The students in the school slowly noticed changes in Snape, unpleasant changes, just as Snape noticed the students more. Their bad behavior, their after hour perambulations, their heartbeats. At meals Snape was more cranky than usual, eating barely anything beside a few bites of meat and drinking little. Regular food seemed to no longer sit well. He would have to increase the potency of the medallion that let him eat… When he had time and blood to spare to heal him after he dug the enchanted piece of metal out of his arm.

His appearance also changed; while before he had looked slightly more healthy than usual, now he looked downright sick to a point where he seemed half dead, though his senses were anything but. At the slightest sound Snape was off to find the source with speed like a hunted animal.

The potions in class became increasingly hard to brew, and the slightest mistake or misbehavior meant a detention with Filch. Over the next five days Snape went from touchy, moved onto tired, and finally ended up searching for people to put in detention outside his own class. Though oddly none of the detentions were with him.

No one could guess why.

Dumbledore and some of the other professors understood of course, but most of them didn't know how bad it was becoming. Dumbledore was attempting to find another food source for Snape, but was having trouble finding something safe quickly. Chicken blood just wasn't cutting it, despite Hagrid's continuous offerings.

That Tuesday Snape was dismayed to find that Poppy had already sent the sample of blood from the replenishing potion accident to Saint Mungo's. As he stood solemnly staring at the place the vial had been, Poppy ran up behind him in a rush to get some ingredients for a badly hurt patient. Fraught with worry her body was going into overdrive, something Severus could smell, and hear. Before Poppy knew what was happening her wrist had been grabbed by the Potions Master, who was still staring at the cabinet.

"Severus, is something else wrong? I told you that…" Poppy's words caught in her throat as she noticed the slight red tint in the professor's eyes. "Severus… are you well, please let go of me… I need to help a patient." The grip on her arm slowly loosened and Snape walked out the door, the only sound the swishing of his cloak. Poppy took a few breaths and headed back to her patient.

That Friday night found Snape stalking through the halls with more fervor than usual. To anyone watching it would seem like he was angry, to someone looking closely it would seem like he was listening for something, and indeed he was. Every night Snape spent time listening for students out of bed, it was his normal duty yes, but now it was for other reasons too. And now it was every night instead of his usual schedule. The students however, seemed unwilling to sneak out at night recently. There were more teachers in the hallways than ever, Snape was not trusted to patrol them alone right now. However, a single Professor had yet to run into him at night. They'd heard footsteps, or see a robe, but there was never anyone there when they rounded the corner.

Snape had taken to listening outside the doors of student's dorms and professors rooms for periods of time. Blending in with the shadows, savoring the sound of human drums and rivers. He always made sure he was gone or leaving before another Professor showed up. Snape knew he would never get away with attacking a student outright, and the tempting thought still sickened him, thankfully. But he could dream. At least while he 'hunted' the hunger pangs were less. Any distraction from the aching in his gut and veins was welcome. Occlumency was keeping the red mist at bay still, but barely. It seemed something was missing, he'd been able to survive on nothing for about three months before he invented his potion, now, it'd been barely a week and he was as hungry as if it'd been half a year. He'd sworn that he'd read age meant he'd have to eat Less not more. Of course, that was assuming he'd been drinking actual blood for years instead of facsimile. He hadn't really thought of long term consequences of the potion, he hadn't expected to make it to the end of a normal wizarding lifespan let alone reach a vampire's. Still, he was highly disturbed by his sudden inability to block out his hunger, or the drums. Still, that he could deal with, as long as the red mist was kept at bay, he'd be fine. He could feel it all the time now, but it wasn't affecting his judgement, not yet. He was fairly sure at least.

As Snape stalked the corridors that Saturday his sharp nose picked up a smell that part of him yearned for, and another part did not wish to smell at all; blood. Following the scent was far too easy. Half starved he traversed the winding hallways with the ease of years and the fervor of the famished until he found the source. A young first year Hufflepuff with a badly cut arm was crying near a suit of armor, almost as if he was trying to hide. In the pitch black the student couldn't see him, but Snape could see as if it were midday. The large cut on the shoulder seemed to have been inflicted by a fall, but a bruise on his face looked as if it had been inflicted by a concussive spell. The bloody sword nearby was evidence that the boy had been pushed, and probably lost his balance and fell on the sharp instrument.

The smell of blood was as intoxicating as the heart beat, rapid from the effort of sobbing for what seemed like a good time. Instincts that laid in the heart of every hunter stirred, and Snape breathed in the scent with a slight hiss as he slowly stepped closer, pulling the smells over his tongue. The child jumped up, holding his arm as he did so.

"Who-who's there? I'm not scared of you, I-I'll fight! You can't hurt me more than you alrea-ady have you-you jerk!" The child let go of his arm to hold up his wand, but the flow of blood made him cover it up again. Snape sniffed the air and inched forward more. "I-I'm warning you! I-hiccup-I, sob…" The young boy fell to the floor and started sobbing again. The forlorn voice caught Snape's attention, as memories of another crying child beckoned through the need for survival. With relief and disappointment he took his wand from his sleeve and approached the boy.

"Lumos." The light cast was so bright the boy had to cover his eyes momentarily, letting the wound in his arm flow freely, and Snape frowned slightly. As the boy uncovered his eyes he squeaked in alarm. No one wanted to be caught out after dark by Professor Snape.

"I'm sorry Professor, I was reading for- and this bully, and it was late- my friends had gone back-" In his frantic attempts to explain why he was out after curfew the boy waved his arms wildly, causing the gash to spill blood faster.

"Stop moving you idiot, you are making your wound worse." The child flinched as Snape's voice cut him off. "Ferula." Bandages slid from Snape's wand, stopping the light. "This might sting. I know you can't see, but don't worry, I'm just cleaning your wound. Snape knelt down beside the child and his face hardened at being so close to what he wanted. Holding the child's arm tightly he began to speak in a crooning voice most would think not possible for the Professor to produce. The power behind the words hung in the air making it as dense as a humid summer day.

"Don't worry… relax, everything will be okay… close your eyes, relax, I'm just going to clean and bandage your wound… relax." The boy swayed under the vampire's unconscious mesmeric influence, tired and dazed. Keeping a tight grip on the boy's arm Snape bent over the wound to inspect it; it was deep, not long, and fortunately hit no bone and no tendons, a few nerves. Leaning closer the smell of blood filled his nostrils.

Snape's gums itched and the glamour spell broke, his teeth shimmered into view. His concentration wavered just enough, and slightly red eyes bled through the removal potion. Bending close to the child's arm the smell hit his nose and tongue again as he breathed out of habit. Slowly the man hardened by years in the Dark Lord's service bent his head, the prospect of breaking a week-long fast picking at his resolve. However half way there he froze.

No… no. He shouldn't. But if he didn't… He could feel the red mist floating at the edge of his mind, feel it pushing him to feed, drain the boy dry. No. He couldn't. He refused. The red mist backed off, but he could tell the worrisome thoughts that entered his head were at its behest.

If he didn't take advantage of this and weeks went by... If he took just the slightest bit now it would mean he wouldn't go mad later. Was it an excuse or a plan? Snape shook his head. It was both, he was still man, human, enough to admit that. And he leaned down.

Slowly his lips met the wound, then his tongue. The blood was velvet in his mouth and warm in his throat, the metallic taste subtlety mixing with the faintest hint of clover.

Slowly he began to drink, lightly at first, and then he began to pull harder. He was hungry, so hungry. Soon he was holding the boy in his lap, sucking vehemently on the wound. The emptiness in his veins was slowly filling up, there was warmth where there was only cold moments before. Did it matter where his meal was coming from? Who was it anyway? Did it mat- A small moan brought him back from his meal, looking down he saw that the boy was slightly pale. Cursing he used one piece of the summoned cloth to clean his spit from the wound and then he sanitized it with his wand before bandaging it. Looking around he saw the ground and the suit of armor covered in blood the boy had shed before he got there. Snape paused, then gritted his teeth.

"Accio blood." The blood rose from the ground and the sword the boy had cut himself on rushed towards Snape, who opened his mouth. After swallowing he paused, disgusted, sated, then picked up the boy and began marching to the infirmary. About halfway there the boy woke.

"What happened, where are we going?" The boy mumbled weakly, much to Snape's dismay. His red hair was short and messy, as wild as the freckles on his face as the boy looked up at the Professor. A face that was still damp with tears. Snape ignored the mild guilt that sat in his gut alongside his meal. It was this, or possibly kill someone in a week. The lesser of two evils he knew would comment. A few more minutes though…

"You lost more blood as I tried to clean the wound, you fainted. We are going to see Madam Pomfrey, and I suggest you tell her not only about the sword, but the bully who punched you and pushed you so you fell on it. She will sort it out."

The boy blushed and snuggled closer to Snape, close to falling asleep from exhaustion, too tired and thankful to remember that he was scared of this Professor that he hadn't even had a class with yet.

Snape heard a mumbled "Thanks Professor" as he walked along. His heart seemed to skip the proverbial beat; despite it not really beating, despite it being just a handy bit of charm work.

"You're welcome Mr. Banderknott."

"How-yawn- do you know my name, I haven't taken potions yet, Mom won't let me till second-yawn- year. Was pardoned."

"If I didn't know the names of all the students here I would be a dismal teacher indeed. Now go to sleep." The boy yawned one more time before falling into a deeper sleep. As Snape walked down the many winding corridors he resisted the temptation to take the boy back to his own rooms, which were closer. To heal the boy, as well as have him close by for… However, the boy's already pale frame quickly convinced him otherwise. As well as the fact that the thought occurred to him at all. It should not have. He kept walking.

Knocking on the door to the infirmary took more willpower than Snape cared to admit, but he did it nonetheless. Opening the door Poppy gasped, eyes wide.

"Severus, what did you do? What have you done?" She cried trying to pull the boy from Severus and back away at the same time.

"I have done nothing!" Snapped Severus, giving up the boy. "I found him on the floor near a suit of armor, bleeding to death after falling, or being pushed, onto a sword. I cleaned his wound and brought him here. Do not assume I would lose control of myself!"

Poppy stared at the Professor disbelievingly, and Snape felt the smallest twinge of guilt at the slight lie. In his hunger he had failed to calculate how much he should have taken. Still, one minute too long only meant a sick day for the boy, instead of death for someone else. He would tell himself this until the annoying feeling of shame left, it was the truth after all.

"Your palor is better than yesterday." Poppy said flatly as she held the boy tightly while waving her wand to check his vitals.

Snape looked at the boy, he was asleep, but he should still speak carefully. "There was some on the floor, it was insulting to stoop to that level, but I'd rather not have a fresh reason for people to want me dead. Now goodnight, and ask the boy about bullying, I don't want this to happen again." Severus' robes whipped around the corner seconds later, leaving a bewildered Poppy to care for the boy.

Only when he reached his quarters and locked the door behind him did Snape stop to relax and slide into the green and blue leather chair in front of a quickly lit fire. Only then did he think about what happened. Only then did he curse himself for feeding on the boy too long. Holding his head in his hands he muttered to himself.

"Why did I not keep some of that blood for later, I can't expect a meal every night." Sighing, Snape shook his head and ran his fingers through hair that was slightly oily. Getting up he undressed and prepared for a fitful night.

Next morning as Snape ate some rare bacon wishing for something more raw, McGonagal sat down next to him and pushed a large vial of red liquid at him. Looking at the vial Snape could tell it was blood. Turning his gaze toward McGonagall he asked a silent question, to which she just pursed her lips. She was not going to say whose it was; if she had gotten it from Poppy, a fight in the halls, a donor, or herself.

"Make it last." She said before going back to her bowl of fruit. Snape nodded and slid the vial into his robes. He didn't need a meal every day. He'd have a drop later that night before bed to see whose blood it is and what condition it was in, but not now, not when he had eaten last night. He went back to munching on his very rare bacon waiting for his first class, but as usual though he left before everyone else. On his way to the dungeons a familiar smell hit his large nose; blood, fresh.

"This will be the end of me, and quite possibly someone else as well." He muttered to himself. He set off to find the source. He heard the problem long before he saw it. Two students were dueling, loudly.

"Expelliarmus!"

"Protego!"

"Furnu-!"

"ENOUGH!" Snape said as he rounded the corner. Both boys were startled out of the duel and the half finished spell ricocheted off the ceiling. Snape hit it aside and into the wall as he walked toward the wide eyed students. One was a Ravenclaw and the other Gryffindor, both second year students. One sported long yellow hair that grasped his ankles while the other had tattered robes that smoked slightly and were spattered with red. Snape pointed to the one with tentacled hair. "Finite incantatem!" The hair stopped struggling but remained ankle length. "Report to Filch at 9 o'clock tonight for detention, both of you. You," Snape said to the boy with tattered robes, "infirmary now, you're bleeding from a vein."

The boy jumped a bit and looked confusedly at his professor. "What? Where? How can you tell?"

Snape pointed at the floor, which had a spattering of blood on it, and then to the boy's neck which had a thin steady stream of blood flowing across it. He flicked his wand and the wound started to close, but far more slowly than if the mediwitch cast it, and it would scar. Pomfrey might be able to fix that, it would serve the child right if she couldn't.

"That kind of flow is created when a vein is cut directly, now go before you faint from blood loss. I must believe you are delirious from lack of blood already because only a nitwit would fight in these halls so brazenly. And minus 100 points from both your houses for fighting, and no, I am not interested in why this miserable excuse for a duel was started. Now both of you Go!"

The boys scrambled to comply.

"And do something about that atrocious hair before class!" Barked Snape as they rounded the corner. He pinched the bridge of his nose. "This will be the death of me." Snape looked at the floor and the blood, and sighed. He quickly looked around to confirm the emptiness of the hall, including that of portraits.

"Accio blood." He muttered and ushered the meager flow into a vial from his robes as he walked by it, hurrying to his first class of the day.

The first half of the day was uneventful, if tiresome from fighting, incompetence, and unruliness. At midday Snape took lunch in his quarters, drinking the miniscule amount of blood from the skirmish he stopped earlier to relieve a pounding headache brought on by a melted cauldron and a nearly chopped off hand. He then went to prepare for his NEWT level class of Slytherins and Ravenclaws and sighed, this was going to be a long class. Many of the ingredients used in the potion they were going to be making need to be sliced, diced, or cut into strips. Snape fervently hoped there would be no accidents, despite the rivalry to show off and see who was more knowledgeable, often by sabotage.

Everything was fine until the end of the class when a Slytherin boy threw a firecracker under the table of a Ravenclaw who was cleaning up. Snape saw it of course, but since most of the potions were already gone he deemed it not to be hazardous. Unfortunately, it did startle the Ravenclaw, and his knife dropped onto the table. It quivered, its pointed end embedded in the wood, pinning the tiniest bit of the skin between two of the boy's fingers to the table. It bled sluggishly.

Snape could, of course, smell it. The boy wouldn't need much besides a small healing spell, which he could manage himself. He walked up as the boy tried in vain to pull the knife out of the table and his hand. Looming over the boy unnoticed he breathed deeply. To those looking on it would seem he was trying to calm down, when really he was just enjoying the smell. He sighed and opened his eyes.

"You will never-" Snape's words startled the still jumpy student who got a burst of strength from it and pulled the knife out as he turned toward his feared professor. Still holding the knife out it went deep into Snape's stomach, two inches deep. As the professor's black robes grew wet very quickly the students' eyes also grew wide with horror. The young boy let go of the knife, his hands over his mouth in fear.

"P-Professor! I-I-"

Snape put his hand to the growing wet spot in shock for a moment, but quickly grabbed the knife handle and pulled it out. More blood rushed out as the only thing that was stopping it was removed. Snape could smell his own blood, and was very aware of how much he was losing with how wet his robes were growing, even through his multiple layers of clothing.

Suddenly, he was very Thirsty.

"Get out. Get out. Get all of your things and leave. Mr. Flory, Mr. Slazor, detention, see the Headmaster immediately. Leave, NOW! EVERYONE!"

The students were already gathering their things and banishing cauldrons before the sentence was completed. Not 15 seconds later the only thing left in the room was Snape, and the bloody knife. He focused on not allowing the wound to heal, using the blood he sorely needed. However, that is not something someone can easily control, and the wound started to close against his wishes. Pointing his wand at the now slowly bleeding gash the tired wizard shot a healing spell at it. The wound closed, but was still an angry red. His vampiric healing would get rid of it, using up the rest of his meal from the previous night. The meal that should have just gone to keep him 'alive' and clinging to what sanity he had left.

Moving to his private potions room that had been quickly rebuilt after the explosion he sat down and waited for his abilities to heal the wound. The pain, such that would incapacitate anyone else, merely annoyed the old Ex-Death Eater. Next he summoned bandages and wrapped his stomach until the wound could not be seen, and it would stop any leakage in case it reopened, however unlikely that was. He then repaired his under shirt, and robes, cleaning and freshening them before buttoning up his outer clothing. He took a breath and then stood. Pointing his wand at the fireplace he lit a fire and summoned Dumbledore for the third time in as many days.

"Headmaster, I need to see you immediately." Dumbledore did not even reply, he just came out of the fire.

"My dear boy, what happened?" Dumbledore said as he looked on in concern.

"I got a knife embedded in my stomach by a dunderheaded student who wasn't paying attention, because another idiot student set a firecracker off near his knife. I'm sending them both up to you. That however, is the least of my concerns, I'll heal. I did, however, lose a great deal of blood."

Dumbledore's face darkened.

"As such I'd like to take the rest of the day off as well as tomorrow, not only to keep up appearances of being human and needing rest, but because I am tired and… thirsty."

Dumbledore looked at Snape and nodded. "Of course my boy. I could also donate some-"

"NO." Snape cut him off. "No. You know what blood of such high magical content can do to vampires. I could get addicted to it. I'd only ask before a fight Albus, or if I… One was dying. Students, stuff off the ground from their excuses of duels, I don't have to worry about. You are another story. You're…aged. "

Dumbledore smiled. "Well I may look 90 but I am over 130." He chuckled to himself. "Take a couple days off, I'll cover potions for you. Just be sure to walk around a bit."

Snape nodded as he got up to go to his quarters. Dumbledore patted him on the back and went to grab the Potion Master's lesson plans. Too tired to do anything else, Snape threw his ruined robe and under clothing into the pile of clothes that was picked up each Wednesday for washing. He fell into bed; completely forgetting that the blood McGonagall gave him was in the robe.