AN: Wow! So much interest in my little story! There are not words enough in any language of this world and the Potter-verse to express my thanks! I love you all, you're brilliant, wonderful people! :D I will try and keep up the standard of story writing you have come to expect from me, and I hope you continue to reward me with your little comments. :)

No man is rich enough to buy back his past. - Oscar Wilde

The trip to Hogsmeade was a cold and uneventful thing, all except Harry managing to dodge yet another one of Slughorn's party invitations. Sirius hadn't come with them, preferring to stay behind in the warmth of the common room, which, as they trudged back through the blustery sleet, Harry wished he had done.

Sirius sat in one of the comfy arm chairs and gazed into the fire, it was warm and he was glad he had chosen to stay behind, but he half wished he had gone with Harry, if only so he could be at his side rather than sitting alone and thinking, as ever, of their exploits in the Room of Requirement. He smiled softly to himself as he immersed himself in memories, he ignored the very obvious stares he was getting from the few girls on the other seats.

When Harry returned, later than Sirius had expected him, he jumped to his feet and ran over to greet him happily. But Harry looked less than happy and when he jerked his head towards the seats Sirius followed him and the four of them sat down. Harry explained what he had witnessed and how McGonagall had dismissed his idea that Malfoy had given Katie Bell the cursed necklace. Sirius sat in silence as Harry spoke and when he finished he gazed out the window thoughtfully.

"I just wish I had some proof, some idea of what he's up to!" Harry muttered darkly after a while.

"Harry, how many times do you have to be told? Malfoy wasn't even in Hogsmeade!" Hermione said with a sigh.

"Yeah, mate, he couldn't have been the one to give her the necklace." Ron agreed.

"I know it was him! I just wish I had proof..." Harry huffed as he sank lower in his seat with a dark frown on his face.

Sirius watched him, his eyes dark and heavily lidded so he resembled his cousin. He didn't join in their conversation when they began discussing who the necklace was intended for. When everyone went up to bed he didn't follow, Harry gave him a concerned glance. "Are you alright?" He asked.

"I'm fine, prongslet...go to bed, I'll be up later." Sirius smiled to try and ease his fear but Harry went to bed feeling cold and lonely. When Harry had gone up to the dorm Sirius stood and slipped out the portrait hole, he walked with a determined stride as he made his way to the seventh corridor using the secret passageways. When he stopped outside the painting of the Trolls learning Ballet he walked past it three times and when the doors opened he stepped inside.

"Damn it!"

The curse echoed loudly through the vaulted ceiling and Sirius made his way towards it, when he turned a corner he saw Malfoy sitting slumped against a cabinet with his fingers in his hair. Sirius moved towards him, each foot fall silent and Draco didn't even notice him until he was feet away. When he looked up he made a noise of shock and leapt to his feet, backing away with his wand in hand. "What do you want, Black?"

Sirius watched the wand calmly for a minute before smiling, a smile that would have suited a serpent. "I am here to reconsider your offer, Malfoy." He said softly, taking a step closer as the blond narrowed his eyes suspiciously.

"Why would you suddenly reconsider?"

Sirius shrugged, running a finger across a dusty broken sideboard. "No idea...boredom perhaps? Or perhaps I've decided that I'm enjoying being alive and whole far too much to be handed over to the Dark lord. Choose one..." He moved closer to Draco who still looked wary. "There is only one issue I have...I refuse to take the unbreakable vow."

"Then you will know nothing! I don't trust you."

"Of course, and that's a very sensible attitude to have. Trust is a weakness, it blinds you to betrayal. However, there are more ways than one to make a pact, Malfoy. Didn't Daddy ever teach you that Blood is stronger than any vow?" He lifted his palm and Draco's eyes widened in sudden comprehension. "Very good, not as stupid as you look are you?"

"I'm not...!"

Sirius cut him off. "Let's get this over with." He said sharply, eyes glittering beneath the light of the many candles which Draco had lit and placed on every available surface.

"It's Dark Magic this...are you sure...?"

Sirius gave him a sharp look. "I know what I'm doing. What do you take me for? Remember who it is you're speaking to, Malfoy." He removed a sharp silver pocket knife from his robes and flicked open the blade. "Blood Magic is Dark Magic...but it's strong. Come on, you know what to do."

Quickly Draco moved forward, pocketing his wand and placing a candle upon the surface of the nearest sideboard. "I don't just want you to swear you won't tell anyone..." He whispered hoarsely, his eyes avoiding Sirius'.

"Name it and I'll see what I can do." Sirius replied, the silver knife glittering like his eyes.

"I-I...I want..." Draco flushed and looked away, frowning.

"Ah, I see." Sirius blew hair from his eyes. "If it's to stop me from being sent to the Dark Lord then I guess you can take whatever you want." He said, voice rough as he lifted his hand and sliced the palm open. He barely even winced as crimson blood painted his white skin. He closed his fingers into a fist and held it above the candle flame, his eyes met Draco's who still looked shocked at what he was doing. "Say the words then." He muttered as his own blood ran in tiny rivulets down his knuckles and hissed as they burnt up in the orange flame.

"O-Ok." Draco swallowed and removed his wand, holding it above Sirius' hand. "Do you Sirius-..."

"Orion." Sirius muttered, frowning into the flame as he began concentrating with all his might.

"Do you S-Sirius Orion B-Black...swear to keep what I tell you here a secret?"

"I do." Sirius breathed, eyes narrowing even further as he whispered a chant in his mind.

The candle guttered, the flame briefly flaring as crimson as Sirius' blood. "D-Do you swear t-to help me to the best of your ability and follow any order I g-give you without q-question?"

Sirius licked his lips briefly. "I do."

"Then swear it."

"I swear."

When Sirius uttered the last two words the flame roared higher, it engulfed Sirius' hand but if he was in any pain he hid it. The flames went from red to bright, searing green before dying and the candle went out with a snake-like hiss. Sirius gasped and fell backwards, he looked at his hand, opening it to see the blood staining his palm and the black soot covering his knuckles. With a wince he licked the blood off and silently hoped he had been able to pull off his own secret spell...he had never done wandless magic before and he wasn't certain if it had worked. He swayed slightly as dizziness overcame him and he slumped against the cabinet, panting softly. Malfoy shook slightly as he gazed at the blood stained candle, then he blinked as if waking from a dream and looked at Sirius who gazed at him through a curtain of black hair. Draco smirked. "And now you have to do whatever I say..."

Sirius smiled and straightened himself out. "So it would seem. What will you have me do first?"

"Tonight?" Draco gazed thoughtfully at his new found companion for a moment before his smirk widened. "I want you to tell me what is between you and Potter."

Sirius sat down on a desk, he didn't feel a compulsion and he took that as a good sign. "Well, if you're asking that means you already know." He replied slowly.

"I suspect, that's entirely different from knowing. Now tell me."

Now that was an order, Sirius waited for a second and when he didn't feel anything he smiled inwardly, his counter spell had worked. "We've slept together." He said softly, eyes never wavering from Draco's. He knew that he had to speak some truths, because if he lied often Draco would be more likely to discover it.

"So, you sleep with other boys?"

"Occasionally, when the fancy takes me."

"I see..." Malfoy stepped closer. This was what Sirius had been dreading, but he held his ground as Draco ran a casual finger up his thigh slowly. "I want to..."

Sirius raised an eyebrow. "You want my body in exchange for my help. I got that already. Let's get this over with then, shall we." He lifted his hands and slipped his robes over his head, letting them fall into a crumpled heap on the floor. Draco watched him in fascination as Sirius began unbuttoning his shirt. Suddenly the Slytherin grabbed his Gryffindor tie and yanked on it hard, Sirius fell forward and off the table with a shocked gasp. Draco removed the tie and threw it to the floor where he set fire to it with a flick of his wand. "Red and Gold doesn't suit you, Black."

Sirius watched his tie smoulder. "Obviously not." He replied softly as Draco grabbed his hair tightly and yanked his head backwards.

"You're mine now, dog." He said with an evil smile.

Sirius returned it. "If you say so."

Through the whole encounter Sirius never made a sound, even when he was in pain. He simply closed his eyes and tried to think of other things. Draco had forced him onto his hands and knees so he felt glad that he didn't have to look into that face, the face that resembled Lucius. When it was over Draco left him there to tidy himself up before staggering to his feet and leaving the room feeling violated and used, but he kept telling himself the same thing over and over...

It was for Harry. It was because Harry needed to know the truth of what was happening. Everything was for Harry...What did his body, his pride and his own self-worth have against Harry's happiness? If he could use his body to manipulate Malfoy into giving away his plans then he could tell Harry what the blond was doing and make him happy, because he only wanted to see him smile. He never wanted Harry to stop smiling. He had decided, when Harry had told him he cared, that he would do anything for him...he would walk through the very flames of hell and worse if it meant that Harry would simply hold him at night.

When he reached the Dorms it was late, very late and so he washed very quickly and in cold water before sliding beneath the covers of Harry's bed and snuggling into his warmth. He smiled as he felt Harry murmur sleepily and wrap his arms around him. "G'night Harry." Sirius whispered contentedly.

When Harry had his next lesson with Dumbledore Sirius took the time to go meet Malfoy as they had arranged. He found the blond in the Room of Requirement, bending over inside the cabinet. When Sirius approached Draco turned and smiled. "You came, I didn't think you would."

"I swore." Sirius replied. "So, what is it you're doing?"

"Not yet, Black. I'll tell you when I'm nearer completing it." He said firmly. "For now I want you to just help me...I could use your magic."

"Ok. What do you want me to do?"

Harry returned to an almost empty common room, Ron and Hermione were the only ones up. He frowned as he searched for Sirius. "Where's...?"

Before he could complete his question the portrait hole opened and Sirius climbed through, one look at him told Harry something was wrong. He was pale and swaying slightly on his feet, his robes were torn slightly and when Harry drew closer he saw dark stains on them. Sirius smiled weakly. "Hi." He muttered as he stepped forward. Harry made to touch him but Sirius flinched away, holding out his hands. "Best not...I..." He sighed heavily. "I'm tired...I'm going to bed." He moved towards the stair case but Harry stopped him.

"What's wrong?" He asked.

"Nothing Harry...I'm sorry." He walked up the stairs without a backward glance, leaving Harry feeling confused and worried.

That night Harry lay awake listening to the gentle snores of his fellow dorm mates, he frowned up at the canopy of his bed as he remembered the state Sirius had been in, he had had an odd smell clinging to him, like something burning and something else...something that reminded him of their time in the Room of Requirement. He heard movement and he listened as feet moved across the stone floor and his bed curtains were drawn back, he turned to see Sirius' form, highlighted in silver moonlight. He moved over and Sirius slipped into his bed and snuggled beneath the blankets, he let out a small, contented sigh. "I can sleep when I'm with you." He whispered quietly as Harry wrapped an arm around him and buried his face into his long silky hair.

"Why can't you sleep?" Harry replied feeling Sirius shift in his arms as he rolled over to look at him.

"Nightmares." He said softly.

Harry nodded, pushing hair from Sirius' eyes and leaning towards him. They kissed slowly for a long time until they had to breathe, he felt Sirius push his body closer, his breathing becoming ragged. "Sirius?" Harry muttered against his lips.

"Just kiss me." Sirius replied, an odd bite to his voice that made Harry worry. "Kiss me and tell me you won't leave me...don't let me be alone."

"I promise, but what is this all-mmm..." He felt lips against his own, stifling all his questions until his mind was wiped blissfully blank. "Sirius..." Harry moaned as Sirius pressed himself closer, wrapping a leg around Harry and moving his hips slowly.

"Do you need me, Harry?" Sirius muttered, kissing Harry's throat, his sharp teeth nipping at the flesh lightly. "Tell me you need me and I'm yours...forever. I'll never leave your side."

"Siri, wha-nn..." Harry was finding concentration very difficult.

"Just say you need me...that you want me and I'll do anything for you." Sirius sounded desperate, his fingers rough as he slid his hands inside Harry's pyjama bottoms. "I'll throw myself off of the Astronomy Tower if you just said so. Please, Harry..."

"I..." Harry closed his eyes, losing his train of thought as skilled fingers made waves of pleasure sweep through him. Finally he sucked in a sharp breath and grabbed Sirius' wrist, halting his movement and forcing the other boy to look into his eyes. "What's wrong? Why did you come in tonight looking like hell?"

Sirius smiled, cocking his head to the side. "I want to bring you a gift...and make you happy. I can't say yet...but it'll be good, I promise."

"You're not yourself...if you're hurt or in danger or..."

"No...nothing like that. I-I just..." He sighed. "Never mind." He began drawing away but Harry caught him again, drawing him closer and pressing his lips to his forehead.

"I do need you Sirius."

Sirius let out a soft sigh and when he looked at Harry he was smiling, eyes sparkling in the moonlight. "That is all I wanted to hear. I'm yours Harry, forever. No matter what happens, know that I'll never betray you. I'll follow you forever."

Harry had time to briefly wander if that was a healthy thing in a relationship. He had always known how loyal Sirius was, in much the same way his canine alter-ego was, but hearing him just throw his heart at anyone willing to say they needed him was a little disturbing, did he really care so little about himself? He thought about all the stories he had heard about people who beat their pets and House-elves, treating them like dirt and yet they continued to remain loyal and devoted to the detriment of their own health. He frowned to himself, but all these thoughts were blown away when he felt Sirius move down beneath the duvet. "Sirius what are you...?" Harry stopped mid-sentence when he felt wet heat encase his erection. He groaned heavily, his fingers sliding into that soft silky hair as his eyes closed. "Sirius..." He whispered, trying to keep his voice down.

With Harry's words echoing in his head Sirius continued to seduce Malfoy's secrets from him. It was so easy it was almost laughable, Sirius simply had to smile and Malfoy would spill all his fears, all his worry and even the fact that it was he who had given Katie Bell the necklace, although he would refuse to answer who it had been intended for or who his informant outside Hogwarts was.

Time passed and Harry had the first Quidditch Match of the season drawing rapidly closer, he had little time to dwell on anything else, especially with his massive work load. The teachers expected them to all be using Non-verbal spells and the only lesson he was any good in was Potions, with the help of the book he had received from Slughorn and Sirius' encouragement. Hermione hated the Half-blood Princes book but Ron agreed that it was harmless, even with the fact that Harry had been learning the handwritten spells inside. Sirius had told him about Levicorpus and that it had had a boom in popularity in his time, he didn't recognise many of the other spells that Harry pointed out so they tried them out on Filch, Crabb and Goyle to rather amusing results.

One evening Harry was sat cursing his inability to do non-verbal spells. Sirius overheard him and he drew closer, watching Harry point his wand at a quill he was trying to levitate.

"You're not concentrating hard enough." Sirius muttered as he took a seat beside Harry, he drew his own wand and gave it a flick, the quill rose into the air and did a few circuites of the common room before coming to rest back on the table.

"How do you do that?" Harry exclaimed miserably.

"Easy when you get the hang of it, it's all in the way you concentrate..." Sirius smiled slowly. "I can teach you...help you practice if you want?"

"That would be brilliant." Harry muttered with a relieved sigh, Sirius' smile was ecstatic, like a puppy given a task to do.

"In exchange can you teach me to do a Patronus? I heard from Hermione you can produce a Corporeal Patronus?"

Harry nodded. "It's a stag, always a stag."

Sirius' smile was utterly beautiful. "I want to know how."

"Ok, we'll do that."

So, Sirius ended up teaching Harry non-verbal spells and Harry taught Sirius how to do a Patronus. They had fun sneaking off to the Room of Requirement for practice sessions and afterwards a quite bit of snogging in the gloom as the candles guttered in their holders. Sirius was passionate, a force of wild energy that grabbed Harry's heart and squeezed it so he had difficulty breathing, when Sirius was in his arms, touching him, kissing every part of him he could reach Harry could think of nothing else, even Malfoy and his activities were driven from his mind.

Sirius was a brilliant teacher and an even more brilliant student, he took to the charm easily, making it look as simple as a hovering charm. His patronus began as a silvery mist, as he concentrated upon one of the few Happy memories he had. Harry was pleased with his rapid progress, and it wasn't long before he produced his first, fully-formed patronus.

"It's got to be a significantly happy memory Sirius." Harry said softly from where he sat on a nearby chest.

Sirius scrunched his nose, making Harry want to kiss it for some bizarre reason. He pushed that aside and concentrated on watching Sirius try to work the charm. "Damn it all!" He muttered furiously as a stream of unformed, pale smoke drifted from his wand. "I can't do it!" He whinged.

Harry chuckled. "It's hard, isn't it?"

"Yes." Sirius sighed and ran fingers through his hair. "I'll try again." He closed his eyes and rifled through his memories, his first thought had been of ones of James and their briefly snatched privacy in closed off classrooms...then he saw, in his minds eye, a flash of emerald green eyes and a bright smile spread across his face. "Harry?" He muttered, still not opening his eyes.

"Mm?" Harry had a book on his knees, only half paying attention to Sirius as he read Advanced Potion Making.

"Tell me again."

"tell you what?" He looked up to see the light from the windows highlight Sirius' face, he was smiling.

"That you need me."

"What? Why?"

"Just do it."

"Alright...I need you Sirius Black." Harry whispered, smiling faintly.

That was all he wanted. Sirius raised his wand. "Expecto Patronum!" He said clearly and all of a sudden, bright white light filled the room, Harry blinked away the after image and when he fully opened his eyes he saw a great, hulking dog running across the room. "I did it!" Sirius exclaimed wildly, he turned to face Harry grinning.

"You did." Harry said, smiling back. "A dog...not all that surprising, is it?"

Sirius shook his head as he watched his Dog fade into glittering mist. "Thanks, you're a good teacher, you know that?" He reached Harry's seat in two quick strides. "Maybe I should call you professor." He smirked as Harry pushed him in the arm playfully.

"That's weird..." Harry replied. He smiled as Sirius leaned closer.

"Kiss me Harry." He whispered softly, and Harry smiled and did as he was asked.

Under Sirius' tutelage Harry found that he had an unrealised aptitude for silent spell work. Once he had done it once it was easier to do it again, and again, until he was pulling off non-verbal spells with an ease that shocked his teachers and made Hermione almost jealous. Ron and Hermione had no idea of Sirius' secret lessons with Harry, and they kept their rendezvous to themselves.

Hermione noticed how close Sirius and had become and it worried her more every day. Even with the cold way Ron was treating her on top of everything else, she simply did not like the way Sirius would disappear every night and once she had even sneaked the Marauders Map from Harry's bag to check for Sirius...and she couldn't find him anywhere. She resolved to keep checking whenever she could, and one day on the night before the Quidditch match between Slytherin and Gryffindor she saw his dot beside that of Draco Malfoy's, they disappeared soon after and with a snap everything clicked into place. Why was Sirius spending time with Malfoy in the Room of Requirement?