When Harry Potter was four years old, Dudley Dursley demanded a sibling. A sister to be precise. Petunia and Vernon immediately fell in love with the idea of a daughter to spoil as much as their perfect son and headed off to the orphanage, Dudley in tow. And while Dudley got a new sister that day, Harry got a cousin that didn't treat him like shit.

Then in one of life's great ironies, shortly after your sixth birthday (which was the day before Harry's) you proved to be just as much of a 'freak' as your cousin when Dudley wouldn't stop picking on Harry. Your hands fisted at your sides and your brother found himself suddenly twenty feet away as you screamed at him to stop.

Of course, your new family refused to believe that you had been the cause and blamed poor Harry even when you told them it was you. When one too many unexplained things occurred when he wasn't around, they were forced to admit the truth. You, their baby girl, their sissy, were a 'freak'. When your so-called parents tried to treat you with the same level of love and affection they showed their nephew, Dudley forbade it. You were still his sissy even if you had caught Harry's freakishness. And wasn't that a fantastic theory? Harry was to blame for it all. As such, it only made sense that he pay the price for your freakishness.

It was no surprise then that by the time the two of you received your Hogwarts' letters that Harry hated you almost as much as the rest of your family. All in all, it made life rather lonely. Even when you came to Hogwarts, Harry immediately became part of the trio while you remained a loner. Then in your second year Luna Lovegood joined you in Ravenclaw and the two of you became instant friends.

At the beginning of your fourth year, Harry had been particularly nasty to you one afternoon. His hatred of the fact you'd spent most of your summer with the Lovegoods' seeping into his sharp words. As usual, you said nothing in response, simply standing there and taking his abuse. Suddenly, Harry's tirade cut off and a heavy hand fell on your shoulder.

"Twenty-five points from Gryffindor for verbally attacking another student, Potter." Professor Snape's rumbling deep voice eased some of the tension from your shoulders. Potions was your favorite class and you'd always liked the prickly professor for some reason. "Fifteen more for your language."

Harry glared and his mouth twisted as he prepared to argue, but Hermione tugging on his arm stopped him. Giving you one last nasty look, he turned and stomped away.

You swallowed the lump in your throat. "Thank you, professor." Your voice was soft, barely there as you tried desperately not to give into the threatening tears.

He made a sound of agreement before squeezing your shoulder gently. "Come with me, Ms. Dursley." He left his hand on your shoulder and steered you to his office in the dungeons. Once you'd made it inside, he led you to chair. "Sit. Are you comfortable with me shutting the door?"

You nodded your head. "Of course, professor." Not only did you trust the man implicitly, there were wards on the castle that immediately alerted the headmaster if a student should be attacked. Not that they seemed to do much good half the time, you admitted to yourself.

As he took the seat behind his desk, a tea service appeared and he poured you a cup before passing it over for you to prepare it to your taste. "Now, explain to me, Ms. Dursley, where this animosity between you and Harry Potter comes from."

That was the first of many meetings you would have with Severus Snape over the years. At first they were infrequent, once a month or so but by the time you returned to Hogwarts for your fifth year, it had become a weekly occurrence. Now you were three weeks into your final year and you were avoiding Severus like the plague. He was bound to notice, of course he was. He wasn't an idiot. But you had no idea how to go about having the conversation you needed to have with him.

While your seventeenth birthday had brought the expected magical maturity, it had also brought an unexpected creature inheritance. It had taken the rest of the summer for you to learn how to hide your ears and tail. Just as you thought everything was going to be fine, school resumed and it took exactly one half of a potions class to realize Severus Snape was your mate. Merlin. Sometimes you swore Magic hated you.

He should have come to the same conclusion when you did, if not before, but he'd said nothing to you about it. Maybe he wanted to ignore it, to pretend you weren't his mate. The thought hurt more than you thought it would.

You were cleaning up at the end of another potions lab when the professor passed by your desk. "Remain after class, Ms. Dursley."

You sucked in a breath and his heady scent swamped your senses. "Of course, professor."

Once the room emptied, Severus headed toward his office as he motioned you to follow. He didn't spare a glance in your direction. You sat in your usual chair and watched him prepare your tea the way you liked it. It was only after he leaned back in his seat with his own cup that his gaze met yours.

"Now, why are you avoiding me?" That smooth, sultry voice wrapped around you offering a comfort you didn't realize you needed.

You coughed a little on your drink and shook your head. Your cheeks heated as you denied his words. "I'm not."

He snorted. "Bullocks."

You crinkled your nose in distaste at the expression which made him smile ever so briefly. You sighed and sat your cup on the edge of his desk. "Do you really not know?"

His brows lifted at that. It was obvious he had no idea what you were referring to.

Your hands tangled together in your lap as you cleared your throat. You tore your gaze from him as you revealed your cat ears and tail. He came to stand beside you in the long stretch of silence that followed. "May I?" he asked quietly.

You nodded in agreement though you weren't entirely sure what he was asking permission for. That question was answered when his long fingers ran over the tips of your ears. They twitched beneath his touch. In a swirl of robes, he was back in his seat and you risked a glance at him. There was nothing but curiosity in his gaze. You bit your lip, drawing his gaze before he met your eyes again.

"Neko?"

"Shadow neko," you corrected.

He sucked in a breath in surprise. "Those are incredibly rare."

The corner of your lips lifted slightly at the awed tone. "I'm aware."

"What did Gringotts say?"

You leaned back in your seat and crossed your legs. This wasn't a discussion you wished to have with him. With anyone. Eventually, yes, but not when you were still coming to grips with it yourself. "Those tests are incredibly expensive. Well beyond the ten pounds in my pocket." The only way you had even been able to attend Hogwarts had been through their fund for indigent students.

His brow furrowed. "Why didn't you say? I would have paid for it. You need only ask."

Your cheeks heated again. "You know why." You were too proud to beg or even ask for help from a friend. It was a trait shared with the professor so you knew he'd understand.

"Very well," he agreed after a moment. "None of this explains why you are avoiding me, however."

You took a deep breath and dug up the little Gryffindor bravado you kept buried under your Ravenclaw smarts. "You're my mate."

If you hadn't been watching when you said the words you would have missed the brief flash of warm hope in his eyes. As fast as it came, it was gone to be replaced with cold hatred. Your chest grew tight and your stomach sank.

"Get out." His voice was so soft you barely heard it.

Fear flooded through you. He couldn't reject you. He just couldn't. You had anticipated him being unhappy. After all, you were student even if you were of age. And you were just you. There was nothing special about you. But the two of you had the greatest conversations. You got along well. You had thought – hoped – he liked you at least a portion of how much you liked him.

"Sever—"

"It's professor, Ms. Dursley. Now, get out."

You were frozen in your shock. "But, professor, I don't understand. Please." You hated the plea in your voice, the tremor in your hands.

"I had a mate and lost her many years ago the same night your idiot cousin somehow survived." He gave you a moment to process his words. It couldn't be true. He was your mate. You knew he was. Your head spun in confusion.

He fisted his hands on the desk and pushed himself to his feet to scowl down at you. "I thought better of you than to resort to such cruelty. I am unsure what you hoped to gain other than your own entertainment at my pain at being reminded. I feel no connection to you. No bond. At this moment I can't even say I like you. In fact, I wouldn't be your mate for all the galleons in Gringotts after this little stunt."

With that, he swept from the room, obviously too impatient to wait for you to leave. You sucked breaths into your tight chest hoping for some relief. Hot tears flowed down your cheeks and dripped into your lap as a sob wracked your body. You stumbled to your feet and into a shadowy corner of his office. With a thought you found yourself in your room where you immediately collapsed on the bed and cried yourself to sleep.

***

In the days that followed you became another specter in a castle full of them. Your quiet figure would move from class to class, keeping yourself pressed against the walls as you went doing your best to stay out of the way. Luna stayed your constant companion but you didn't seem to be talking to her either. You sat at the table during meals but pushed the food around on the plate, eating the minimum required to keep you functioning.

After a week you no longer bothered to conceal your ears and tail. It took so much energy. So much more than you could spare. Your scent also changed to the sweet scent of an unmated submissive to signal to alphas you were available. Not that you would pick any of them. Snape may be certain you weren't his mate, but he was yours. Your neko wanted no one else. Would accept no one else.

You were on your way to class when you found yourself surrounded by five Gryffindors. Two of them were alphas but you couldn't place any of them. You didn't care enough to. One of the alphas stepped closer while his friends hemmed you in. "Hello, little neko."

You curled in on yourself even more than usual. Your shoulders hunched in an effort to make you seem smaller than you already were and your arms wrapped around your waist. "Hello. Please move. I'll be late to class."

"Oh, you've got plenty of time. Don't be like that. We just want to get to know you." He kept his voice sweet, coaxing but the vibes you picked up from him were anything but nice.

When you ignored him and tried to push past, he grabbed one of your wrists and tugged you into him. You pushed against him, but his grip was too firm. "Let go."

Before he could respond, a deep voice interrupted. "I believe she told you to release her." Severus Snape to the rescue.

The boy immediately released you and took a step back, his hands up in a gesture of faux innocence.

"Twenty points from Gryffindor for harassing another student. A submissive at that. Each." They groaned but dare not say anything as Snape would only make it worse. "And a week's detention with Filch. Two for you, Thomas. Go."

The boys scattered as you wrapped your arms back around yourself. You kept your back turned to the professor, unable to look at him.

"You must know that as much as the use of magic in the halls is frowned upon, you are allowed to defend yourself," he finally said.

You gave a nod though you still didn't face him. "Yes, sir."

"Next time I expect you to do so."

"Yes, sir." You hurried off then, needing to get to your class and away from the man that already haunted your every moment.

In your potions class that afternoon, you kept your head down and focused on your brewing. The potion, while complex, was one you had brewed before. Professor Snape moved through the students, checking their work and lecturing when needed. He came to stand by your desk and you did your best to ignore him until he'd been there for several minutes without saying anything. "Can I help you, sir?"

"What. Is. This?" he bit out as he tugged back the sleeve of your robe to reveal the dark bruising around your wrist from your earlier encounter.

Your face heated as you covered the mark. "It's from before. It's fine."

"It is not fine." He swept away from you in a twirl of his robes. "Detention tonight, Ms. Dursley. Immediately after supper."

"Yes, sir."

***

At the end of the class, Severus' gaze followed you as you left the room. He was still furious that you'd been injured to the point of bruising. His reaction was out of proportion to the injury. He knew that but couldn't seem to do anything about it. It was taking everything in him to not track down Dean Thomas and teach him a lesson about how to treat a submissive. Especially one as precious as you.

The potions master groaned and dropped his head into his hands. He hadn't lied when he told you that he felt no bond with you. There was no connection there. There couldn't be. While some creatures may get the opportunity for another mate should the first die, Vampires weren't one of them. One life mate for the longest lived species of them all. Oh, the irony. Of course, once the bond was complete, one mate wouldn't outlive the other anyway, their lives and souls intertwined completely.

He had been less than truthful about his feelings for you, however. He'd always had a soft spot for you from the moment you first walked into his class. As you grew and changed, so did his feelings for you. For a time, he'd thought about pursuing you after you left the school but then you'd turned out to have an inheritance which meant you had a mate. He wouldn't rob you of that. He couldn't be that selfish. Not with you.

When you'd told him that he was your mate, he'd had a brief moment of happiness before he remembered that was a possibility that was taken from him many years ago. You weren't the first student that thought it would be amusing to tell the dungeon bat he was their mate. Ha, isn't that funny? But you...Merlin, that had hurt more than he thought possible. At the very least, he'd imagined the two of you were friends. But friends weren't cruel to one another. The didn't play with one another's feelings.

He sighed and cast a quick tempus realizing he'd been brooding longer than he intended. Realizing the meal was nearly over, Severus requested a light dinner from a house elf. Once he'd finished eating and started brewing a batch of pepper-up potions for the infirmary, he realized you were late.

Leaving the potion under a stasis spell, he started for Ravenclaw tower. He was interrupted by the arrival of Dumbledore's patronus summoning him for a meeting. He clenched his jaw in irritation but headed for the old man's office. He arrived to find the other three head of houses but no headmaster. Severus rolled his eyes. Albus would be late for his own meeting.

He shifted his gaze to the diminutive Charms master. "Filius, one of your eagles failed to show for detention."

Flitwick frowned. "Who?"

Severus crossed his arms and leaned against the wall. He didn't wish for you to be in trouble with your head of house, but he was concerned for your wellbeing after the incidents of the day. "Dursley."

"Ah, just who we're all here to discuss. Thank you for bringing her up, Severus," Albus said as he swept into the room and took his seat. "Lemon drop?" he offered and everyone shook their heads.

The Ravenclaw head of house bounced in his seat a little. "What about Ms. Dursley?"

Albus hummed. "Ms. Dursley has left Hogwarts for the time being. Hopefully she will return before winter break."

There was a stunned silence until McGonagall broke it. "Left? What do you mean she left? It's her NEWTs year, Albus."

He folded his hands together on his desk and peered over the top of his glasses. "I am aware, Minerva. However, it was brought to my attention by a concerned classmate that Ms. Dursley's mate has rejected her. As she is a submissive neko, you are all aware of the issues this can cause. Myself and Ms. Pomfrey felt it in her best interest for her to take some time to recuperate."

Severus snorted in disbelief.

Albus arched a brow. "Is there a problem, my boy?"

"Ms. Dursley is operating under the mistaken belief that I am her mate."

"Are you certain you aren't?" Pomona Sprout asked.

"Of course, I'm certain. Do you think I would risk refusing her if I wasn't?" Really, did his colleagues think so little of him?

"Severus Snape, what did you do to that girl?" Minerva snapped at him, but Severus didn't answer her.

His attention was currently locked on the old man behind his desk. The one who winced when Severus said he was certain. The man who now wore a look that was a cross between shame and calculation. Albus pursed his lips and stared at his desk rather than meet anyone's gaze.

"What did you do?" Severus asked. His voice was low but lethal.

Dumbledore's eyes jerked up to meet the potion master's. "Now, my boy, you must realize that I was only trying to help."

"What did you do?" he asked again, drawing the words out this time.

The headmaster licked his lips nervously. "You have to understand that you were so distraught by the time I found you after the attack. I did what I thought best."

"Albus," Minerva said with a sour expression, "answer the bloody question."

Severus gave her a nod of thanks before turning his attention back to Dumbledore.

Albus sighed. "I placed a block on your mate bond."

Everyone in the room was deathly silent as they stared at the man in fervent disbelief.

He rushed to explain himself. "You were devastated after Samhain. Weeks passed and you were barely functioning. I thought if I blocked the link so you couldn't feel it, it would ease some of your pain. And it did. You weren't yourself, but you were so much better."

"My mate died! Of course I was devastated. I had every right! You had no right to take my grief from me. No right." Severus had never felt more disgusted at this old coot than he did at that moment.

The other three heads of house made noises of surprise. "Lily was your mate?" Sprout asked.

He closed his eyes and shook his head before looking back at them. "No. Cassiopea Lestrange. Bella and Rodo's daughter. Aurors attacked and burnt the cottage they were living in the same night the Potters died. Cassie was a babe. She was in her crib on the top floor, right where the fire started. They couldn't get to her. It's why they attacked the Longbottoms. They were part of the raid that killed their only child."

Albus winced and dread filled Severus. He didn't want to ask but he had to know. "What?"

The headmaster cringed and curled in on himself as he tried to hide. "We couldn't allow the child to grow up on the Dark side. For the greater good, she couldn't be allowed to remain in that house."

Snape staggered back as a feeling of absolute betrayal swamped him. "You ordered them to kill my mate?"

Albus' brows shot up and he held his hands up. "No, of course not, my boy."

"I think you better explain, Albus," Filius stated with a furrowed brow. None of them were liking what they were hearing from their headmaster.

The old man sighed again. "Alice and Frank were working with the order. They took the child to a safe location and started the fire to make the Dark believe she was dead. Unfortunately, they were driven insane before they told anyone where they placed the girl."

Severus' knees went weak and he fell into a chair some conjured up beneath him. His hands trembled as he felt true hope for the first time since he'd lost his mate. "Are you telling me she's been alive this whole time? She's been alive and alone for sixteen years?"

"Initially I believed your grief to be for Lily Potter. It was much later when I discovered your mate was someone else. By then, it had been much too long. There was no hope of finding the child. I felt it was better to allow you to continue to believe she was completely beyond your reach."

Tears fell from onyx eyes. "That wasn't your choice to make."

"You would have obsessed over her," Albus argued. "You had other matters you needed to focus on. It was for the greater good."

Snape snarled. "Fuck you and your greater good, old man. I'm not your puppet anymore. I quit. And get this bloody block off of me."

"My boy—"

He shoved himself back to his feet. "I am not your boy. Remove it or so help me I will have you up on charges with the Ministry and the vampire council for interfering with a mate bond."

Albus' sigh was completely defeated. "Of course." He moved his wand in a complex pattern and muttered several phrases in Latin. After a moment, Severus suddenly felt lighter, freer. Whole. Even if he could feel that annoying persistent ache telling him his mate was too far away. But that meant she was alive. Alive and very much his. Merlin, he was going to kill this old fool.

"Where is she?" he asked.

Dumbledore furrowed his brow. "I told you, we don't know."

Severus rolled his eyes. "Dursley."

"She went home."

He shook his head immediately. "She wouldn't. She hates it there."

"Perhaps Miss Lovegood would know," Filius suggested. "I'll ask her and get back to you as soon as possible."

"Thank you." And in a flash, Severus was gone, using his enhanced speed to take him to his rooms. He wished to be packed and out of Hogwarts as soon as possible.

He was surprised to find your best friend sitting on the floor outside of his office. "Miss Lovegood?"

She gave him a dreamy smile as she got to her feet. "Hello, Professor. Or should I not call you that any longer?"

He had long ago ceased questioning how the blonde knew the things she did. "Where is she?"

Luna tilted her head and looked him over. Her eyes shone with a clarity she rarely possessed. "Why?"

"Please." His voice broke with the word. He couldn't explain this to her. Couldn't get out the words through the knowledge that he may have irrevocably injured his mate. He just needed to find you. To confirm you were who he now thought you to be. He couldn't let another day go by without you in his arms.

She hummed and shrugged. "She went home."

He shook his head. "She wouldn't return to the Dursleys."

"That was never her home."

"Your place then?" It had to be. There was nowhere else for her to go.

She gave another soft smile and shook her head. "She's always welcome but daddy's in South Africa looking for whumplesnuffles."

Snape blinked. What in Merlin was a whumplesnuffle? "Then where?" He sounded desperate, he knew it, but he didn't care.

"Daddy was most curious when her creature inheritance came through. Took her to Gringotts himself."

His brow furrowed. "She told me she hadn't been tested."

"Did she?" she said before heading down the hallway. Severus could only watch her go as he tried to recall the conversation with you in his office but the exact words escaped him. Damn it. He huffed a breath and entered his rooms to pack. He had no desire to return here if he didn't have to.

***

Mere hours had passed when Severus found himself standing in front of the gate to Lestrange manor. He hesitated, staring at the once familiar home. It had always been overly large in his opinion. Of course, Bella had thought so too. That's why the family had been living in their cottage rather than here with Rodo's father. Severus shook the thought away.

He hoped this is what Luna had been trying to tell him. That you were his Cassie and you'd come home. But what if he was wrong? That's why he hesitated. What if you weren't her? What if he never found her? But why else would you claim to be his mate? It was the only thing that made sense.

After taking a deep breath for courage, he laid his hand against the gates. Evidently, he was still keyed into the wards as the gate silently swung open to admit him. He made his way to the door which opened as he neared it. A familiar looking house elf watched him with a tilt of its head. "What cans Mopsy bes doings for you, Mr. Snapsey man?"

The corner of Severus' mouth twitched. "Hello, Mopsy. I am hoping your mistress made her way home. I need to see her."

The elf's eyes narrowed. "They said Mistress Cassie was dead. Hows she come home if she dead?"

He hummed in agreement. "That is what they said. Is she here?"

"I thinks you better come in. Youse not well thinking dead peoples be here." With that she stepped back to allow him in the house. "Youse waits here." The elf disappeared with a pop.

Severus closed his eyes and tipped his head back with a groan. Mopsy hadn't explicitly stated you weren't here, but it wasn't looking good. He pinched the bridge of his nose and sighed. Maybe you were just another student and his mate would be forever lost to him.

"Why are you here, professor?" Your soft, sweet voice startled him from his contemplation.

His eyes flew open and his spine straightened. He looked you over from top to bottom. How was it you looked so much worse than you had even that afternoon? His heart ached at the knowledge that he was the cause of your unhealthy appearance. But now that you were here in front of him, there was no question that you were his mate, his Cassie.

***

When the silence stretched, you wrapped your arms across your stomach and hunched your shoulders as if that could protect you from the world around you. Protect you from this man in particular. You kept your gaze turned from him, not wanting to see that look of hatred and sadness he seemed to don whenever you were around lately. And it would probably be worse as he'd obviously been sent to "fix" you.

You rolled your eyes at the thought and took a step back. "There's no reason for you to be here, professor. I assure you, I will be fine in time. You can return to your duties."

"Wait," he said, his voice sharp, quick.

You jerked your head up in surprise and met his gaze. You couldn't place the emotion on his face as he gave you a crooked smile. "Why?" you asked with a tilt of your head. If he was feeling guilty, you didn't want to hear it. You had no interest in making him feel better when you still felt like shit.

He ran a hand through his hair and took a step toward you. When you made to move again, he held his hands up in a placating gesture. "Why did you tell me you hadn't been tested?"

"I didn't. I merely stated that the tests were expensive. Xeno paid when he realized what sort of creature I was. I wasn't exactly thrilled to discover who my parents were. As if Harry needed another reason to hate me." You shrugged and turned to head toward the sitting room. Severus could either follow you or not. When you arrived you made a beeline for the small bar at the side of the room and poured yourself a healthy serving of Dragon Brandy. "Help yourself," you told Snape as you took a seat.

He lifted the bottle you'd used and sniffed it. He nodded in appreciation and poured himself a glass before sitting in the chair across from you. His tongue traced his bottom lip as he studied you for a moment. "You had to know I wouldn't care about your parentage."

"I had a feeling you wouldn't and I intended to tell you after we'd dealt with the issue of you being my mate, and...well, you know how that went. Why are you here, Sev—professor?"

He shook his head. "Not professor. Not anymore. I tendered my immediate resignation."

You arched a brow at that. You knew he hated his job but were surprised he'd leave it so abruptly. "Why?"

Severus took a deep breath and licked his lips before launching into the story of his mate and Dumbledore's unwanted, bumbling interference. You were horrified by the time he finished.

"You thought me dead for fifteen years?" You'd been suffering thinking he'd rejected you but you couldn't fathom thinking he was gone forever. The heartbreak you would feel.

"Sixteen." His voice nearly broke and he cleared his throat. "It's been sixteen years."

He crossed the room in long strides and knelt in front of you, taking your hand in his. "When you told me that I was your mate, I had a brief moment of happiness before I realized it was impossible. My mate was gone. And as much as I might wish for you to be her, I thought it impossible. If I could chose anyone to be tied to for eternity it would be you."

He lifted your hand and pressed a kiss to the inside of your wrist before laying your hand against his cheek and closing his eyes. "I am so sorry for the things I said. For not finding you all those years ago. I can only hope to make it up to you."

You studied him for a long moment. "You hurt me, Severus."

He winced as if the words physically pained him. "I know."

You lifted your free hand to cradle his face. "Don't do it again."

Then your lips found his. You smiled against his mouth as pure euphoria flooded through you. If there had been any lingering question as to your identity it was long gone. There was no doubt you were the potion master's mate.

With the connection between you affirmed, all the broken pieces of your heart settled back into place. It was still tender, still fragile, but for the first time since his rejection, you believed it could be healed. Severus deepened the kiss as he pulled you from the chair and into his arms. A moment later he was sitting on the floor with you straddling his thighs as the two of you desperately tried to get closer.

Finally, you pulled back and rested your forehead against his. "You can't hurt me again, Sev. Not like that. I won't survive it a second time. I thought I'd lost you before I'd even had you."

He leaned back and lifted your chin so you were looking in his eyes. "I will cherish you every day for the rest of our lives. Just love me and I will give you everything you desire."

You grinned. "The only thing I need is you. Just you."

He kissed you again, short and sweet. "And you have me, body and soul."