They'd been worried that Dean wouldn't want a little brother. He was rather attached to both parents and he wasn't the best at sharing anything, really- his first day in preschool he'd given another boy a bloody lip after the boy tried to use one of his cars- so asking him to share his mom and dad seemed like it might be a bit of a stretch for the four year old. They'd been worried, and they'd been wrong.

As soon as he understood that the bump on his mom's tummy, the thing that he could sometimes feel moving, was going to be his brother, he'd grown excited, almost giddy, asking day after day if it was time for his little brother to come yet. They'd tried to keep him involved, asking whether he liked "Sam" or "Jack" better. It had been a definite, quick answer: Sam.

When the day had finally come, Dean had practically been jumping out of his car seat on the way to the hospital. It had been love at first sight. The baby, a bit fussy, had settled down immediately upon locking eyes with Dean. He'd demanded to hold Sam, had clambered onto the bed with his mom, carefully and seriously holding his little brother's head up.

Dean, John had said, crouching next to Dean's head. That's your little brother, Dean. You've gotta keep him safe, okay? You're his big brother, Dean, the only one he'll ever have. Dean had nodded solemnly, brow furrowed into a frown as he cradled his brother more closely to his chest. It was almost comical how the tiny boy took the role of protector so seriously, clearly believing sincerely that he could, and would, protect Sam from anything and everything.

A few minutes later and a nurse had come in to give Sam a shot. She'd had to pry him from Dean's hands, and when the baby whimpered upon being removed from his brother's grasp, Dean had gotten off the bed onto the floor, his stance protective as he glared at the nurse. Then when Sam had started full on bawling- healthy set of lungs, that one- Dean's fists had balled up at his sides and his teeth had been displayed in an unmistakable snarl. John had seen the warning sign, reached out to grab his oldest, acted too late as Dean let out a yell, ran forward, and ferociously kicked the nurse's shin. The nurse had looked down, startled, and Mary had called his name in shock.

Dean, he'd said, Dean, come here. He'd used his no-nonsense tone and Dean had trudged over, head hanging. Dean, say sorry. You know better than that. It had surprised John to see the quiver in his son's lip as he shook his head. That, too, surprised him. Dean rarely disobeyed, virtually never disobeyed a direct order.

Dean, he'd repeated, hoping he was making the warning evident in his tone. Dean had shaken his head again, fiercely, angrily glaring at the nurse. His lip had trembled again, but he'd looked up, meeting John's eyes head on. John had been taken aback by the fire he saw raging in them.

She hurt Sammy! He'd screamed, and burst into tears. I won't say sorry! I won't! John couldn't help but smile as he gathered his sobbing son into his arms, trying to gently explain. He and Mary had locked eyes as the nurse chuckled, the unspoken message passing between them: Sam was in good hands. As Dean settled down after Sam was placed back in his arms, the thought had changed: So was Dean.

Now, as John shoved a screaming Sam, wrapped tightly in a blanket into Dean's open and shaking arms, John looked up for a second, tears streaming down his face. For the last time his eyes locked with Mary's, and the unspoken message passed between them, weaving over and through the pain screaming through Mary's head and the anguish roaring through John's. Sammy's in good hands. So is Dean.

A/N: So I took a little bit of liberty here by saying that Mary was still alive when John told Dean and Sam to get out, not sure if that was the case, but…there it is.