Dean had a vague recollection of Sammy singing. So vague, he was almost certain he's dreamt it. Because he couldn't remember if he'd ever heard his brother sing. Granted, at the moment he couldn't remember much of anything. According to the terse recap Sam had given him, Dean had been out of it for a good 24 hours. Their latest tangle with the supernatural had left Dean with a gnarly headache and a new scar on his left bicep. Sam, on the other hand, appeared relatively unharmed. It was only as he healed that Dean became increasingly aware of the haunted look in his little brother's eyes.

Bobby was the one who, eventually, gave it away. Following their encounter, Sam had dragged Dean to Bobby's, knowing that the grizzled hunter would help him care for Dean. Deep down, he also realized that he would need help treating his own wounds, wounds he fully planned on keeping from Dean.

Sam knew he could swear Bobby to silence for the purpose of not hurting Dean any further. Reluctantly, the hunter agreed, though he almost backed out when he saw the words – words like "demon" "selfish" "alone" and "murderer" – carved into Sam's back. They had been inflicted by someone who knew what they were doing and who intended the marks to scar, permanently etching what Bobby suspected Sam saw as his worst flaws onto his person. But Sam begged, and Bobby relented…until about a week after the boys showed up on his doorstep. A little rest and some good food had worked wonders on Dean, his health improving by leaps and bounds. Dean was back to his old self by the end of the week. However, for every improvement in Dean, Bobby noticed Sam getting worse. He slept little, and ate less, all the while doing his best to hide his distress from his ever-observant older brother.

Deciding, now that Dean was recuperated, that the older brother could take the truth, Bobby stepped in, hoping to stop things from getting out of hand. He knew that Dean had been worried about Sam, that he knew something was wrong with his kid brother, he just didn't know what. So, Bobby "accidentally" sliced his hand while cooking dinner; nothing bad, but enough to need the first aid kit from the bathroom that Sam was in.

Sam was standing at the sink, sweats slung low on his hips and shirtless, when Dean barged through the bathroom door, saying something about Bobby needing some bandages and that Sammy'd better hurry it up –

The two boys froze, Sam facing Dean, his scarred back on full display in the bathroom mirror.

"What the –?!"

"Sammy?"

Startled, Sam looked at Dean in bewilderment, before suddenly realizing what had his brother so upset. He panicked, attempting to rush past his brother, only to be met by Bobby blocking the doorway, effectively preventing his escape.

"He needs to know, kid. This is eating you up. He needs to know."

For a brief moment, anger flared, causing Sam's eyes to flash dangerously.

"Needs to know what?" Dean asked.

At the timid tone in his brother's voice, masked behind anger and forced bravado, Sam deflated. He was tired of being strong, just tired. He realized that Dean needed to know, and he no longer felt strong enough to protect his brother from the truth. Bracing himself, Sam took a deep breath and turned to face his brother.

Only to be shocked by the heartbroken expression on Dean's face.

Sam caught a glimpse of his back in the mirror, and had to fight to get words past the lump that formed in his throat as he was forced to confront the physical manifestation of his deepest fears and weaknesses.

So, slowly, hesitantly, Sam began to talk. He told Dean about how, after Dean had been knocked out, the demon had taken the knife to Dean's arm just to torment Sam. Then, the demon had forced Sam to see what life would have been like had he never been born. He told him how he'd seen Dean grow up in a stable home with two loving parents and how Dean had been so happy. He talked about Dean's wife and kids, about the great things that he did. He talked about how their mom and dad had lived to see old age, to see their first batch of great-grandchildren.

Sam told Dean about how, after these "visions" for the first 24 hours, the demon had taken out a wickedly sharp knife and began to carve those hated words into his back. Never with the intent to kill, but always with the intent to scar.

"It's all my fault, Dean. Everything. If I'd never been born, Mom would still be alive and you would have had a happy life. The demon just put on the outside, everything I am on the inside."

"Sammy…" Dean began gently, not knowing what to say to ease his brother's fears, heartbroken that he'd had to go through that alone.

With a glance at Bobby, who met his gaze steadily before nodding and walking into the other room, Dean grabbed Sam gently by the arm, leading him upstairs to the room the two boys shared. Sitting Sam down on the bed, Dean took a seat beside him.

As he tried to find the words, Dean realized that now, while everything was still so fresh, nothing would convince Sam that none of this was his fault. Nothing would allow his little brother to believe that those words that had been viciously carved into his skin were lies. So, instead of a long speech, Dean simply rested his hand gently on his brother's back, covering the words, letting his continued presence comfort where words alone could not.