Angels do not make stories.
Demons can lie--in fact, they are known for it. Angels can prevaricate, and do. (Some of them more frequently than others.) Of course they remember, with a greater clarity and depth than any human being, and can recount history with wit as well as accuracy. (Well, at least Aziraphale does, according to Crowley.) But they cannot make things up.
That is a gift which God shared only with humans.
Humans can lie, and prevaricate, exaggerate, obfuscate, hyperbolise, forget, confuse, and outright refuse to face facts. They are often wrong about matters of history and wrong-headed in matters of interpretation. But they make things up. It is one reason why they are so fascinating to both Aziraphale and Crowley.
Aziraphale read the Epic of Gilgamesh when the imprints of the stylus were still fresh on the first tablets. He read all the various versions of what was later known as "the Bible" and was at first appalled at the difference between the official text and what had actually happened, and then fascinated by it. He collected myths as some people collect Bakelite, as he began to collect books when being a bookseller in the capital city of a little island with very influential inhabitants became the best way to carry out his earthly duties.
Crowley was never as mad about books, but he was a bigger fan than Aziraphale of theatre. He not only memorized most of Shakespeare's plays by seeing them live at the Globe, he soaked himself over the centuries in the dramas of Aeschylus and Sophocles, the spectacles of India and China, the masked dramas of Japan. Some of his quieter but fondly remembered moments of the 20th century involved Harold Pinter and Athol Fugard (although he dislikes musicals except for Sondheim, and later on, Hamilton). He's even done a few turns on the boards himself, usually as just a spear carrier or a cafe sitter. He relishes the intensity of theatre life, the little dramas that go on backstage in dark corners whilst something very different happens before the audience.
One evening in late autumn, when he's feeling more than a little sluggish, he indulges himself with a nap in snake form, using Aziraphale for his den. Aziraphale, in turn, is comfortably ensconced in a deep armchair with a handy footstool, a reading lamp to one side, a small table that just holds a tray of tea and biscuits to the other. He has been re-reading War in Heaven by Charles Williams for several hours, without any break, when Crowley eventually wakes up and slithers down to the floor. He snags a biscuit once he's back in human form and pours himself tea into the empty cup that now sits beside Aziraphale's.
"Why do you suppose," he asks, after a third biscuit, "angels and demons can't tell stories?"
Aziraphale turns two pages without answering, his eyes on the book; then sighs, and closes it, folding it between his hands in a way that says he has, reluctantly, finished it.
"Perhaps it's because we don't have, er, 'free will'." He says the last two words as if referring to something indelicate. "We only have our places in the Plan."
Crowley scratches his chin, which still feels a bit scaley. "The Plan's not irresistible, though. You and I proved that when we stopped the... you know." For Crowley, the aborted apocalypse is indelicate.
"Ah, but we only subverted the Great Plan, you know." Aziraphale smiles in that way that makes Crowley feel like sugar and cinnamon taste. "We were still carrying out the Ineffable Plan. I suppose we still are."
"Are you certain?" Crowley stretches out on the couch. "If there really is an Ineffable Plan, how can we be sure what it is?"
"Well--" Aziraphale frowns, and purses his lips. He looks very cute when he purses his lips (according to Crowley). "Do you believe we have free will, our kind?" he asks, after a fretful pause.
"I dunno, angel. Humans are pretty sure that they do, and look how much they mess things up. But they do tell stories."
"Wonderful stories." Aziraphale sounds wistful. He glances at the book still in his lap. "Even when they are wrong, they are, well, true."
Crowley nods. "How do they do that...."
For a few minutes neither angel says nothing. It is quite dark outside, and oddly quiet. Aziraphale idly munches the last biscuit on the plate.
"We could... try," he says at last, and trails off.
Crowley sits up. "Try what?"
Aziraphale does that thing where his eyes look everywhere but at Crowley, pausing on the book still in his lap. "Try... telling a story. Making something up."
Crowley snaps his fingers, inadvertently plunging all of Soho into complete darkness, then snaps them again, undoing it. "That's a capital idea, angel! Why don't you start?"
Aziraphale stutters. "Oh, I--I wouldn't know where to start--"
"Yes, you do." Crowley slides down the couch, closer to the angel. "The same way humans do! With 'Once upon a time'."
"Ah!" Aziraphale sits up a little straighter in the deep armchair. "Once upon a time, there was... there was...."
"There was war in heaven," Crowley said, pointing at Aziraphale's book. "Michael and his angels against the serpent and his armies." He grins, not very pleasantly. "And we lost."
"Michael and Gabriel banished the defeated angels," Aziraphale continues. "They were exiled from heaven and founded a kingdom under the earth, in the basement of things, away from the angels and from the rest of God's creation. But God sent one angel to keep an eye on her newest creation, humans, and the lovely garden she had made for them." The faint smile that had crossed his face at the mention of the garden faded into sadness. "And the angel did a terrible job."
"The angel," Crowley said, "was generous and helpful to the first humans, even after the demon who was dispatched to make trouble with them had interfered. And the angel was kind and generous and sometimes even helpful to the demon, too."
"But, Crowley!" Aziraphale burst out. "We're not really telling a story--we're rehearsing a history. It's not the same!" He clutched the book to his chest as if the creased and faded paperback were the most precious of objects, more precious than crepes.
Crowley licked his lips nervously, with a tongue that was a bit too long and narrow. "Well, let's start over, then. How about this: Once upon a time, the world was supposed to end but didn't. Because of a boy who cared too much, and angels who cared too little, and demons who were basically lazy, and one demon who... fell in love with the angel who had supposedly been his enemy for six thousand years."
Crowley's eyes had turned gold all through, the whites gone, the black pupils split wide with emotion. Aziraphale's mild blue eyes had turned into swirls of glittering heat, as if a bolt of lightning flashed across a perfectly cloudless summer sky. Blue eyes gazed into golden eyes for what was, subjectively, several aeons, while objectively it lasted about five minutes. Neither of them blinked or breathed during this time.
"And all the time," Aziraphale said softly, his wings beginning to rustle, "the angel believed that he loved the demon who had become his friend without requital, and under the judgment of God."
Crowley stood up and stretched out his hand. His wings stretched out, too, blacker than the cloudy night sky and glistening like starlight.
"Then one day, when the apocalypse had been staved off and all the other angels and demons had gone back home, the angel and the demon left on earth realized that, whether it was part of a divine plan or not, they were in love and belonged together."
Aziraphale rose and took the proffered hand, his wings mantling round him to brush Crowley's. "And they decided to live happily ever after."
As they kissed in Aziraphale's sitting room (and it didn't stop with kissing), God laid down her last card on the pile and grinned.
"Well, hot damn. I finally won at Solitaire."