Olivia's POV

I spent the next hour or so designing my room the way I wanted it. I considered doing a green and silver theme, but, since I was no longer a student, it might've been a bit biased to do Slytherin colors. Instead I chose purple and silver. I made a large, king-size feather bed, with satin purple sheets and a black comforter, draped with purple and silver. A black wood chifforobe with a full-length mirror on the door with a skeleton key to keep my things locked up. A writing desk, made out of the same black wood, with drawers that locked.

When I was satisfied, I lay back on my bed, wand in hand, staring up at the plain ceiling. After a few tries, I charmed the ceiling so that the night sky and stars twinkled down at me. Unlike the ceiling of the Great Hall, it would not change as the weather changed, but would remain the night sky. Pleased with myself, I attempted to create the Aurora Borealis, but for some reason couldn't get it quite right. I ended up producing a slew of bubbles with the colors of the aurora.

I became aware, suddenly, of the feeling of someone watching me. I glanced up to see Snape standing in the doorway, looking faintly amused.

"What are you doing?" he asked, shutting the door and coming to sit on the edge of my bed.

"Trying to recreate the Aurora Borealis," I said with a shrug. He frowned a moment, looking up at the sky on the ceiling. He pulled out his own wand, concentrated a moment, then waved it wistfully. The lights erupted from the tip of his wand and took their place in the night sky.

"Brilliant," I said, looking up in awe. "…What did Dumbledore want?"

"He's leaving for the evening again and wants me to stay here."

"So…it's just us here?" I asked with a sly smile.

"Us and the others who live in the castle- Trelawney and Filch."

"Well they hardly count. Why don't we go to your office?"

"What's on your mind, little girl?"

"Take a wild guess," I said, grinning. "For once, Dumbledore isn't here and we practically have the entire castle to ourselves."

"Aha," he said, his black eyes glinting. He took my hand and pulled me to my feet. He kissed me eagerly, then led me down the hall to his office.

When we reached his office, he shut the door. He barely had time to put all of his enchantments in place before I was kissing him. I pinned him against the door and began to unfasten the buttons of his shirt. I had dreamed of this so many times, being together in his office…in the Potions classroom…

"Well, I'm not sure we can do it in the Potions classroom," Snape said with a smirk, breaking my kiss. "Considering it's no longer my classroom."

"You are way too comfortable in my head," I said and resumed kissing him. He tolerated my being in control, but not for long. He soon scooped me up and I let out a squeal as he deposited me on top of his desk. While he busied himself ridding me of my pants, I reached out with one hand and swiped all of the papers off his desk and onto the floor.

"Those were in order…You're going to pay for that, little girl," he said with a growl. I let out another delighted squeal as he rid me of my jeans and tossed them aside. With one swift movement he parted my legs and pushed inside of me. I was already soaking wet.

"Well aren't we the eager one?" he teased as I wrapped my legs around him.

"You always did have that effect on me," I replied with a sly smile.

I groaned and leaned back on my elbows as he began to move inside of me. I thought it would be quick, but I was wrong. Every time I got close, he would stop and pull almost all the way out- punishment, I'm sure for knocking his papers to the floor. After an agonizing 45 minutes, I was practically begging for it.

"Come on, Severus," I said, panting, sweat dripping down my face. "This is torture!"

"Say you're sorry," he said tauntingly.

"I'm sorry!" I said immediately. "Now please!"

With a deep chuckle he scooped me off the desk and turned me around. I braced myself, holding onto the edge of the desk, as he entered me from behind. This time it was quick and when we were both spent he collapsed back into his chair, pulling me into his lap.

"I love you," I said once I had regained my breath. He smiled and brushed my damp hair out of my face. He kissed me once more and sighed.

"I love you, too."

The start of term came quickly. When it came time for the Hogwarts Express to depart from Hogsmeade to pick up the students, Snape walked me down to the village. Dumbledore had asked that I ride along, for extra protection. I had forgotten that Tonks was supposed to be there until I saw her on the platform. I smiled when I saw her, but she still looked as depressed as she had at the start of the summer. Still, she offered me a weak smile. I turned to say goodbye to Snape.

"I'll see you when I get back," I said to him.

"Yeah, alright," he said stiffly. I could tell he was uncomfortable being around Tonks. I let out a 'hmph', stood on my tiptoes and, very pointedly, kissed him on the cheek. He let out a 'hmph' of his own and turned on his heel and stalked back towards the castle.

"You two fighting again?" Tonks asked as I approached her.

"No, he's just being his usual grouchy self," I said, rolling my eyes. "How've you been?"

"Fine," she said with a shrug. "…I'm stationed in Hogsmeade this year, for extra protection."

"Is it just you?"

"No, a few other Aurors are here as well- Proudfoot, Savage and Dawlish. It's just you and me on the train, though. Reckon Dumbledore thought we could handle it ourselves. …Have you heard from Remus at all?"

I shook my head.

"No. Have you?"

"Not really. Guess it doesn't matter," she said wistfully.

Tonks cheered up a little when we got on the train and it started moving.

"Hard to believe it's been almost a decade since I've been on the Hogwarts Express," she said, grinning as she looked around. "It's just like I remember it!"

We spent most of the ride up front with the driver, which was fun. I'd never been to the front of the train before, I'd always remained in the Slytherin compartment at the rear of the train. It was interesting to see how the steam engine worked.

Tonks got off the train at Kings Cross Station to oversee the students as they were boarding. Looking out the window, I could see a few more Aurors escorting Potter and the Weasley family onto the Platform.

As the train pulled away from the station, Tonks came back up to where I was waiting.

"I think it's best if we move along the train, keep an eye on things," she said to me. "I'll stay towards the front of the train and you head towards the back- those are your people anyway."

She was right, of course. As I reached the Slytherin compartment, trying to look as confident and unconcerned as possible, people began to recognize me. I greeted a few people. To those who asked- and you'd be surprised how many didn't- I said that Dumbledore had offered to let me stay at Hogwarts, for my own protection and to help the Aurors guard the castle. I saw Draco with his friends and, though we had seen each other several times when the Dark Lord called meetings, he ignored me. I wondered what he was planning for his mission. Did he already have something in mind or was he just winging it?

When the train got close to Hogsmeade, I made my way back up to the head of the train. Tonks was waiting for me.

"You can walk with the students back up to the castle," she said. "I'm going to do one last sweep of the train…"

"Okay," I said with a shrug.

I followed the students back up to the castle. I got a carriage all to myself. I kept my wand out and continuously glanced over my shoulder for any sign of anything…conspicuous. But I saw nothing. When we reached the gates of the castle, the carriages stopped and everyone was searched by a couple of Aurors and Filch with a strange wand-shaped object that he waved over everyone. The Aurors had obviously been alerted to my presence, however, because they simply nodded to me and allowed me to go on.

Upon reaching the castle, I decided not to attend the start-of-term feast. After all, there was no real place for me there- I didn't want to sit with the students and I definitely didn't want to sit with the teachers. Instead I made my way down to Snape's office to wait for him. I found a couple of house-elves there, tending to the fireplace and dusting. Both looked terrified when I entered and prepared to leave, but I stopped them.

"You don't have to look so frightened of me," I said gently. "I didn't mean to disrupt your work."

"House-elves aren't meant to be seen, miss," said one.

"Nonsense. I used to visit the kitchen all the time and get extra food to feed…stray dogs," I said quietly. This was the first time I had thought of Sirius Black in ages and I felt a pang of sorrow at his death…even if he had annoyed me, he had been a good person.

"I don't suppose you could bring me a plate and something to drink?" I asked the elves. "I'm not going to the feast."

"Of course, miss. We'll be back in just a minute."

When the elves had left I sat down in Snape's chair and put my feet up on his desk to wait.

Snape's POV

I was about halfway done eating when I saw a ragged-looking wolf-shaped Patronus come into the Great Hall and approach the staff table. At first I thought it was Olivia's Patronus- my heart skipped a beat, thinking perhaps something had happened to her- but the voice that came out of the beast's mouth was Tonks'.

Harry Potter was delayed on the train. Meet us at the gate. Then the beast vanished. I sighed and pushed my plate away. I leaned over and quickly told Dumbledore what had happened. He looked relieved- he had been uneasy ever since the students poured into the hall and we had not seen Potter's face among them.

As I left the castle I sighed and looked up at the sky. It was a beautiful night. I wondered if Olivia was with them or if she had already returned and was in her room.

As I approached the gate, I saw Potter standing beside the miserable-looking Tonks.

"Well, well, well," I sneered as I tapped my wand on the chain that bound the gates and they began to come undone, "Nice of you to turn up, Potter, although you have evidently decided that the wearing of school robes would distract from your appearance."

"I couldn't change, I didn't have my-" Potter began.

"There is no need to wait, Nymphadora, Potter is quite- ah- safe in my hands," I said to the brown-haired woman, eager to get rid of her.

"I meant Hagrid to get the message," she replied, frowning.

"Hagrid was late for the start-of-term feast, just like Potter here, so I took it instead. And incidentally, I was interested to see your new Patronus."

I moved aside to let Potter pass and then shut the gate. I tapped the chain again with my wand and it locked itself again.

"I think you were better off with the old one," I said maliciously, "The new one looks weak."

There was a fleeting look of shock and anger on her face, which I had been aiming for. I turned away from her quickly, triumphant.

"Good night," Potter called over his shoulder to her, "Thanks for…everything."

"See you, Harry," she said miserably.

"Fifty points from Gryffindor for lateness, I think," I said to Potter as we walked back to the castle, "And, let me see, another twenty for your Muggle attire. You know, I don't believe any house has ever been in negative figures this early in the term: We haven't even started pudding. You might have set a record, Potter."

Potter didn't say anything but his fury was apparent. I savored this taunting for a moment before continuing.

"I suppose you wanted to make an entrance, did you?" I continued, "And with no flying car available you decided that bursting into the Great Hall halfway through the feast ought to create a dramatic effect."

Potter still didn't speak. We walked up the steps and through the doors. We paused in the entrance hall where Potter was thinking he might could slip on his invisibility cloak.

"No cloak. You can walk in so that everyone sees you, which is what you wanted, I'm sure," I said to him. Furious, Potter stomped away from me, through the open doors. Every eye in the room was on Potter and I smirked as I returned to my place at the staff table.

A while later Dumbledore got to his feet to address the room as soon as the plates were cleared.

"The very best of evenings to you," he said, smiling with his arms open wide. Everyone in the room saw his blackened hand. A few gasped loudly. Dumbledore merely smiled and shook his sleeve down over the injury.

"Nothing to worry about," he said lightly, "Now…to our new students, welcome, to our old students, welcome back! Another year full of magical education awaits you. Mr. Filch, our caretaker, has asked me to say that there is a blanket ban on any joke items bought at the shop called Weasley's Wizard Wheezes.

"Those wishing to play for their House Quidditch teams should give their names to their Heads of House as usual. We are also looking for new Quidditch commentators, who should do likewise.

"We are pleased to welcome a new member of the staff this year. Professor Slughorn is a former colleague of mine who has agreed to resume his old post of Potions master."

The while hall broke out in muttering as everyone was unsure if they'd heard right. I smiled inwardly.

"Professor Snape, meanwhile, will be taking over the position of Defense Against the Dark Arts teacher," Dumbledore continued over the noise.

"No!" said Potter loudly from the Gryffindor Table, not caring that a number of people heard him and were staring at him. I glared at him, but even Potter couldn't bring me down. There was nothing he could do about the appointment anyway. The Slytherin Table broke out in cheers and applause and I raised my hand in lazy acknowledgment.

Dumbledore cleared his throat loudly and the chatter began to die out. He waited until there was absolute silence before continuing.

"Now, as everybody in this hall knows, Lord Voldemort and his followers are once more at large and gaining in strength. I cannot emphasize strongly enough how dangerous the present situation is, and how much care each of us at Hogwarts must take to ensure that we remain safe. The castle's magical fortifications have been strengthened over the summer, we are protected in new and more powerful ways, but we must still guard scrupulously against carelessness on the part of any student or member of staff. I urge you, therefore, to abide by any security restrictions that your teachers might impose upon you, however irksome you might find them- in particular, the rule that you are not to be out of bed after hours. I implore you, should you notice anything strange or suspicious within or outside the castle, to report it to a member of staff immediately. I trust you to conduct yourselves, always, with the utmost regard for your own and others' safety.

"But now, your beds await, as warm and comfortable as you could possibly wish, and I know that your top priority is to be well-rested for your lessons tomorrow. Let us therefore say goodnight. Pip pip!"

I was eager to go and find Olivia and left the staff table without hanging around to chat- not that I ever did. I had just made it out of the Great Hall when a voice from behind stopped me.

"Severus, my boy, how are you?" called a booming voice. I cringed, then forced a smile and turned to see my old Potions teacher.

"Professor Slughorn," I said. "I'm fine. How are you?"

"Good, good…though I certainly didn't think I'd find myself teaching again! And call me Horace, Severus, we're equals now. How have you enjoyed my old job?"

"Well enough," I said with a shrug. "The students, well, they're mostly idiots when it comes to Potions…but the few who have a real knack for it make it really worth it."

I was thinking, of course, of Olivia.

"That was always my philosophy as well," he said with a chuckle. "Why don't you come up and have a cup of tea? We can discuss the classes, there's a few students I'd love to talk about…"

"I've got something I need to check on first…Horace. Perhaps in a minute?"

"I'll be waiting," he promised and started up the stairs.

"Oh and Horace?" I called and he stopped. "…Mind if I bring someone?"

"By all means," he said curiously, then continued up the stairs.

Olivia's POV

I was lounging in Snape's chair, reading one of his books, when his door opened. He took a moment to look me over. I had my feet up on his desk and didn't attempt to stop him from looking up my skirt.

"Nice," he said with a smirk, shutting the door behind him. "How was the train ride?"

"Boring," she said with a shrug. "And Tonks is so…depressed."

"I know. I saw her just a moment ago."

"What? Where?" I asked.

"Apparently, Potter was…delayed on the train. She escorted him up to the castle."

"Aw, something happened and I missed it? What delayed him?" I demanded.

"Draco, I believe. Potter's nose was broken."

"I always miss the good stuff," I grumbled.

"Her Patronus has changed. Did you know?" I asked her.

"No. I didn't know they could change."

"Yes, very rarely, due to a…heavy emotional blow or traumatic event."

"What's her Patronus?"

"A wolf. It looks like yours, only more ragged."

I scowled at this.

"I wish mine would change," I said with a sigh.

"I think perhaps yours was meant to be a wolf," he offered. "…It does suit your personality."

"You think?" I asked with a smile, getting up out of his chair. He allowed me to kiss him once, then clasped my hands in his.

"There's someone I'd like you to meet," he said.

"Who?" I asked, frowning.

"Horace Slughorn has invited us for tea."

I followed Snape curiously up the stairs to the office usually occupied by the Defense teacher. We passed McGonagall on the stairs who smiled and nodded when she saw me. She had been a lot nicer to me ever since I'd helped heal her in St. Mungo's.

"So, why exactly does he get the good office?" I asked curiously as we headed down the corridor.

"Because it was one of his conditions on returning as a teacher and because I like my office," he replied. "It's…homey. And it's close to you."

This made me smile and I was still smiling when he knocked on Slughorn's door. The door was opened by a large, walrus-looking man. He beamed at us.

"Come in, come in, Severus," he said. "And who is this you've brought?"

"This is my…cousin, Olivia Cain. She graduated last year, but Dumbledore offered her a place to stay, since…well, it isn't really safe for a young woman to stay home alone. Here, I can keep an eye on her," Snape said, smiling when he saw me scowling at him.

"He's right, you know. These are mad times we live in. Pleased to meet you, Miss Cain. I'm Horace Slughorn," he said, shaking my hand.

"Olivia is by far the brightest Potions student I ever had the pleasure of teaching," Snape said, causing me to blush faintly. "She was my apprentice from her second year, up until she graduated."

"A pity you had to graduate, right before I came to teach," Slughorn said disappointedly. "I would have loved to see you at work. It's always a thrill to come across someone with a passion for Potions."

"If you ever need any help with anything, I'd be glad to assist," I offered quickly. "I used to help Severus teach some of the younger classes."

"She's quite capable," Snape assured him.

"I might just take you up on that offer," Slughorn said. "It's been ages since the last time I taught and it might take me a while to get back into the swing of things."

We sat and sipped tea with Slughorn for a while. I was content just to sit back and listen as they discussed various students, including Potter. Slughorn seemed disheartened to hear the boy was a menace at Potions, but it was true. They talked about other students- who had potential, who was hopeless- and Slughorn talked a little about the old days, though Snape seemed uncomfortable with this. Though I didn't speak much, I could tell Slughorn liked me immensely.

"Who were your parents, Olivia?" he asked as he poured me another cup of tea. "You said you were Severus' cousin?"

"Yes, sir. Ellen Cain was my mother. …I never knew my father," I said.

"Oh, Ellen, I remember her. Not particularly outstanding at Potions, but always had her nose in a book, that girl did. How is she?"

"She died," I said somewhat coolly. "Several years ago."

"Oh, I'm so sorry, my dear," Slughorn said, meaning it. He put his hand on my arm sympathetically.

"It's okay," I said with a shrug. "Severus was kind enough to take me in when I didn't have anywhere else to go."

"Oho! So that's where you get your talent for Potions?"

"I take no credit for that, Horace. She was talented before I got her," Snape said with a smile. "…It's getting rather late, isn't it?"

"So it is!" Slughorn exclaimed. "I'm still not used to having to get up so early and prepare for classes. Olivia, why don't you come around tomorrow afternoon? You could help me with my first years."

"I'd be delighted, sir," I said as we stood to leave.

"Excellent! I look forward to it," he said, smiling.

I followed Snape out of Slughorn's office and we started back down to the dungeons.

"Not going to steal you away from me, is he?" Snape teased lightly.

"Ew," I said, wrinkling my nose. "No thank you!"

He laughed at me.

"Want to see my new classroom?" he asked, smiling wickedly. I nodded eagerly. He had strictly forbidden me from coming into his classroom until he was finished decorating it. When we reached the bottom of the stairs, instead of going into the dungeons, we slipped down the corridor that led to the Defense Against the Dark Arts classroom.

There were no teacher's quarters down this corridor, just the empty Muggle Studies classroom. It was completely silent, almost like we had the whole castle to ourselves. Snape opened the door to the Defense classroom using a spell and used his wand to light the candles. I peeked around him into the classroom and gasped.

Thick black curtains had been drawn over the windows so that, even if it had been daytime, no light would have shown through. Gruesome pictures were hung on the wall, depicting the effects of various curses. There were books on the Dark Arts lining the shelves, some of them I recognized from home.

"Wow," I said in awe. "It's so…Dark. And scary. You're going to make some poor first year wet their pants."

"Well, that is the point," he said sardonically. "Not the pants-wetting part, but…They should be scared. We live in scary times."

"True."

I went over to his desk and sat down with my feet up on his desk. It was the same chair and desk that had been in the room when it had been Lupin's classroom. This prompted several memories of the two of us in his classroom, doing things on his desk… I bit my lip and glanced at Snape, hoping he hadn't noticed my thoughts, but he was walking around his classroom, looking at the paintings.

"Want to hear my course introduction speech?" he asked, looking at me with a wicked grin. "Since you won't be able to attend any of my classes this year…"

"Ooh, yeah!" I said enthusiastically. He motioned for me to get up out of his chair and go sit in one of the student desks. I obeyed, sitting in the desk directly in the front of the classroom.

"The Dark Arts," said Snape, moving swiftly across the classroom. "Are many, varied, and ever-changing, and eternal. Fighting them is like fighting a many-headed monster, which, each time a neck is severed, sprouts a head even fiercer and cleverer than before. You are fighting that which is unfixed, mutating, indestructible. Your defenses must therefore be as flexible and inventive as the arts you seek to undo. These pictures give a fair representation of what happens to those who suffer, for instance, the Cruciatus Curse, feel the Dementor's Kiss, or provoke the aggression of the Inferius."

A chill crept up my spine and I shivered delightedly. I smirked and he lost his concentration.

"From there I segue into nonverbal spells," he said. "What do you think?"

"I think you look…extremely sexy when you talk about the Dark Arts," I said in a sultry voice. "Professor."

"It's not supposed to be sexy, it's supposed to be ominous," he said, rolling his eyes at me.

I licked my lips and looked him over, wondering if he would let me…

"Although," he said, catching my eye and grinning. "I guess I could work with sexy…"

I stayed seated in the little desk and he came up behind me. He began to kiss my neck and I let out a small gasp as I felt him nip me in what was sure to leave a mark in the morning. I felt him smirk against my skin.

"Stand up," he commanded. I did as told and he pulled me into him, kissing me hungrily.

"I love it when you tell me what to do," I said, biting his lower lip. He raised an eyebrow at me, then glanced towards the door. He pulled out his wand and waved it, casting several nonverbal enchantments. Then he laid his wand on a desk and put his hands on my hips, kissing me again. I could feel his growing arousal.

"Get on your knees," he said in that amazing dark voice of his. I shivered delightedly and dropped to my knees on the hard floor. I didn't wait to be told- I quickly undid his pants and released his hard cock. I suppressed the urge to take it in my mouth immediately, beloved plaything of mine that it was. I looked up at him, waiting for instructions.

"Suck me," he hissed. I eagerly obeyed, flicking my tongue over the head several times, tasting what I had come to love so dearly. Then I took him as far in my mouth as I could and looked up at him. He was watching me and he moaned softly when we made eye contact. I made a moaning noise of my own, knowing how amazing that would feel. I was right- he let out a little hiss and I felt him stiffen in my mouth even more. Slowly I moved back so that only the head of his cock was in my mouth. I swirled my tongue around the tip, then licked along the length of him, my hands at the base of his cock, lightly massaging his balls.

When I felt him pulse, he stepped away from me, taking his cock with him. I made a pouty face and looked up at him. He sat on the edge of his desk.

"Come here," he demanded. I bounced up eagerly and when I got close enough he grabbed me and kissed me roughly. I squealed delightedly when he pulled my shirt off over my head. My breasts were spilling out of the top of my black lacy bra and he quickly freed them. He fondled them as he kissed me, pinching lightly. Then he lowered his head and began to kiss and suck them. Then he nipped me gently, leaving a mark identical to the one on my neck. He lowered his hands and slipped them under my skirt, then stopped in surprise.

"You're not wearing any underwear," he growled in my ear. "That's very naughty of you, little witch."

I giggled and started to shimmy out of my little black skirt, but he stopped me.

"Leave it on," he breathed. I grinned wickedly and he lifted me up onto the desk with him. I placed my legs on either side of his waist. His cock stood at attention, mere inches from my opening, begging to be let in, but I waited for him to tell me.

"Lower yourself on to me," he commanded; then, without really giving me a chance to do it myself, he put his hands on my waist and thrust into me. I was wet and ready for him- I had been ready since before he finished his little speech. I wondered vaguely how long he had been working on that, but didn't have much time to ponder it as he told me to ride him- as if I needed telling!

We went at it into the wee hours of the morning. Finally, we exhausted ourselves and, after catching my breath, I began to locate my clothes. Snape glanced at the clock.

"I have class in two hours," he groaned.

"Yeah, whose fault is that?" I smirked. "You brought me down here and seduced me."

"I was just testing out my speech, I had no intentions of seducing you… At least, not conscious ones."

"By the way, how long have you been working on that speech?" I asked curiously.

"Years," he said, sliding open a drawer and pulling out a little black, leather-bound notebook. He opened it to a page and showed me where the speech was written down- several parts had been crossed out and rewritten.

"What is that, a diary?" I asked.

"No!" he said defensively. "…It's a journal…of sorts."

"You keep a diary and I don't know about it? How do I not know about it? Can I read it? What's in here?"

"Journal," he said emphatically. "And…no."

"Why, what do you write about?"

"Just stuff…Whatever pops into my head… sometimes potions stuff, sometimes just ramblings…quotes, dreams…"

He flipped absently through the book as he spoke. I was dying to know what was in it…but if he didn't want me to read it, I wouldn't.

"Well, now that you've piqued my interest, Mr. Mysterious, with your mysterious diary…I'm going to bed," I said, crossing my arms and sticking my tongue out at him. I headed for the door.

"Journal," he said forcefully, hurrying out after me.