Disclaimer: I neither hold nor claim any rights to either Harry Potter or Hellsing. Credit for both goes to their respective authors. This is a work of fan fiction only.

Prologue

Harry Potter, the saviour of the wizarding world, turned up for work as usual, his features masked by the obscuring charm on the hood of the navy blue trench coat that was the standard uniform of the Unspeakables. As he passed through the various chambers of the Department of Mysteries some of his colleagues greeted him by his codename, which was all anyone knew of him, since the operatives real names were never recorded. There were no contracts, no signed oaths of secrecy, if you were accepted it was by word and your first task was to obliviate your interviewer of your own identity.

All in all, it was an ideal environment for a man who was over 40 years old but still didn't look a day over 18. Harry knew that to show his face in public would invite media attention at the very least, and a host of challengers for the power of the elder wand at worst. Not that anyone would be able to take the wand from him, since it had been absorbed into his body when he held all three hallows shortly after the battle of Hogwarts.

Walking into his assigned work area, the death chamber, he thought once more about how ironic it was that he would be working here of all places. The veil spoke to him in its usual whisper, a greeting to an old friend, and he thought he could hear the voices of loved ones long since lost.

He was still lost in contemplation when one of his colleagues gave him a heavy handed pat on the shoulder, and he tripped forward right through the veil, which glowed a bright red for a minute and then subsided. The shocked unspeakable who had greeted him reported the incident immediately, and a small plaque was added to the wall of lost operatives. That was all anyone in the Department ever got. It was simply safer if no-one knew anyone beyond their work.

Harry fell to his knees on a cold, dirty wooden floor in a poorly lit room. He was aware of what had happened and was rather surprised that he wasn't dead. 'Well, then again...' he thought to himself as he concentrated for a second, causing a ball of light to rise from his hand clearly illuminating the dingy cellar he had found himself in.

Clearing his mind, aware that there might be differences in the reality he had apparently landed in, he allowed his senses to spread out, looking for familiar touches of magic, to find nothing. Oh there were some hints of old magic, in particular a lot of blood magic, but nothing to indicate a thriving community of wizards and witches.

The only thing out of place that he did sense was something very familiar. 'Vampire' he thought as he searched for a way out of the cellar.

Alucard casually strolled out of the door of the building he had cornered the latest target in, his .454 Cassull still smoking slightly. He watched as the fleeing vampire charged towards the pair of Hellsing personnel standing guard over his master, the young Integra Hellsing. The two guards raised their weapons to fire, as did Alucard, as the freak vampire charged towards them, fangs bared and ready to strike, when two things suddenly happened. Firstly, a man appeared behind the vampire, a long bladed Katana already drawn and reaching the tail end of its swing. Secondly, the vampire's head lolled sideways from its body and fell, cut cleanly from the neck. The body and head turned to ash a moment later and the three armed Hellsing personnel trained their weapons on the newcomer.

"Sorry about that" said the figure in the trench coat, inwardly chuckling that he had introduced himself with the same words as Hagrid, almost thirty years previously. "Cut it a little fine...". He straightened, flicking his sword to clear the drops of blood from the blade, before sheathing it inside his coat, although there was no visible scabbard and the sword didn't appear to actually affect the flowing drop of the coat.

Alucard examined the figure for a moment, before raising his head, a chuckle bursting from deep within him, quickly growing to a deep rolling laugh. "A human taking on a vampire by hand, and so very neatly too. I love it!" he roared. The newcomer turned to face him, and then back to the obvious leader.

"Is he with you? Because if he's bothering you I'd be happy to help."

This time it was Integra who laughed, a cold mirthless laugh. "I would like to see you try. But yes, he is with me, and I would appreciate it if you did not give him cause to coat the street with your remains." She folded her arms and looked critically at the newcomer. "Now show yourself and explain who you are and what you are doing here." she ordered.

Harry shrugged, reaching up and pulling his hood down, showing his youthful face. "My apologies. I sensed the two vampires and had intended to take them both out. My name is Harry Potter and I came here to protect whoever the vampires were after. It seems that I might not have been needed. As for killing me, I would be highly amused if your pet over there is in fact capable of killing me."

Alucard snarled gleefully, a wicked smile spreading across his face as he raised his gun, aiming at the newcomer. "Come on then boy! If you think you can take me!"

"Alucard!" shouted Integra, "Stand down! We do not kill humans unless necessary." Turning to Harry she continued "I would be very interested to know how you arrived here, I'm quite sure that you weren't there one second and were the next."

Standing up straighter, out of his ready posture, Harry bowed slightly to Integra "That, my lady, is rather a long story. May I suggest we continue this discussion somewhere less public?"

Integra looked at him for a minute, before nodding and turning to walk back to her car. Harry caught up and walked alongside her whilst Alucard took up a guard position behind and between them. After a short journey to the Hellsing estate, Harry found himself sitting across from Integra at her desk, Alucard the only other presence in the room, and giving her a rough description of his arrival and the events leading to his interference in Alucard's hunt.

"So yes, I sensed two vampires and assumed they were hunting, so I decided to intervene before anyone could be harmed."

"And how precisely did you do that? I'm quite certain that humans cannot teleport, or become invisible."

Harry grinned. This was the part he'd been looking forward to. Explaining magic to a muggle and vampire with no statute of secrecy. "Simple my lady, magic."

Nothing could be heard for a few moments until, growing slowly until it filled the mansion, the sound of a vampire laughing hysterically rang out.

Author's Note: This is the prologue to an idea I've been writing for a while. This is the first fic I've got to a point where I'm happy that I can publish it and have enough material to finish it. It will be rated M just in case, since Hellsing is such a violent genre, and there may be some minor adult sequences. The chapter structure will broadly follow events from the Hellsing (Ultimate) anime, so Millenium not Incognito, but each chapter will probably be a subset of an episode.

I'm genuinely interested to know what people think, so please leave reviews. Having said that, I won't appreciate flames but I am more than happy to take on constructive criticism.

The prologue has a few humorous elements and I intend to maintain a little humor in keeping with the Hellsing anime, but for the most part it will be fairly serious.