A/N. This story is loosely based on one of the letters in A Letter Instead by LilyBolt. Thanks for letting me use your chapter as inspiration! And thanks to all who have read, followed and favorited my work, you're all amazing! Oh, and shameless plug, I definitely recommend you read some of LilyBolt's work, it is fantastic! And as always, I do not own Supernatural, sole rights go to Kripke and Co.

Redemption

He's never seen a Hellhound before, though he has heard the snarls and baying of the beasts on more occasions than he would care to remember. He'd cringed at the sound of claws on hardwood flooring, the whines of the creatures in the distance, and the feel of hot breath as the beast tore past him, intent on capturing its prey. He had witnessed as one of the invisible beasts had attacked Jo before his eyes, and worse still, had mauled his brother while Sam had helplessly looked on. Initially the fact that the beasts were not visible to the naked eye had made them more sinister, more horrifically terrifying than if they had been seen by anyone other than one with a one way ticket to Hell. It was the sheer unknown which was so frightening: where is it? What does it look like? How close is it to ripping my insides to shreds?

But now, wearing those ridiculous glasses and ready for the kill, Sam realizes that the physical form of the Hellhound is more terrifying than he could have ever imagined. This was what Dean had seen before the creature had slowly, agonizingly mauled him to death? This mangy, slimy creature, eyes red as red hot coal, fangs protruding from its cavernous mouth? God, how horrific it must be to have this vile creature be the last thing on Earth one would see before being drug to Hell.

Sam shudders, scans the surrounding darkness for any sign of his brother, or the demon beast which roamed the property. And as he searches, adrenaline pumping through his veins, Sam clearly recalls that night in New Harmony, when his brother had for the first time come face to face with a Hellhound. The outcome had not been in the Winchester's favour. Sam had watched, horrified and sickened, as the foul creature tore at his chest, reducing his insides to ribbons. He had witnessed as Dean thrashed and twisted on the floor, held down by some invisible force, blood spurting from all directions as claws tore through his clothes and into flesh. He had heard the agonized screams turn to low murmurs as the life slowly drained from his body, eyes glossing over with each passing second. He had held the lifeless body, cradling Dean in his arms as hot tears slid from his closed eyelids and plopped gently on his brother's face….

No. He can't go through that again. He has already watched his brother die, helpless to stop it from happening. He sure as fuck isn't going to let that happen again. A grim determination sets through Sam as he makes his way in the dark, ever on the lookout for one of Crowley's pets. And as he hears the howl of one of the beasts in the distance, another memory flashes through his mind.

"You did it." Sam watches, confusion and dread on his face as Lilith lies before him, dead.

"I mean, it was a little touch-and-go there for a while, but…you did it."

"What? What – what did I do?" A look of fear spreads across Sam's face as the finality of the last few minutes begins to take effect. He has just saved the world…right?

"You opened the door. And now he's free at last. He's free at last!"

A sinking feeling creeps in the pit of Sam's stomach as the reality of what has just happened starts to sink in. But he's still in denial. "No, no no no….."

Sam snaps back to reality, trying to push back any thoughts of that horrible night when he had broken the final seal. When he had betrayed his own brother by listening to a demon. A fucking demon for Christ's sake! Hell, in the past few years, Sam has done nothing but let his brother down. A mental tally of his past transgressions flash before him, a blatant reminder of his fucked up life: trusting Ruby, his messed up addiction to demon blood, freeing Lucifer from the Cage. He had caused the goddamned apocalypse! But the worst of it all, the real kicker, was the fact that he had betrayed Dean, the one who had raised him, taught him to hunt, drive a car, ride a bike. The man who had saved his ass on more occasions than possible, who had sacrificed his own soul to bring him back from the dead. Fuck, it was his fault that the Hellhounds had killed him in the first place.

"You've done everything for me," Sam mutters, feeling his grip on the knife's hilt loosening slightly. Well, this was his chance to save Dean for a change. To save the man who had never seen the light at the end of the tunnel, who had put his own head on the chopping block without hesitation if it meant saving Sammy, fulfilling his brotherly duty to protect him at all costs. Hell, the man was suicidal: the only reason he would want to live would be to keep his younger brother safe. Well, if putting my ass on the line keeps Dean from going for the kamikaze missions, then bring it.

And Sam admits to himself that there is a third reason why he wants to kill this creature of darkness: to atone for his sins, to wash himself of the curse which has brought to his family since infancy. For as horrible as his actions had been in the past, his infection with demon blood as a baby had triggered the series of events leading to his downfall. If somehow killing this Hellhound, taking on these supposed Demon Trials could set things right, to somehow cleanse him from his transgressions, then so be it.

The sounds of howling are closer, and Sam once more regains his grip on his weapon. To his right he can hear the heavy footfalls of someone running, and he realizes that once again Dean could become a Hellhound's chew toy. No. He is not going to let that happen again. Trying to push back the intense fear, Sam rushes in the direction of his brother's footsteps, the snarling of the demonic canine. Not this time, he tells himself, closing in on the distance between himself and his brother. That's a promise. He runs, heart pumping, adrenaline rushing through his veins, eyes peeled for his prey. And then he sees it. Dean is on his back, the Hellhound tearing into his side, vicious canines eager to tear into flesh.

"No! Stop! STOP IT!"

Lilith smiles vindictively as the Hellhound attacks, his brother crying in agony.

"NO!"

No. Act fast. As if somehow propelled by his memory, Sam is on the attack. The creature is on top of him in a flash, its face inches from Sam's, and he can feel the heat of its breath upon his cheek. He can faintly hear Dean cry out for him, but it's too late now. He has to do it. He has to finish what he has started. With a feeling of anger and intense satisfaction, he thrusts the blade in the mutt's belly, its dark blood soon covering Sam from head to toe. A feeling of both exhaustion and relief overwhelms him, and as Dean watches, open mouthed, Sam pushes aside the dead Hellhound.

He's alive. He's still alive. Thank God Dean's alive…

For a moment, Dean watches him, a look of grateful relief fighting with frustration and…was that anger? Of course, Dean's pissed because I put myself in harm's way. Typical over protective, recklessly suicidal older brother. Well, you know what, Dean? Tough shit. 'Cause I've let you down in more ways than you could possibly imagine. And I'm not going to do that again.

Sam looks at Dean, who for a moment looks like he just might kill Sam himself. But the feelings of relief overwhelm him and he limps to where his brother is laying, still covered in the creature's black blood, and pulls him in for a hug. Sam feels his emotions threaten to overpower him, and feels the tears well from beneath his closed lids. But by the time Dean pulls away, Sam has regained his composure, gently pats his brother on his good shoulder.

"Well, looks like it's my turn to save your ass for a change."