Disclaimer: JK Rowling, Warner Bros, Scholastic & Bloomsbury Books all own the Harry Potterverse. I make no money from this work of fiction.

Summary: Sixth year, SS/OC, OotP spoilers. Severus must play the game, and well, for the future of all. When someone returns from his past, he feels he must try to atone for his actions…The Last Sanguimagus is a sixth year fic with a particular emphasis on Snape and an original character, a new instructor at Hogwarts.

Author's Note: I have been developing this story for a few months now. While I have tried to do as much diligent research and careful planning as possible, I know that mistakes will still be made somewhere, and I apologize in advance. I have tried to consult the Harry Potter Lexicon and the books closely; however, as I have developed Blood Magic as a separate and distinct class of magic, it is only canon in the barest sense possible, though I have tried to incorporate it into the HP magic system.

One of the features of fanfic is that the author must take a "stand" on certain material and lean one way or the other regarding unclear details. In order to further the plot in the proper directions I've had to make choices about how to interpret occurrences in the books. I have no real way of concretely defending some decisions, but I hope you'll bear with them, and myself, as I attempt to navigate the perilous waters of the Potterverse.

I would like to thank my wonderful beta, Odd Doll, for her wonderful work. Any errors that remain are mine. I would like to thank my Britpicker, lianfire. Any errors that remain are mine.

And a warning: This is R rated for a reason. Though most of this fic is fairly harmless, in the tradition of full disclosure I would like to mention that there will be references to past non-con, angst, some torture, and, given the name of the fic, blood. If any of this offends you, please do not read this. And, if you are one of the few people left who has not read OotP, then I regret to inform you that this will, indeed, contain spoilers.

The Last Sanguimagus by valis2

Chapter One: Privet Drive

Today was his sixteenth birthday.

The obligatory greetings and cakes were already safely stashed away. Hedwig was dozing in her cage. The late afternoon sun had given way to twilight.

Harry lay sprawled upon the bed, not in the least bit bothered that he hadn't been called to the evening meal. This summer had marked the beginning of a new era of Harry-Dursley relations; after Moody's threat at the train station they had evidently decided that they were simply going to pretend that Harry did not exist. He was certain that they would ignore him whether he stayed or left.

In fact, he hadn't left. Not once.

Dumbledore's words still haunted him. He could not leave, not if Privet Drive afforded him his only protection. He would not, could not, endanger any more lives. He would stay where his mother's blood remained strong.

At first it had driven him crazy, cooped up in the spare room. It was maddening. He wanted to run around, walk the streets, visit Mrs. Figg—anything. But when he did think of leaving, he thought of Death Eaters threatening him, Mrs. Figg dead or dying—Dementors hovering nearby—

He couldn't do it. Privet Drive was safe, and it had to do.

Owls had arrived from Ron and Hermione, chatting about their summer so far, but he didn't feel like responding often. He didn't like thinking about Hogwarts while it was still so far away. His O.W.L. results had come in days ago and he hadn't even bothered to glance at them. He knew he'd see them soon enough, after all; Hermione's letter had mentioned a visit to Diagon Alley. He couldn't really avoid purchasing his school supplies, and, besides, that would mean school was beginning and his torture was over. He'd look at the scores then. He couldn't do it now.

For five weeks he'd been stuck in Dudley's second bedroom, and he couldn't let it bother him. He had to remain calm. He couldn't think about how much he wished the term was starting, how much he wished he could have stayed at Hogwarts all summer, how much he wanted to visit the Burrow…

Even as he thought of the enchanted house he pushed it out of his mind, pushed out the image of masked Death Eaters overrunning the Weasley home, green flashes of light pulsing from wands—

A noise from the cage distracted him, and he looked up. Hedwig was demanding to be let out. He opened the window, the cool rush of evening air swirling around the room, and she hopped to the ledge, giving him an affectionate nip as she swooped off into the night.

He sighed and watched her go.

Every day seemed to run into the next, a slow grey blur, inching along. Hedwig had returned twice so far, delivering messages from Hermione and Lupin that he hadn't bothered to read yet. She'd left immediately after dropping the messages in his hand and receiving a few owl treats.

He wondered dimly when he'd showered last, and realised that he didn't care. Dull thoughts swirled in his head. He yawned and rubbed his eyes.

Suddenly he heard a tapping. He rolled off the bed and stumbled to the window, immediately recognising a letter from Hogwarts in Hedwig's beak. He opened the window and she gave him the heavy envelope before perching on the dresser.

He didn't want to open it, because it would make him think of his second, happier life, and he wanted to suppress those thoughts. Curiosity won out, however, as there might be some chance that there was an invitation to come back early. He tore open the creamy envelope and pulled out the letter. The first page was so familiar that he felt his heart squeeze with longing. Better put that aside. The second page was a list of school supplies. Then he stared, surprised.

There was a third page. His heart contracted. Could it be—could they want him to go home now—

Dear Mr. Potter,

A special course is being taught this year at Hogwarts. Professor Tanner will be instructing students in the art of Talismans and Amulets. This course will only be available to sixth and seventh year students. Should you desire to take this class the textbook is Protecting Yourself: The Defensive Art of Amulets by Protegia Sanctorum.

Yours sincerely,

It was signed by Professor McGonagall, Deputy Headmistress of Hogwarts. Even more surprising, however, was the handwritten note at the bottom of the page:

I took the liberty of signing you up for this class. It may come in handy. The signature of Albus Dumbledore appeared neatly underneath.

Dumbledore wanted him to take the class. He sank down onto the edge of the bed, still gripping the letter. He still couldn't leave Privet Drive. And now he was enrolled in this class…because Dumbledore thought that Harry needed to protect himself from the madness of his life. From the hopelessness of his future. As if—as if a talisman could stop the Killing Curse. Or even the Cruciatus Curse. No talisman could stand against Voldemort.

The room suddenly grew cold, and he shivered involuntarily. In the back of his mind lurked the connection to the evil that had killed his parents, that had hurt his friends, that had knocked Sirius through—

I won't think about this. I won't think about this. I won't give him the satisfaction—

It was either him or Voldemort—him or Voldemort—only one could live—

He sat still on the bed for a very long time, the only sound that of his racing heartbeat.