DISCLAIMER - It's none of it mine. JK Rowling's house and garden, I'm just visiting.

The lines in bold print are direct quotes from HP & The Half Blood Prince.

Thank you so much to all who have favourited and followed the story. I am honoured.

Learning to Trust Year 6

The Great Hall at Hogwarts School of Witchcraft and Wizardry was alight with thousands of floating candles, the long tables filling with students, hurrying to the annual start of term feast.

One of them, a bespectacled boy, now starting his sixth year, took his place at the Gryffindor table between his two best friends.

Harry Potter felt unusually sombre amid the happy chatter of the returning students.

On the other side of the room, he caught sight of the pale and pinched features of Draco Malfoy and anger curled deep in his abdomen. He itched to wipe the haughty sneer from that arrogant face. He thought about how good it would feel to get even with Malfoy, his stinking father, Lucius, his murdering aunt, Bellatrix Lestrange.

Harry tore his gaze away and fought to rein in his temper. These days it rose easily and he needed to keep it under control. He wanted very badly to make them pay for what they did, for what they took from him.

"Who's that geezer?" Harry's attention was distracted by Ron's question.

He looked around as his friend indicated the middle aged, balding, slightly portly man who was sitting to the left of the dark haired, stern faced Professor Severus Snape, who was Harry's guardian.

"That is Professor Slughorn, the new Potions teacher," the answer came from Harry's other side, where Hermione Granger was also watching the teacher's table.

The changes to the staffing arrangements were filtering through the student grapevine with the usual speed. The habitual vacancy arose each year at Hogwarts for a Defence Against the Dark Arts teacher. It was common knowledge that Snape wanted the job but until now, it had always eluded him.

This year, Harry's guardian would have his wish and stepping into his shoes as Potions Master was the genial Horace Slughorn, by special request of the Headmaster.

Only Harry, Ron, Hermione and Snape himself knew this last part. As far as the rest of the school was concerned, this perplexing alteration was the surprise of the year and speculation surrounding it accounted for much of the animated conversation unfurling around Harry.

In the days that followed, the sixth year Gryffindors who were taking Potions certainly regarded the changes to the staff as a welcome development. Pleasant and easy going, Horace Slughorn drained the dungeons of the intimidating atmosphere that had radiated from the very walls when Professor Snape held dominion there.

Even Harry found that Potions had somehow become less of the mountain he could not climb. Mind you, the accidental acquisition of a second hand Potions book had at least as much to do with that as Professor Slughorn's kindly teaching approach.

On his very first lesson Harry had won the vial of 'Liquid Luck' Slughorn had put up as a reward for the most successful student. It wasn't that he had suddenly tapped into a knack for brewing potions, the book, which had belonged to someone who called themselves 'The Half Blood Prince' was filled with minute but exact instructions, written in a scrawling penmanship. The additions were insightful, helpful and unlocked the secrets of potions in a way Harry could never have figured out alone.

"Harry, it's cheating! You would never have gotten away with that when Professor Snape was in charge here!" Hermione admonished but Ron shot her a dismissive glare.'

"Ignore her Harry. Our Hermione doesn't like coming second!" Ron said.

Privately, Harry held that Hermione was right but he wouldn't admit it. It did feel good to excel as Hermione did so often at her subjects and Dumbledore had instructed him to court Slughorn's favour. Surely he wouldn't find fault with the means Harry had found to carry out that command.

Yet Harry kept the book secret from his guardian. He knew that Hermione was also right in pointing out that he would not approve of Harry's secret weapon.

When the Professor asked how Potions were going, Harry was vague and assured him that all was well. Severus knew only too well that Harry's talents at Potion making were limited, it would arouse his suspicion if Harry suddenly revealed his new found position at the top of the class.

"It's kinder, really," Ron argued one evening after yet another star performance in the dungeons from Harry .

"Might make Professor Snape feel like he's sort of failed if he was to discover that another teacher can teach Harry so much more," he went on.

Hermione rolled her eyes. The idea that Snape could be made to feel insecure so easily was like suggesting the Hogwarts stone could turn to marshmallows.

"But another teacher isn't helping Harry. It's that book! And what do we know about it or the Half Blood Prince? That could be anybody Ron!" Hermione was not one to give up an argument lightly.

Harry was idly thumbing through the dog eared pages of the book as his friends squabbled. He'd heard it all before and though he did feel a little guilty about the book, he simply could not give it back. He found himself turning to it when he had nothing else to do, intrigued by the mysterious 'Half Blood Prince' who had inscribed the book as his property.

Harry had no idea who he was but his neat script filled the pages, improving the instructions within, deciphering the most complicated spells brilliantly. Harry could not explain it but he felt he knew the Prince, whoever he was.

Ginny Weasley looked up from her armchair close to the fire in the common room.

She had a curious expression on her face. Curious and concerned. She stood and crossed the room, coming to stand in front of Harry, lifting the book from his hands and flicking through the pages, her face intent.

"You don't know how this book came to be in the dungeons?" she looked at Harry, frowning slightly.

Defensively he reached out and took the book back, closing it with a snap. He felt annoyance stir. Of course Hermione couldn't stop blabbing on about the book where anyone could hear! Who was she to lecture him like she was a teacher here anyway and who was Ginny to be looking at him as though he had done something wrong?

He rose to his feet. "I know that it works! That's good enough for me!" he snapped.

Ginny met his angry eyes with an even stare.

"You should know better than to trust a book full of magic you can't explain. Don't you remember what almost happened to me, Harry?"

Her words had more effect than any of Hermione's scolding and Harry felt instantly guilty and more than a little doubtful. Tom Riddle's diary had almost cost Ginny her life.

"This is different," was all he could think to say before stuffing the book into his bag and turning away from them all to climb to his dorm.

If the identity of the Half Blood Prince perplexed Harry, the increasingly agitated behaviour of Draco Malfoy was even more puzzling. Anything but friends, the enmity between he and Malfoy had escalated since returning to Howarts.

The sight of the exchange on a deserted Hogwarts corridor between Draco and the Professor caused his curiosity to flare from interested to hooked.

Snape was towering over Malfoy, head bent, talking to him intently, his hand pressed against the wall beside the blond head. Malfoy was arguing, a rare occurrence, not least because Snape was Draco's favourite teacher.

Something about the scene disturbed Harry and he felt an unfamiliar emotion souring in his stomach. It made him feel unaccountably disjointed to see Severus and Draco communicate like that. Malfoy comfortable enough to debate his position, something no other student would have dared attempt before Snape, the most fearsome teacher this school had seen these many years.

The Professor so serious and clearly concerned. Why should he care what Malfoy was saying? And why wasn't he sentencing the self important Malfoy to a month's worth of detentions for answering him back? If Harry had dared to cheek him up like that, his guardian would be far less tolerant.

When Snape turned and stalked away, black robes snapping in his wake, Harry watched Malfoy enter a bathroom, and he could not resist following.

He would never have been able to explain why he did. He was moving before he even thought about it but seeing his guardian talk to Malfoy as though he mattered, as though looking out for him, it made Harry's head swim and his chest tighten.

As the door closed behind Harry, he realised two things at once. Firstly, he was alone with Draco in the bathroom and secondly, the other boy had clearly been crying.

Although Malfoy's back was turned, Harry heard the quiet sobs as the pale youth leaned on his arms over a hand basin, obviously trying to get his composure back.

Before he had quite managed it, he sensed the presence of another and turned, his eyes narrowing coldly as they alighted on Harry.

"Potter! What are you sneaking around for? Seeking a quiet spot to mourn your poor dead criminal of a godfather?"

The taunt worked perhaps because not so deep down, Harry wanted it to. His wand was in his hand before he knew it. The hex discharged on a surge of green light very suddenly and though Malfoy was upset, he was ready. He deflected it and had sent his own curse flying even as the hand basin behind him shattered.

Water sprayed around the room but neither boy cared. Harry took aim and it felt so good, so liberating to finally release the hatred he felt towards this boy.

"Sectumsempra!"

The curse came to Harry as though he was reading the inked words on the yellowed page of his Potions book. It was like the Prince was with him, engaging in the fight against Malfoy.

Nothing could have prepared him for what happened next. Light issued from his wand, found its mark. Malfoy's face registered the pain, contorted and then he was falling, blood pouring from gaping wounds on his chest to turn the water on the bathroom floor crimson.

Harry stood a second, transfixed with horror. Then he raced to the stricken boy, to where Malfoy was lying at an odd and uncomfortable angle, his limbs twisted beneath him. The pallor of his skin had whitened to near transparency. Still blood pumped from him, drenching his robes, pooling around him.

Harry picked up his wand, sent the alarm to his guardian, the one person he could think of to help him now.

Severus had not gone far from the second storey corridor where he had left Draco when he felt he vibration of his own wand. Immediately he drew it, let it guide him, doubling back on his own footsteps, worry for his ward making his feet swift.

The scene that greeted him in the wrecked bathroom defied belief. Harry was hunched over the prone figure of Draco Malfoy and several, angry weals had torn the skin of the fallen boy's chest, so he was bleeding profusely. Unconscious and weakening, Malfoy had clearly been a victim of a dark spell, one so vicious and repugnant that Severus refused at first to believe it had been cast here. Cast by the only other occupant of the room, his ward.

His black eyes found Harry's. A deep frown knitted his brows and Severus knew at once what had happened. Afterall, it was his own spell. He should recognise it when he saw it.

Harry had never seen such a look on his guardian's face before. It was more than anger, worse than shock. It was abhorrence.

The Professor did not speak. He bent over Draco and ran his wand over the gaping wounds, stemming the scarlet flow. Then he gathered the boy's ailing form in his arms and made for the door.

There, he turned around and gave Harry a look that was colder than the grave.

"You, Potter… wait here for me."

It did not occur to Harry for a second to disobey. He stood as water dripped, the only sound in the eerie silence of the empty room.

He drew in one tremulous breath after the other, waiting, frozen in time.

He may have killed another human being. Had he? His eyelids burned as though the image of Draco bleeding was scorched onto the insides of them.

He had trusted the Prince and he hadn't thought what could happen. He had imagined some discomforting hex but death? No, surely not. Please, please no. Too late he realised that Hermione had been right. Ginny had warned him. Why hadn't he listened?

Ten minutes later, the door opened and the Professor walked through it. Harry's eyes flew to the darker, shielded face of his guardian. He desperately looked for the hope he so wanted.

"Sir, how is he?" he asked at last, finding no succour in the stony expression of the older man.

"He will live,"

Severus spat the three words, flicking his wand at the bathroom door to lock it as it closed behind him.

He was assailed by so many thoughts at once that his clever mind was momentarily overwhelmed.

The boy was terrified, that he saw at once.

Good, another part of himself responded. Harry had damn near killed another student, wielded dark magic with precision and without the slightest thought for the consequences. Who was this boy that could seek to hurt another so easily?

He was his ward, his, Severus Snape, whose own black desires had so often guided him. Had some of that corruption eroded Harry's innate kindness? Was this what six years with him had achieved, to teach him to damage someone else without preamble?

By Merlin no!

Severus moved, swift as a serpent to cover the distance separating him from Harry. The silvery form of a pigtailed girl rose shimmering between boy and man.

"Out!" Severus roared at the ghost and Moaning Myrtle instantly disappeared down a nearby toilet with a frightened cry.

He grasped the boy's arm in a fierce hold, turning him so that Harry almost lost his footing on the slippery floor.

He shoved him so that he was facing the wall, Harry raised his arms, placing his palms against the cold tiles to hold himself upright.

"Do I need to tell you that using dark magic is not something I will tolerate from you, Mr. Potter?" his guardian ground out.

Harry found himself pinned against the bathroom wall, as Snape's hand was pressed between his shoulder blades, holding him firmly. He could not answer through the tears that clogged his throat. So he shook his head.

He knew what was going to happen. He deserved it. Whatever Severus did to him now he had earned.

"Wait! No, Sir, please, not this way!"

Still, Harry could not stop the plea leaving his mouth. He knew what Snape was going to do but his guardian had never carried out this punishment without putting Harry across his knee.

Being spanked and held away like this was more than Harry could take.

Snape understood at once. The boy was not resisting the punishment but he was asking for contact with the man issuing it.

For a second, he was tempted to ignore the cry and bring his hand down as though he had not heard or cared.

Then, he remembered the fright in Harry's eyes every time he thought of Vernon Dursley. He remembered the small boy who had once trembled in his presence, expecting a world of pain from the stranger sworn to protect him.

Severus once again reached forward and grasped the boy's arm. This time, he led him to the row of sinks, where he lifted his foot to rest a polished shoe against a raised pipe.

He bent the boy forward to lie over his upturned knee. Harry grasped a fistful of his robes and buried his face in them, a childish gesture that made Severus' heart feel heavy and unaccountably sad.

In silence, he delivered the spanking at a blistering pace. For the duration, Harry kept his eyes closed, his guardian's cloak pressed against his face, so that he was surrounded by the familiar and soothing scent of spice and dried herbs.

Harry let the tears come and when at last, the Professor rubbed soft circles on his back, signalling the end of the spanking, he lay crying, unable to think of a way out of the nightmare he had crafted to life.

Severus lifted him to his shoulder, holding him tightly.

"I never meant it!" Harry cried brokenly.

"I know," Severus' voice was matter of fact.

He held the child a little longer, unwilling to deny him the comfort he craved.

Then, he put his hands on Harry's shoulders, lifted him away. Thunderous anger still clouded his guardian's features and Harry struggled to face it.

Just then, the doorknob rattled.

"Potter? Professor Snape?" Professor McGonagall's voice sounded though the heavy oak.

Snape rose his arm, his wand drawn. Harry barely heard the incantation and the door opened, by magic.

The Head of Gryffindor entered the shattered bathroom, a harried look on her face as her eyes shot to the forbidding form of her colleague.

The Professor moved automatically so that Harry was shielded behind his back. The boy was distraught, he had not gathered himself after being spanked and Severus wished to afford him a little privacy before he had to face another.

Confronted by the emotionally charged situation in the water and blood splattered room in front of her, Professor McGonagall faltered slightly.

"Severus, Professor Dumbledore needs to speak with Mr. Potter. Whenever you are ready," she said, lowering her eyes and withdrawing.

Again, silence descended on the room, broken only by the sounds of dripping water and the boy's hitching sobs.

Severus did not look around.

"The book. Bring it to me. Now."

His voice was quiet, soft even but deadly. Harry swiped at the tears that were drying on his face and stared in surprise at his guardian's rigid back.

"Do not think to deny it. If you lie to me, the consequences will make that spanking seem but a happy memory by comparison," Snape's tone was steely.

"How did you know?"

Harry marvelled at how the Professor always tapped into his secrets.

"Not now, Harry. Do as I told you. Borrow a copy of the Potions manual from one of your friends. Put it in your bag. Bring me the other. Quickly now," Severus nodded at the door and this time, Harry obeyed without another word.

He hastened to the Common Room where he found Ron pouring over Transfiguration homework.

The red haired boy's expression swiftly turned from surprise to concern when he saw the blood on Harry's clothes.

"Harry! What happened? Are you alright?" he shot to his feet.

"I'm fine Ron but I need to borrow your Potions book and fast," Harry said, reaching for his own bag and dragging the Prince's copy from it.

"I'll explain later. Thanks, mate," Harry took the book from Ron's outstretched hand, thrust it into his bag and once more hurried from the tower, back to the bathroom where the Professor stood waiting.

Severus barely looked at the book as Harry gave it to him. He pocketed it in the folds of his robes and at last, he met the green eyes of his young ward.

"Harry, listen to me now. As you might expect, the Headmaster will have some questions for you. But leave any lengthy explanations to me," he said.

And before Harry could respond, he had opened the door and was striding along the corridor to the golden griffon that stood at the entrance the stairs leading to Dumbledore's office.

"Severus. Harry, come in."

The door opened upon Snape's knock and Professor Dumbledore's greeting was polite as always.

"Gentlemen, have a seat,"

The Headmaster indicated the soft chairs by his fireplace. Snape inclined his head.

"Thank you, Headmaster but there will be no need. As you aware, one of the students in my house is in the hospital wing and Mr. Potter and I have yet to have a discussion about that," Severus replied, casting an unsympathetic look at Harry.

In fact, Severus wanted to spare Harry the trial of sitting. He had never marked the boy, he had always been careful that if he spanked him, the discomfort never exceeded the superficial and this time had been no different.

But Harry had just been punished and in truth, the palm of Snape's own hand still smarted from the delivery of it.

And his ward was shaken, as was Snape at the events that played out earlier. He was no doubt preparing himself to be expelled and he was watching Snape guardedly.

Evidently, he understood the discussion Severus had spoken of would involve further discipline. The legacy of Vernon Dudley haunted the boy like a wicked ghost.

"Ah yes. Mr Malfoy. How is he Severus?" the Headmaster rose a bushy eyebrow, his keen blue eyes kind.

"Madame Pomfey has given him a treatment with Dittany. He is resting comfortably and there is unlikely to be any scarring," Snape replied.

Dumbledore nodded and said nothing more for long seconds. Then, his eyes alighted on Harry, serious behind the glinting half moon spectacles.

"It is sometimes too easy to let our darkest natures have a free hand, is it not, Harry?" he said gravely.

"I'm sorry, Professor. I did not intend to hurt Mal.. Draco. Not like that," Harry said.

"I believe you but alas, harm was done. As is the inevitable outcome when temper controls us, not the other way around," the Headmaster said, his voice melancholy.

"Professor, Potter's remorse is sincere, I have no doubt. The matter is not at an end as I think we are all aware but I would like to handle this as his guardian. I am sure Harry's Head of House will also have something to add," Snape said.

"I agree, Severus. But Harry, I feel that from now on, you must apply yourself to the task I mentioned to you at the start of term. Retrieving Professor Slughorn's memory must be your priority," Dumbledore gave Harry a piercing look.

"Believe me when I say that working towards a goal is a much better tonic for what you might be feeling than the temporary relief provided by lashing out at others."

Harry's face showed only surprise.

"You mean I'm not going to be expelled?" he asked.

Dumbledore shook his head.

"Sanctions will be issued, Harry and I have full confidence that your guardian will act appropriately. But you will not be removed from the school," Dumbledore's words made Harry's knees turn to jelly as relief coursed through him.

"Thank you, Sir," he said quietly, knowing he had been handed more of a reprieve than he deserved..

"You may go, Harry. But remember, absolute focus from now on. I trust that you will not disappoint me," Dumbledore nodded to his door and Harry turned to leave.

"Headmaster, a word?" Snape lingered and Dumbledore nodded. Severus accompanied Harry to the door, laid a hand on his shoulder.

"You will return to our quarters, not the Gryffindor tower. I will be there shortly," he instructed.

"Yes, Sir," Harry took his leave, his sense of reprieve not quite eliminating his apprehension.

What if Snape no longer wished to be his guardian? Staying at Hogwarts would be poor compensation for losing the closest thing to a family he had ever known.

In the absence of the boy, Snape withdrew the tattered Potions book and tossed it onto Dumbledore's desk.

"The source of this little problem. Written in my own hand," he said contemptuously.

Dumbledore looked at him knowingly.

"So the fault is yours?"

"Who else could have taken a good boy, brave and kind and turned him into an angry, destruction seeking inflictor of pain?" Severus tone was savage.

"Loss and grief are making Harry angry, Severus. And I think that few are better placed than you to know what that can do to someone. Or to help him find a better way," the Headmaster's face was settled into a look of certainty.

"He used dark magic and he learned it from me," Severus' face was a bleak as his tone.

"Harry had no idea what that spell could do. He picked a fight with his rival. He sought for a way to get the upper hand. Not untypical of teenage boys, Severus. When he saw what he had done, what did he do?"

Dumbledore waited.

"He sent an alert to me," Severus said slowly.

"Yes. He reached out to you, the first person to enter his mind when he was in trouble. He sought help for the other boy and you said it yourself, his remorse was sincere and swift," Dumbledore said.

A deep frown gouged Snape's grim features. He hadn't thought in those terms.

He was still deep in thought as he took the stairs to his quarters almost two at a time some moments later.

When he opened the door, a fire was burning low in the grate and the boy was nowhere in sight. Severus knew Harry would be in his room, watching the door and waiting for a beating he had never stopped fearing.

He breathed in a slow, steadying breath, walked to a antique sideboard and poured himself a shot of fire whiskey from the bottle that rested on it.

When Harry heard Severus enter, he waited in his room but when his guardian did not seek him out, Harry went in search of the older wizard.

The Professor had his back to him and he was sipping a glass of amber liquid. Harry had never seen Snape drink alcohol before and he stood, immobile, waiting for the storm to crash on his head, wondering if he should flee or stand and take it, afterall, he had done plenty to deserve whatever was coming.

"Sectumsempra,"

Severus turned and set eyes of flint upon the boy.

Harry nodded, taken aback that yet again, Severus knew the answer without even asking the question.

"Yes." There was no point in denying it and Harry had given up asking how Snape knew these things.

"The spell is mine. I was in my sixth year here when I invented it. It was some time later before I tried it out. The man was not quite so lucky as Draco Malfoy. He lost an arm and an eye. Then again, perhaps I cast it with somewhat more malice in my intent than you," Severus took another sip from the tumbler in his hand.

Harry stared, he never expected this admission.

"You are the Half Blood Prince?" he frowned, puzzled but yet it made sense. He had felt all along that he somehow knew the Prince even though that seemed impossible.

A brief incline of the head signalled his guardian's assent.

"But how?" Harry was intrigued.

"My mother's maiden name was Prince. She was a witch, my father a muggle," Severus said.

Harry sank into a chair near the fire, forgetting the fading discomfort of the spanking he had received.

"Much like your uncle, he was quick with his fists, slow to see anything but the wrongs he felt the world dealt him," Severus went on.

"Unlike Dursely, he harboured a crippling fondness for this," Severus lifted his whiskey glass.

"It gave him the courage to spew his frustrations at his weakness, at those he blamed and resented,"

"When I realised that I could do magic, I had the one thing he craved. Power. He hated me for it. After I came here as a student, I never saw him again."

Severus set the glass down and walked towards the boy, who was watching him, wide eyed and silent.

"I am not going to hit you. I never have and I never will. I have been where you are, Harry, sitting, waiting for the next blow. I know how fear tastes and if I could take it from you, I would lift my wand now and do it. But there is no spell for that. There is only time. And I will give you all of that you need to trust that there will be no beatings here," Severus said.

"I saw your face. Back in the bathroom. You wanted to do it. And I don't blame you," Harry said in a small voice.

"You have been spanked. That is the extent I will touch you for this or any other infraction." Severus' eyes were steady.

"I am angry, Harry. At you and at myself. I can't exactly flog us both."

The words had the desired effect of making the boy smile a little. He looked up and met his guardian's eyes, his face pale but open.

"You have been good to me, always, from the first day I came to live with you. I haven't made it easy. I am bad, Severus. I am just like him, Voldemort."

Harry dropped his head, falling silent and Snape's face darkened as a frown drew his brows together. He crossed his arms over his chest and glared at the boy.

"What on earth would make you say such a thing? Are you trying to make me lose the last ounce of my patience with you, Harry?" Snape was a wrathful figure, scowling malignly as he regarded his ward.

"I hurt Malfoy. I could have killed him. And I got away with it! Why? Because I am the Chosen One. Dumbledore needs me. How many times did Tom Riddle show his true colours when he was here and walk away? He was clever enough to get a pass," Harry stood up and looked up at his guardian and Severus realised these thoughts had been a long time forming before they came to the boy's tongue.

So he said nothing. And waited for the rest of it.

"He is an orphan. So am I. He is a parsel mouth. So am I. The sorting hat wanted to put me in Slytherin. Did you know that? I felt myself attack Arthur Weasley a year ago. I revelled in it as Voldemort did. And now Malfoy is in the hospital wing. How long before I kill someone?"

Tears shone behind the rounded spectacles. Severus maintained his silence. He slowly unfolded his arms, reached out and placed his hands on the boy's narrow shoulders.

He dropped his head low enough so his eyes were level with Harry's.

"I have spent the last hour wracking my brains trying to figure out when it was exactly that my darker side influenced you to act in a way not natural to you," Severus said, his voice barely above a whisper.

"And you have spent quite some time, it seems trying to figure out why you and the Dark Lord are so alike. Do you know what that means?" Snape rose a brow.

Harry shook his head.

"It means, Mr. Potter that neither you nor I have shown much good sense," Harry's eyes widened in surprise.

"In the first instance you have not gotten away with the incident with Mr. Malfoy. The tenderness you betray when you sit down is a reminder of that. There will be further sanctions and we will talk of them later," Severus said.

"The similarities between you and the Dark Lord are not entirely coincidental. In part, they come from the fact that when he tried to kill you, he imparted something of himself. There is a connection between you that is complicated," the man let the words sink in.

"For my part, I have been letting the ghosts of my own past haunt my present with you," he pressed on.

"You are not the same as the Dark Lord. You are not my father and you are not me," Severus said.

He turned the boy and stood him to face the mirror that hung above the fireplace.

"What you are feeling is remorse, Harry. And it is something that the Dark Lord could never feel, not now, not when he walked these halls as Tom Riddle. You are not in Slytherin and why? You made a choice, am I correct?"

Harry looked at his reflection and nodded.

"It is the choices we make that define us. Today, you chose to hit out at a boy you do not like. Faced with the awful consequences of that action, you chose to help him. To take responsibility for what you did. Not the choices a killer in the forming would make, young man."

Gratitude flowed into Harry like sunlight as he heard the words, felt the truth they contained. His shoulders slumped.

"It's not only the ability to do magic that makes you a more powerful man than your father, Severus," Harry looked into the reflected gaze of the sombre man behind him.

"You are a better dad than he ever was,"

Harry turned and met the Professor's astonished eyes.

"And you didn't have to be. You told me so yourself once. You made a choice too. And I owe you everything because of it."

Severus truly could not think of a single thing to say. And he was glad of that as he did not think he would be able to speak anyway.

He had spent lifetime learning to control his emotions. He did not loosen that command lightly but the simple honesty in the boy's eyes had his throat tightening.

So he turned away, presented Harry with his back. Swallowed. Closed his eyes. Willed the pain in his chest to ease.

"Everything," he repeated the word.

Glanced back at the boy.

"Then you have paid the debt in full, Harry."