A/N - Harry Potter characters are JK Rowling's, Rivers of London characters are Ben Aaronovitch's. If you haven't read Rivers of London, seriously, go buy the books, they are wonderful. Aleister Crowley was a real person. I do this for fun, I'm nowhere near good enough to do it for a living. I don't make any money out of it, but would encourage anyone to buy the HP and RoL books.

Prologue – Once Upon Your Dead Body

They never saw it coming. If they were being honest with themselves, they probably knew that their sordid affair would carry a price, be that a divorce or two, snide comments at work if it was ever discovered, the nib of guilt that would always reside somewhere in both of them. They never expected it would quite literally be the death of them. But then, who does.

They arrived at the secluded car park full of lust, looking for excitement, the thrill of the illicit, the spark of something that they were both missing with their partners. She got there first, sitting, waiting, longing for him to join her so they could lose themselves in their debauchery. It was like they were the first to have had the idea of a secret tryst. Not for them the knowledge that people of their persuasion had been doing that very thing since time immemorial.

What they got was a classic case of wrong place, wrong time.

They never saw their attackers coming. By the time he had heard a pop and sensed the presence of another, it was too late. The unholy sight before him had raised what he thought was a stick, uttered a phrase which sounded like Abracadabra and then a flash of green light saw his mistress fall to the ground, eyes open in final wonder. She never even had the time to scream.

He felt, rather than saw the presence. It was cold. So so cold. He felt a spectral mouth cover his and tried in vain to shout, he tried to rail against the grotesque perversion of a kiss he was somehow experiencing. His last rational thought was of the blistering cold he could feel course through his body. Then it was over. The body remained, but the soul departed.

The tall pallid skinned freak who had killed the woman was kneeling over her body, reciting some ancient incantation. The apparition which had kissed the man had vanished leaving the tall spectre with the two victims. In its place, an orb of light, conjured by the tall one. Oddly vibrant red eyes took in the sight of the husk before him. A few more words in a language which, had anyone heard, they wouldn't understand.

The man's body was covered by now. A black film which seemed to radiate evil. A wave of the stick and like some kind of sentient fluid the film started to seep into the recumbent man at the same time as the bizarre orb lowered and sank into his head. The body glowed with a black light before fading. The tall ghoul's incantation ended and there was silence. There was no birdsong in the air, there were no scurrying movements of small animals in the undergrowth. It was like the area surrounding could sense the evil being done and wanted no part of it.

"Our deal is one" said the tall.

The man's body jerked once, twice. Then, a scream pierced the surrounding air. He rose to a seated position, lifting his arms and examining them as if for the first time. There was something he had to do, he thought, but could not remember what it was. A tightness around his chest reminded him. Ah yes, breathe. That was it. When you had spent so many years as a wraith, it was easy to forget the basics. Finally, with his breathing under control, what was until recently a fairly normal man, spoke. It was a voice similar to the one he had woken up with that morning, when plans for a secret tryst were made, before his lover was slain and before the soul which previously inhabited the body was torn out. Similar, but not the same. There was a darkness to the voice now.

"I was right. Death left me alone. There was no God wih me" he rasped. The voice was not his own, he thought. He did not sound like this the last time he remembered speaking, That said, the last time he remembered speaking was some 60 years previously when he spoke to Eliza, his last follower, and the one who helped his spirit wander all these years. He wondered what happened to her. "But now I am back. Once again the Aeon of Horus is upon us."

"No" the other said. "The Age of Voldemort is upon us". He stood, looking down at the other. "Remember our deal. I have returned your spirit to a body, you will keep my soul shard safe. If you don't, having your spirit ripped from the new vessel I have found for you will be the least of your problems." The glowing red eyes fixed on the other man, who was now sitting up and looking around in wonder.

The being containing the reincorporated spirit of the darkest magician of the modern age as well as the soul shard of the darkest wizard looked at the embodiment of evil before him. "Yes, Lord Voldemort. I will not renege on our deal".

In his past life he had been many things. He had been a spy, he had been a revolutionary, he had been a prophet and he had been a mage. What he had been more than anything was a believer. He believed in the occult. He believed he was a black magician. He believed he was chosen to be something special.

His resurrection proved that he was. This was a rebirth indeed. Aleister Crowley had spent too long in an unknown spectral plane, the same plane that the revenant of Thomas Marvolo Riddle, the self styled Lord Voldemort had encountered.

Crowley knew he had magic in his blood. Voldemort however, was magic. He was a magical being, a magical construct. It was the darkness in Voldemort which drew the wraith of Crowley to him.

The rest, as they say, was history...