A/N: Hi Readers! This is just a small oneshot that came to me when I was reading the Half Blood Prince this morning. It kinda answers the question "Why was Horace Slughorn so reluctant to return to Hogwarts?" in more detail than I think was shown in the film/book, and there's also a lot of Dumbledore angst. As I always say, R&R please and read some of my other stories too! (most of them are K+ rated)

Warning: Although my bio says that I try not to go over a K rating this story is rated T because of implied Dumbledore/Slughorn. It isn't sexually related and is portrayed as wrong so please don't flame. Don't like, then don't read.

Disclaimer: My name is not J. , and I don't own any of the films or anything else related to Harry Potter, just this story.

"Is it true Horace? What everyone's been saying?"

Albus Percival Wulfric Brian Dumbledore, newly appointed Headmaster of Hogwarts School of Witchcraft and Wizardry, was sitting in his office beside his friend and employee Horace Slughorn. Before Dumbledore had become Headmaster the two of them had often liked to find a quiet and private place where they could banter about odd things and the like, for Dumbledore knew no other person that he could truly reveal himself to. Horace was someone who understood him and comforted him. Even now, if another member of staff such as Minerva McGonagall had burst in they would have probably mistaken this meeting for one of those times. But it wasn't.

"It hasn't been confirmed yet, Albus. All we know for sure is that the boy's father and paternal grandparents were found dead this morning by Muggle authorities. The Minister of Magic suspects that the Killing Curse was used, but apart from that…"

"It was Tom. I just know."

There was a moments silence between them, as both tried to fight the realisation sinking deep inside their hearts. It was Slughorn that decided to break the silence. "He's just a boy."

"You know as well as I do that Tom Riddle was never just some ordinary boy, Horace." His friend snapped bitterly, "He was one of your favourite students if I recall."

Slughorn looked sharply as if he had just struck him. "None of us could ever have known what he was destined to become. He charmed all of us Albus, even you…" He looked towards the floor, eyeing the Headmaster with disdain, "…the greatest wizard ever to have lived."

The Potions master looked up to find that Dumbledore had turned away from him, and to his horror tears began to fall from the old man's cheeks. He stood up and ran to his friend, embracing him and holding him closely as he howled in sadness and pain, letting him cry into his shoulders and waiting for him to respond. Eventually, he had calmed himself down and Horace let him fall backwards into his chair, and sat down beside him. The Professor began to speak.

"Albus… you know I didn't mean… any of that…"

Dumbledore smiled at him sadly, "Horace, you were right. I was a fool; an arrogant, proud fool!" The Headmaster suddenly thumped the table in front of him in anger and walked away from Slughorn, onto the balcony that came off from his office. "I should have done something, tried to stop him, to change him, anything…" He spoke softly as his friend appeared beside him, "The day I met him, I knew there was something different about him, something wrong… He spoke Parseltounge, for God's sake! Found it amusing to torture those unfortunate enough to cross him! No, I just put it all down to abuse, said that it would grow out of him within time." Dumbledore left his friend's side and began to pace across the balcony, his voice increasing louder by the minute, and continued, "Finding out that he was Slytherin's only heir didn't bother me. When that girl was killed in his fifth year, I let Armado Dippet blame it on a giant spider instead of trying to convince him that the Chamber of Secrets actually existed, because I myself refused to believe that Tom had summoned a basilisk to murder an innocent student…"

"I tried to get through to him, Horace, ever since he joined the school. But I thought he had changed. I was wrong."

Dumbledore bowed to his friend in respect and was just about to leave when he felt a hand grasp his shoulder. He turned to see Horace Slughorn staring at him with a look of sadness, but Albus could see that there was something else there too…guilt? "We all make mistakes, Albus" Horace muttered quietly, "Yet I fear my mistake is a lot greater than yours."

"Horace, have you not been listening? I ignored all the signs, I was…"

"I told Riddle about Horcruxes."

Dumbledore froze in shock and quickly averted his eyes, for fear of showing his disappointment. He had known that Slughorn had a weakness when it came to students and that at one point he had been strongly infatuated with Tom, but this… He found himself falling onto the handrails of the balcony in fear, and he looked back into his friend's eyes, begging to find some sign that he was lying. He was not.

"He came to me one evening. He seemed so innocent, and I didn't think there would be any harm in telling him." Horace began to weep silently, "He had his claws stuck so deep in me, flattering me with gifts and his words, like nothing anyone had ever said to me… I fear that he still does. Even as I speak with you I can feel his pull on me, as if he has the power to watch my every move. I cannot stay here. I have to leave Hogwarts." Slughorn strode off the balcony and into the office, grabbing his coat off his chair as he did so. Albus Dumbledore tried to reason with him.

"Horace, you don't have to do that. I can fight him like I did with Grindelwald, he's not that powerful yet."

"Dumbledore, he knows how to split his soul. He's probably read up all sorts of dark magic during his time here, and you're not as young as you were." Slughorn looked up, his eyes filled with hurt, "Besides, all you'd be able to see would be that boy you met at the orphanage 15 years ago."

He turned to leave the office, but Dumbledore got in his way. Their eyes met for a few seconds, and Horace could see the fear in Albus' eyes. "Horace Please…" he heard his friend choke. Slughorn saw the look in his eyes change from fear to want before he suddenly leaned forward and kissed him passionately. Albus gasped as he felt his friend's lips touch his, as he had wanted them to do for years now, ever since he had met him. They let themselves fall into their dreams for one brief moment, before Slughorn roughly pushed away from the Headmaster, leaving him standing there, his eyes full of confusion and then hurt. "Horace" he pleaded as Slughorn turned his back onto him and walked back onto the balcony.

"No Albus." He said coldly, and Disapparated.