision swim, everything feeling odd, disjointed and then Sam moved, shoving Dean away and lunging for a scalpel.

Dean stumbled back and then stared in shock as Sam went for the blade but instinct kicked in and he raised his gun. "Don't do it Sam, please." Sam sneered at him and he knew it wasn't his brother anymore but the Croatoan virus in him.

"Should have killed me when you had the chance Dean." Sam told him as he pinned the older male to the wall, Dean struggling against him madly.

"Fight it Sam, please. You're stronger than this." Dean begged his brother to fight for them.

"Don't worry Dean, everything will be fine." Sam raised the blade and Dean realised what he was going to do, he was going to infect him.

"Sammy." Dean gasped as the blade sliced through the skin on his collarbone, well away from his throat. The blade was so sharp that it didn't hurt at first but then the stinging pain kicked in even as he felt warm red blood trickling down his skin from the shallow wound. Sam raised his hand to his own wound and then hesitated, blinking rapidly. "Sam please don't do this." Dean whispered, seeing the hesitation. He collapsed as Sam struck him, lying dazed against the wall and then he scrambled for his gun even as Sam moved away from him. He looked up at Sam who stared back before taking off. "Sam!" Dean staggered up and after him but by the time he made it out of the clinic the streets were empty. "SAM!"

There was no answer to his desperate scream but Sam hesitated briefly in his mad run through the trees. Part of his heart cried out to turn back, to go to him but if he did…no, he had to keep running.

Dean just stared around the deserted town dazedly before stumbling to the Impala and crawling into the back seat to sleep, his head pounding. He needed to rest before attempting to leave the town and go for help before this thing spread too far out of control. Bobby, he would go to Bobby's.

TBC…..