This is my stab at a Good Omens FanFiction. Not sure where this will go yet but we will see.

"I said, that one went down like a lead balloon."

Aziraphale looked round. Standing next to him was a young, handsome demon with a distinctly snake-like appearance. It couldn't be the same one, could it?

…

Sometime before (although time isn't invented yet) …

Before there was earth, there was just heaven. It spanned the infinite skies of the universe and was as perfect and peaceful as a lake. But trouble was stirring, though few could sense it.

Crawley was looking out over the expanse of nothing outside the window. There were windows in heaven, and doors, but nothing quite made sense in the architecture of the place. This was Crawley's favourite window. It was in a secluded and quiet spot, where he could relax unobserved. It was also near the collection of one of the most random creations, pot plants. Crawley rather liked pot plants.

He heard a rustle. A golden-haired angel appeared through the pot plants and sat next to him. Crawley flinched. He had wanted to be alone.

"Hello Crawley," said the angel sweetly.

It was the kind of sweet your sister might use when she wants money off you. Crawley looked up at the angel warily. His hair fell right past his shoulders to his waist. Tangles hadn't been created yet so wearing your hair long was part of the fashion. Crawley had never fit into the fashion. But he thought he might look rather fetching with long hair.

"Lucifer," Crawley said warily.

"I've been thinking. I fancy a place of my own, heaven is a bit boring, don't you think? All I need is a few supporters and God will give us our own heaven."

Crawley muttered darkly. He did not believe a word this angel said. Apart from the bit about being bored. He would like to have somewhere else that he could visit. He wasn't sure if he wanted to stir up trouble yet though either. Crawley liked a good drama, but her preferred to watch from the outside, where the impact on him was minimal.

"So, you'll sign my peaceful petition to get another place for angels to live?"

Crawley signed. What else could he do? Lucifer was one of those angels who you couldn't help but follow. He was clever, charismatic. He was up to no good, but he made you want to be up to no good as well. He was also on his final warning from Gabriel and the Metatron. Lucifer had caused to much trouble already. Pestering important powers with his creation ideas, suggesting that parts of the ineffable plan were wrong, and should be changed. Hanging around with him was dangerous, and Crawley knew it. If he signed, maybe Lucifer would leave him alone and he wouldn't get into too much trouble.

…

Aziraphale was also approached by the revolutionary angel. He was quietly reading a book, another new invention, as unpopular as the pot plant. Aziraphale wanted to do a good job but wasn't sure quite how to make his voice heard.

He refused to sign the petition. Lucifer was not the right person to hang around with if you wanted to do well as an angel. He was noticed, as Aziraphale never was, but for the wrong reasons. Aziraphale wouldn't know how close he had come to damnation until a few days later, even as he sat, congratulating himself on his refusal.

…

Crawley was by the pot plants again. Banished. He couldn't be banished. He hadn't meant to fall. It was a whole new piece of vocabulary to him. He wasn't that interested in doing what God said, but he wasn't sure he wanted to be banished from heaven entirely. Heaven was dull, but it was all he knew.

"Crawley!"

Crawley recognised the voice of Lucifer. His friend. He wanted Crawley to come with him, to go down to the new place in glory and pride. But Crawley was regretting ever becoming friends with the angel and his cronies. Hastur, Ligur, Beelzebub, none of them were Crawley's type of people. Crawley hadn't even done anything wrong. Yet.

He ran. It seemed like the best course of action.

…

Aziraphale felt sorry for the poor souls being sent away from heaven. He wasn't sure why they were being sent either. All they had done was signed their names on a piece of paper.

He also wasn't sure why some of them seemed really rather proud of themselves, as though they had meant to fall all along. At the front of those being cast out of heaven was Lucifer, flanked by his seconds in command. But not all of them. One angel, the dark haired one who was never far from Lucifer's side, was missing.

As the angels left the gate of heaven, they became new entities entirely. One day, these beings would be called demons, but the name had not been decided yet. Horns sprouted from heads, animals of the like that Aziraphale had never seen before appeared among them, on them. They were the fallen, and they looked it.