The being that sauntered vaguely downwards and the one that fell

Aziraphale should have known he couldn't trust Heaven or Hell, and he certainly couldn't trust the Metatron.

The only being he could trust was still on earth doing God knows what but he could never go back to him.

But he did need someone to help get him out of the mess he had accidentally landed in.

............

Crowley knew that Heaven and Hell could never be trusted, but that didn't stop Aziraphale from leaving him.

So he went through his days feeling like an empty shell of a being until a certain cherub faced angel showed up at his door saying they need his help saving a certain someone.

Basically Aziraphale is going to fall, Muriel is the only one trying to catch him, and Crowley is trying to nurse his feelings back to some semblance of normal until an angel shows up at his door asking for help.