Aziraphale immediately jumps to attention, whiplash between the moments and emotions having to wait until later. He knows that figure, though it takes him an extra second to recognize him in a place that was, until mere seconds ago, filled with joy, music and dancing.

How many things can happen in one night? How many times--

He looks at Crowley, then stares at the Duke, not speaking, but wondering if any demon or angel would attempt to attack them directly after the trials. Had they seen through it? Did they know? Is this one alone?