Crowley had time to take in three things when he opened the door to Aziraphale’s bookshop. First, that Hastur had not gotten any less revolting since the last time Crowley had seen him. Second, that their body swapping stunt hadn’t bought anywhere near as much time as he’d expected. Third, that the splash of water flying towards his face was very unlikely to have come from the local duck pond.
Even as he started to recoil, he knew he wouldn’t be fast enough. The worst part, he mused with a sense of detached horror, was that this meant they’d figure it out. It wouldn’t take a genius to put things together, once Crowley was reduced to a puddle of sodden clothes and a wisp of steam. Heaven and Hell would realise they’d pulled some kind of trick.
After he was gone, they’d come for Aziraphale.
Time slowed to a crawl. He twisted, trying to buy time to come up with a way out, to imagine an outcome where the sparkling droplets arcing towards him didn’t catch him across the chest. No time. No options.
There was a thunderous roar, a shattering crack, and the overpowering scent of ozone. Gravity tilted the ground out from underneath him… and then stopped.
Crowley’s eyes fluttered open, ears ringing and head spinning.
Aziraphale stood over him. The angel was wrapped around him, holding him up with one arm behind his waist and the other supporting his head. Crowley blinked at him, disoriented. Everything was too bright. White feathers swam in his vision behind the angel’s face.
“Crowley…” Aziraphale breathed, eyes wide with shock and inhumanly blue.
Crowley clawed his way out of the fog of confusion, tightening his grip on the angel’s jacket. Awareness snapped back in. They were in the doorway, Aziraphale’s back to the open door. His wings were out, one curved protectively around Crowley and the other angled to block the door.
Water dripped steadily from the tips of the gleaming feathers, falling to pool on the doorstep.
Crowley’s jaw dropped open. “Angel… how…”
Aziraphale moved the hand behind his head around to cup Crowley’s face. His eyes, still bright with otherworldly intensity, darted over the demon’s face, and his lip trembled.
“I knew it,” crowed Hastur’s voice.
Aziraphale’s face went utterly blank, hardening to marble. Crowley sucked in a breath, startled by the sudden change, but the angel’s fingers stroked over his cheek, soothing and gentle. Aziraphale closed his eyes, and briefly pressed his forehead against Crowley’s.
Then he straightened. And turned.
He took a step towards Hastur, and a surge of chilling ethereal power made Crowley stagger backwards. One step, then another, the angel’s feet struck the ground with the sound of a deafening bell. Invisible power gathered around him, righteous and malevolent, and as he walked onto the street his wings stretched wide.
“I do believe,” he said, voice terrible and vast and almost painful to Crowley’s ears, “you’re at the wrong shop.”
Hastur stared at the angel, at his flaming blue eyes, and crackling power, and the holy water still dripping from his wing.
Then the demon disappeared with a terror-stricken pop.