Sam was crossing the street when he saw him. Quickly, he hid behind some people passing by, and watched as the man looked around, to make sure he wasn't being followed, and entered a two-floor abandoned building nearby. Waiting for a few seconds to make sure that he wouldn't see he was being followed, Sam quickly made his way from behind the people to the door.

Seven months. It had been seven months of fake leads and dead ends, but he had finally found him.

Feeling his heart pound, Sam waited a few more seconds, just to make sure that he wasn't at the door anymore before opening it and going inside.

Seven months ago he and Dean had found a way to reverse what Metatron did, and together they hunted down and killed Gadreel, finally getting their revenge on Kevin's death. And they would have killed Metatron too, but Cas had been real clear when he said he'd deal with that.

Closing the door carefully, he could barely see anything. He squinted his eyes and saw what seemed to be a set of stairs. He could hear footsteps walking away and saw the shadow of the man. Sam held his breath.

Seven months ago, Dean said that he couldn't be with Sam if it meant they weren't gonna be brothers. "...I can't trust you" was what he answered.

The man however didn't seem to have seen him, as he kept going, the sound of his footsteps getting farther and farther. Sam let the breath he was holding go and started climbing the old wooden stairs, being extra careful not to make any noise.

Seven months ago, Dean left.

The stairs lead to the first floor of the building. He blinked a few times, trying to adjust his view to the new lighting of the room. Scanning it quickly, he saw a few old chairs by the open window and a torn carpet on the floor. He felt the cold noon wind against his skin and shivered. The man wasn't there.

The first few months after his brother left weren't easy. He'd sit alone with a bottle of beer, Dean's beer, drinking himself to sleep night after night, cursing himself for letting Dean go, but not sorry enough to call him back.

He turned around to climb the last set of the stairs until the second floor. Being as quiet as possible, he made his way to them and put his left feet on the step, and it creaked as he did so.

He'd wake up screaming at night, covered in sweat, from the worst nightmares. Dean being killed by vampires, Dean burning in the ceiling, Dean putting a gun through his mouth...

He froze, waiting for something to happen. Nothing did. Sam quickly reached for his jacket pocket, from where he got a flask of holly water.

When the booze on the bunker ended, he'd decided it was enough. Being sorry wouldn't bring Dean back and besides, although the angels were no longer a problem, Abaddon still was. Taking a good shower and shaving up, he started going through the books from the men of letters library, one after the other, trying to find a way to kill her.

Steering his shaky hands, Sam managed to open it. He put his other hand on the pocket of his jeans, where he felt the demon blade.

Many weeks later, he finally found a very interesting, black cover book. On the cover, with golden letters, it read: Hell Knights.

He paused for a second, considering on taking it but decided against it. With a deep breath, Sam started climbing the last set of stairs.

When he finally finished the book, he got up and his mind was racing. He had to find Dean before it was too late. The next thing he knew, Cas was standing right in front of him.

"Hello Sam"

There were no windows on this floor, and the very few lighting that entered it came from cracks on the roof, or some holes on the wooden floor. Sam instinctively started touching the nearest wall, and moving away from the stairs as quick and as softly as he could, since the floor creaked so badly it looked like it was gonna fall at any second.

Cas told him that he and Dean had been working together ever since he left, trying to track Abaddon down. He said Dean had killed her, with the help of the first blade and the mark of Cain. Sam felt a chill go down his spine.

Everything fell quiet when he leaned against the wall and Sam could only hear his heart pounding on his chest. Suddenly, a laugh cut through the air. "Hello Sam, it's been a long time"

Sam eyed Cas, begging him to tell him that Dean was ok. He knew he wasn't though, the words from the book clear in his mind.

Sam started looking around as he tried to find where the voice came from. It was no use. "yes it has" he agreed, walking alongside the wall, not bothering to hide the noise from the wooden floor as his eyes adjusted to the darkness. " Why don't you come out and say hi then?"

"I tried to stop him, but he wouldn't listen" Cas said, eyes full of sorrow. "I'm so sorry Sam" he lowered his gaze and Sam's heart shattered into a million pieces.

He heard footsteps walking closer to him and kept looking to all sides, trying to find where it came from. The demon laughed again. "You shouldn't have come here, Sam" he said. "I'll give you one chance. Walk away now, or die"

Cas pulled out a piece of paper from his trench coat "You'll find your brother here" he said, apologizing silently. Sam took it and accepted Cas' apology. "This isn't your fault" was all he said. Cas offered him a smile. "You know what you have to do" his eyes darkened again and Sam nodded, watching as Cas disappeared, this time for good.

Sam saw something moving on the opposite wall. He took a few steps back and leaned on the wall again, eyes never leaving that shadow. "You know I can't do that"
The demon sighed, seeming really disappointed. "Then you don't give me a choice" he answered.

Sam noticed that the floor right in front of him looked odd, as if there was a hole there and someone tried to cover it up a long time ago. The demon didn't seem to know about it, as he was moving closer, not bothering to look down. Suddenly Sam's mind flickered and he had an idea.

"You say it like you can actually do this" He said, moving towards the demon, that stopped walking.
"You think I can't?" He asked, on a mocking tone but defiance was clear in his voice.

"Yes. We both know you can't do this. You are not strong enough, you never were" The demon moved a few steps forward and Sam grinned. Just a few more...

" The me you knew is gone" the demon stated. "Killed by your selfishness" he spat the words like they were poison, as he pointed at Sam, who shook his head.

"No, we know that's not true" Sam said, walking even closer, almost on top of the hole. The demon too, moved closer.

"Oh really? Then what did it?" Anger clear in his voice. Sam just needed him to take one step ahead and it would be done.

"The fact that you are so scared of being alone you rather turn into a demon than try" That was it. The demon started running towards him and he stepped on the hole, as Sam threw the holly water on his face.

"AAARGH" the demon yelled, as the floor cracked and he fell down to the first floor. Sam quickly put the flask back into his coat and went down the stairs

The demon was completely bloody and his left leg was stuck under a big pile of broken wood. It saw Sam coming and tried to flee the body it was possessing, but Sam held his hand up, preventing it, his eyes momentarily going black.

"Drinking demon blood again, are we? And then they say I'm the monster" the demon laughed, but that turned into coughing and he spit blood on the floor.

"Just enough to keep a hell knight still" he replied, moving closer and pulling the demon knife out.

"If someone who has lost everything he loves the most uses the first blade to kill a hell knight, the person itself will turn into one, for its heart is as dark as the one of the thing it killed" Was what the book said.

He kneeled in front of the demon and his eyes softened. "I'm so sorry I wasn't there, Dean" he said, as he closed his eyes and put the knife through his brother's heart, watching as it flickered a few times and his lifeless body fell to the ground, completely still.