The shop that he steps carefully into is quiet save for the tiny bell that jingles as the door swings shut. He glances around quickly, taking in the warm lighting, the shelves lined and piled and stacked with books of all ages. There's a new paperback peeking out from behind a tome that must be at least a few centuries old, all crackled spine and warped, yellow pages.

The musty odor that surrounds him is not unpleasant, but it wraps so thickly around him that Castiel has to take a few moments to discreetly cough into his elbow. Something flickers in his peripheral vision, and he turns in time to get another glimpse of sweater through several haphazard stacks of what look like dictionaries.

The next thing he spots is a pair of narrowed eyes glaring at him from between some nearby shelves. They watch Castiel like he's about to attack the books and start shredding them at any moment. He runs his fingers across the titles of several covers on the shelf before him, reading them halfheartedly. A low huff comes from their owner.

When Castiel picks up one of the books - a bible from 1603 - the shopkeeper sighs loudly in an irritated manner, like Castiel has committed some grievous offense for daring to consider a purchase.

It is the confirmation he needs, and he lets his grace settle placidly throughout the room.

The eyes narrow quite a bit more. He puts the book back.

"Aziraphale," Castiel says and steps around the bookshelf to meet the other angel face-to-face.

Aziraphale doesn't so much as grin, only stares at Castiel with a look of mild annoyance. "Why are you here?"

The other angel did not smile, so neither does Castiel. He feels it though, deep in his vessel's bones, an emotion he does not know how to classify. "Brother. I cannot come for a visit?"

"None of you ever do. What has happened this time? Because if it's about the Antichrist, that's been handled already. Quite some time ago, too, I might add-"

"Aziraphale, that is not why I am here."

That catches his attention. The older angel's eyes are no longer thinned, the man's gaze centered fully on Castiel and what he might want. A small nudge of grace prompts Castiel to continue, and the feeling of a smile persists even if it is tinged with worry.

"The Righteous Man has been saved, and the Seals are being broken. Your assistance is needed."

Aziraphale's face, previously blank as a clean slate, slides into a frown. "I thought the Righteous Man wasn't supposed to be for quite some time. We've only just stopped one apocalypse, another shouldn't be starting-"

"Circumstances have changed." Castiel knows the answer isn't enough, knows that he has his own doubts even as he tries to stop Aziraphale's. Dean's face, his plea for Castiel not to make him torture, not to return him to the state he had been in during his last hours in the Pit, flashes before the younger angel's eyes even as Uriel's betrayal stings in his mind. He looks away from Aziraphale, lest he see Castiel's doubts.

He thinks he may have failed when Aziraphale's voice, softer, comforting, breaks the silence. "Very well then. We must get to work with all haste." A hand lands on Castiel's shoulder and he returns his gaze to meet the other angel's, eyes hard and clear.

Aziraphale looks all too understanding for Castiel to be entirely comfortable. His face too sympathetic. "Do not fear, Castiel," Aziraphale murmurs. "All will be well."

Aziraphale stopped an apocalypse. Aziraphale has seen the Garden and guarded it's gates. Aziraphale knows so much more than Castiel, knows Earth so much better for all the time he has spent on it, more than almost any other angel. He can do nothing but believe him.

And when Aziraphale smiles, just a small upturn of the corners of his mouth before he walks into the recesses of his bookshop, Castiel may or may not return it when he's not looking.