<blockquote>"They’d been scheduled to meet on Tuesday, but Crowley hadn’t shown. He’d left a message, short and to the point, explaining that he’d had some things to do, and at any other time Aziraphale might have been offended at being stood up. But he wasn’t. Instead, he found himself worrying. He couldn’t name it, but things – in a general sense – weren’t as they should be. It was like looking at a design with the wrong dimensions, or an equation missing a crucial integer.
Something about the way he'd looked...
“Oh, honestly,” Aziraphale said to the empty room, and he reached up for his coat.
Or:
Crowley has an existential crisis. Aziraphale attempts to pick up the pieces.</blockquote>