Disclaimer:  (I have too much time on my hands)

I do not even dream to own

The rights to Harry Potter.

J.K Rowling runs that show –

Last I checked I was not her.

Not doing this for eminence,

Sure not getting paid.

Just want to see poor Severus

Finally get laid.

~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~

CHAPTER 1: REUNION

A light summer rain fell over the grounds of Hogwarts and on the weary traveller who was walking slowly up the driveway towards to front doors of the castle. A trunk floated lazily behind the cloaked individual. The castle was strangely silent – the summer holidays had begun, and though most of the staff had remained behind due to the growing darkness within the wizarding community, there was still an air of emptiness about the place. The traveller paused to look up at the imposing façade, softened by rain, before continuing through the front doors.

The hood was drawn back to reveal a young witch in her mid-twenties who proceeded to shake the rain off her cloak. Pulling her wand from her sleeve, she pointed it at her gently bobbing trunk and murmured a spell. The large chest sank to the floor with a muffled thud. The woman slipped her wand back into her sleeve and looked around the deserted Entrance Hall. Mildly confused, she walked briskly to the closed doors of the Great Hall and pulled one open.

The sight that greeted the woman both comforted and concerned her. To see the long empty tables with the House banners hanging over them only gave her a reminder of a possible future should the war drag on – a virtually empty school, educating not enough children to fill even one of the tables. Yet, the sight of the full staff table, whose occupants had now stopped talking to look up at her inquisitively, gave her hope. These men and women, who had been larger than life in her childhood, seemed to retain their same power. The young witch walked along the side of the Hall and up to the dais at the front. Dumbledore stood and smiled gently down at the traveller.

"Miss Staunton," he said, "we are very pleased to have you here."

Rosaline bowed her head and looked up at the Headmaster, her young face serious. "I am pleased to be here – I was quite flattered when I received your letter, and I'm more than willing to provide you with whatever assistance you require."

"Thank you, my dear," the old wizard said softly, "your strength and skill will be of inestimable value here. But for now, please, sit and have some lunch. You have had a long trip."

Rosaline smiled gratefully and slide into an empty chair between a woman she did not know and the one remaining empty seat, at the end of the table. The puzzled looks from most of the professors simply confirmed her suspicion that Dumbledore had not informed the staff of the reason for her presence at Hogwarts. Which meant that he didn't know either. He wouldn't be pleased. Rosaline sighed. She nibbled at her food, eating very little – a habit she had long since lost the will to break – and instead spent most of her time glancing over to the seat beside her, half-afraid and half-hopeful that he'd suddenly appear there.

The staff members began to slowly leave the table, having finished their meals, till only Rosaline, Dumbledore and McGonagall remained; the latter two were engaged in deep conversation.

Not wanting to disturb her old professors, the young woman silently stood and slipped from the room. Her trunk was sitting where she had left it – apparently the house elves had no idea where it was meant to be either. As she stood looking at it, deep in thought, McGonagall hurried out of the Great Hall.

"There you are child, I was wondering where you were heading off to, seeing as we have yet to show you to your quarters," the old witch said with a chuckle.

Rosaline smiled and gestured to her waiting trunk. "I was about to go hunt down some house elves had you not arrived when you did, Professor."

The older woman clucked her tongue and smiled with uncharacteristic warmth. "Come now Rosaline, there's certainly no need for formality. Though you were a student in my house for 7 years, you're certainly not anymore. Please, call me Minerva."

Rosaline flushed with pleasure and flashed McGonagall the most genuine smile she had given since she arrived. Before she could respond, the older woman had levitated her trunk and was guiding it down the hallway. Rosaline jogged to catch up and listened as McGonagall continued speaking.

"Now then, we have quarters arranged for you, as well as a small laboratory prepared to your specifications. I was quite certain you'd not want to be in the dungeons, so we've put you in the South Tower. Not as high as the Astronomy Tower, but you'll have a lovely view of the lake nonetheless."

The two women spoke all the way to Rosaline's new chambers, covering almost every subject except the one Rosaline had expected and dreaded. The stairs of the tower conquered, McGonagall stopped before a large, imposing door, in the center of which was the sculpted head of a dragon. It blinked at the women lazily as the older witch slowly lowered Rosaline's trunk to the floor. She gave the dragon's snout a sharp tap with her now free wand, and the door swung open.

McGonagall smiled at Rosaline, but her eyes showed sadness.

"Take as much time as you need to settle in, meals are a very informal affair over the summer – usually there're no more than three or four of us here at a time." A look of pain crossed her face, but McGonagall quickly covered it and continued, her voice lower now. "I also want to express my condolences, dear…about your parents…"

Rosaline shook her head and put up a hand to silence the other woman. "It's alright Prof…Minerva. I'll see you at dinner tonight. I really just want to have a nice long bath and lie down for a while."

McGonagall nodded slowly and tried to smile. "Alright," she said, and turned to go, only to pause again.

"It's very good to see you again, Rosaline," she said softly, then disappeared down the stairs.

Rosaline watched her go, then levitated her trunk and guided it through the door which closed silently behind her.

~*~

Rosaline sat in her bedroom in front of the vanity, brushing out her long hair.

"You look tired, dear," the mirror chirped, "perhaps a little lie down before supper?"

Rosaline ignored the chatter and put down her brush. She stood up and looked at the large canopy bed for a moment, clearly weighing up her possibilities. Shaking her head, she turned from the bed and headed down the spiral staircase into her small library instead.

The afternoon sun streamed through the bay windows, resting on one of the two comfortable armchairs and a small reading table. Ignoring the bookcases full of volumes, Rosaline headed into the parlour which constituted the other half of this floor of the tower. She went briskly through the door of her chambers and down the winding stairway which led to the rest of the castle.

Striding purposefully through the halls of Hogwarts, Rosaline continued her descent until she reached the dungeons. They were chill, even in the warmth of early June. She idly raised her arm and trailed her fingertips along the damp stones of the walls, the same way a young girl would. Slowly making her way towards the Potions classroom, Rosaline wondered if it has changed in the past 7 years. Somehow, she doubted it.

Despite her dallying, the young woman eventually found herself standing before that same, imposing door. Rosaline glared at it definitely, refusing to be intimidated.

'I'm 24 years old,' she told herself, 'I can handle this man, the same way I can handle any other misfortune the fates throw my way. I've come this far, it'd be foolish to turn back.'

There was nothing to do but proceed, so Rosaline raised her hand and rapped loudly on the door.

~*~

Snape looked up at the door in irritation. His colleagues should know better than to disturb him while he was working. He turned his attention back to the relatively complex potion he was currently brewing, ignoring whoever might be knocking. They could be eaten by a rampaging manticore for all he cared.

Forgetting the interruption, Snape continued to add ingredients meticulously. He almost dropped the small bottle of beetle wings when the pounding on his door returned, twice as hard. With a snarl, he leapt to his feet and strode angrily to the door.

Flinging it open, fully prepared to inflict a scathing insult on whomever it was who had dared disturb him, Snape almost toppled backwards in surprise.

Rosaline stood, stationary, her eyes on him. Analytical, even when surprised, Snape noticed that her eyes were harder and colder than they had been years ago, when she was still a girl. She was also a little slimmer and a little paler than he remembered, but most noticeable was the bitterness in her face, the cynicism of one who has seen the worst the world has to offer.

'Of course she's bitter you fool,' his inner voice hissed, 'her parents were both tortured and murdered by Death Eaters last year.'

Snape gathered his composure about him like a fog and looked down his long nose at Rosaline.

"What are you doing here?" he purred dangerously. Without responding, the woman swept past him and into the classroom. Snape stood, dumbfounded, before his anger kicked in.

He spun and advanced on Rosaline, who foolishly had her back to him. She neither turned nor flinched as drew up against her, invading her personal space.

"Trying your hand at stoicism, Miss Staunton?" he breathed into her ear, slightly stooped so as to be at the right level to do so, "it does not suit you."

Rosaline spun suddenly, and Snape found himself nose to nose with the young woman, giving him a far better chance to study her eyes. The vitality, the spark was still there, but it was dulled, hidden behind bitterness and scorn for the world. He did not shy away from this change as most people would. Snape chose simply to probe, curious to see how deep the diamond-hardness went.

Rosaline broke first and allowed her gaze to slide to the floor submissively, but she did not move.

"Were you there?" she whispered, so softly Snape's already impressive hearing was hard-pressed to catch the question. "Were you a part of it?"

He shook his head and murmured a denial, his black eyes still staring at her intently. She shivered, and for a moment, she looked young and scared – very much like the girl he had taught a harsh lesson to on the lawn over seven years ago. This illusion disappeared in an instant as Rosaline dropped the impassive mask back over her features. She raised her eyes back to his and they were chips of green ice again.

"But you knew. You knew, and you didn't tell them. Didn't warn them about the trap, did you?" Rosaline's voice slowly rose in volume as she spoke, from a whisper to a pseudo-yell. She broke off and choked back a moan and pressed her hand tightly against her mouth to stifle the sobs that threatened to rise out of her throat.

Snape gently placed his hands on her shoulders, mildly surprised when she did not shrug them off violently.

"Rosaline," he murmured, "I did not know. If I had…"

With a cry, she pushed away from the tall man violently and spun to catch herself against a worktable. The two figures stood motionless and silent, Rosaline's quivering shoulders and back the only indication she was in any form of pain.

Long minutes passed before she straightened herself and turned. Her face was pale and drawn but not tear-stained, nor did her eyes show any indication of crying. Snape watched Rosaline carefully, unsure of how to treat this new incarnation of the girl whose vitality and bravery he once found captivating. This woman bore a striking resemblance to that girl, but without the eagerness, the animation and the lightness which had been indispensable parts of the latter.

Without warning, Rosaline strode past the Potions Master and out of his classroom.

Severus Snape did not move for a long time.

~*~

A handful of long June days passed, and Rosaline began to settle into life at Hogwarts. She missed her family manor in Ireland, and the small comfort she gained from knowing that though her parents were dead, she could visit their graves whenever she chose.

Dumbledore had still not made the staff of Hogwarts privy to the reasons for her presence there, which suited Rosaline. She had no misconceptions of Snape's reaction when he learned that she was to be working with him – and not solely in a teaching capacity.

She was to be a secret weapon of sorts. One to be kept from both the Ministry and Voldemort's forces. Over the 7 years since she had left Hogwarts, she had studied fiercely, her passion for her chosen field of work growing exponentially as the months stretched to years. She immersed herself in her study of potions, and became a Potions Master within a year. Two years later, still only 21, she became a senior member of the R&D division of the Ministry. She was happy with her life, and felt no rush to "settle down" as her mother called it. Even as rumours of Voldemort's existence began to circulate, Rosaline did not once think her parents would come to any harm. Both seasoned and talented Aurors, the young woman still half believed her mother and father to be infallible. In the arrogance of youth, she assumed there would be plenty of time to marry and give her mother grandchildren to fuss over.

Her world had been shattered when, in May of 1996, only 18 days after her 23rd birthday, her home had been invaded by a squad of Death Eaters. Rosaline had left shortly after the 7th, citing the need to get back to work. Her father had understood with his characteristic patience, while her mother had, as usual, fussed.

She could still remember them clearly, standing side by side at the front door of the manor just before she Apparated to Dublin to catch her Portkey, her father's arm wrapped protectively around her mother's shoulders.

That had been the last time she'd seen them. She'd sent the perfunctory owl once she'd arrived at her flat in Diagon Alley, just to tell them she was safe, how the trip was, and so forth. After that, her work had taken precedence. When she was summoned from her laboratory and told what had happened by a very sad looking senior Auror, Rosaline did not believe her. She returned to her laboratory and continued working till she was forcibly removed from her workbench and sent back to her flat.

It took her days to finally accept what had happened. After that…darkness. Those few months were a blur of black mourning robes, legal issues to slog through, matters to close, and bottles of Ogden's Old Firewhiskey. Rosaline lost herself, lost the girl she was, and once she managed to drag herself out from the pit of despair and alcohol she had fallen into, she was irreversibly changed.

Strangely, in this dark time she found her thoughts drifting to the curmudgeonly Potions Master of Hogwarts. That last night with him on the lawn, what he had told her then, played through her mind with alarming clarity – Rosaline thought she had long since forgotten his words.

"Though you are no longer technically a child, you are still innocent and naïve. You have much to learn of the world, Miss Staunton. Perhaps once you have existed in it as an adult, you will understand the consequences of this interlude, and understand…"

But Rosaline didn't understand. She became obsessed with discovering what he had meant. It gave her an outlet, something to concentrate her energies on other than grief. She continued her work for the Ministry, requesting the opportunity to work in the private lab in her family home. Her appeal was granted, and Rosaline found herself home again, but it, like it's now sole inhabitant, was changed.

Without her parents, the manor seemed an empty shell, much the same way Rosaline viewed herself. She eventually gave up on her attempts to decipher Snape's puzzling words, but was left painfully aware that what she once was in his eyes – the innocent and naïve child – existed no longer. Though she thought of him less, she found that every so often she would have strange dreams, images of black silk against pale skin haunting her sleep. Oddly enough, these dreams came to her whenever she had been working with rosemary or lemon balm.

A slow year passed for Rosaline, and she somehow managed to appear whole again, despite her 'maturing'. There was a hardness to her now, a chill in her demeanour which had never existed before. She pulled away from the few remaining friends she had and immersed herself completely in her work. A lonely existence stretched ahead of her, with little hope.

Then, one warm May afternoon, shortly after her uncelebrated 24th birthday, an owl arrived from Hogwarts. The letter from Dumbledore had an underlying urgency. Rosaline responded immediately and was on her way to the school as June began.

'And here I am,' she thought, staring out the window of her library. She was to pose as Snape's teaching assistant, simply another one of Dumbledore's collection of misfits and broken toys. Her real job still involved working with Snape, but in a more practical sense.

They had both been creating experimental potions – ones to aid Aurors in the capture or destruction of Death Eaters, to counter the effects of the Three Unforgivable Curses, and a medley of healing draughts.

But now, thanks to information collected by Snape, they were to combine their skills and attempt to create a potion which would specifically weaken Voldemort. Killing him was too much to hope for at this stage – the Order of the Phoenix was content to set their sights lower.

And through what was most likely her salvation from a cloistered, cold life of research – what she had dreaded most as a girl – Rosaline was finally able to understand Snape's mystifying words on that night 7 years ago. He was a spy, and though when she had been thrown into his life, when Voldemort was still believed to be vanquished, Snape had never given up his self-inflicted sentry duty.

She understood now.

Rosaline sighed and ran a hand through her still-unruly dark hair.