Do you give yourself over wholly...

He was done playing games, but he'd continue to play them because he had no other choice. Michael was of no use; he seemed content to wait, certain of the inevitability.

Zachariah knew better to count on inevitability; it was his business, after all. He got all the ducks in a row. His specialty, in fact. It required meticulous planning and subtle execution. Somewhere, something had gone wrong. They were the agents of fate; it should not have been possible. There was no such thing as chance and happenstance; there was only them. They were the embodiment of the Will and the Word, and nothing could come against them. And yet there it was: Dean Winchester had defied them, when, by rights, he should have be wholly bent to their will.

...to the service of God and his angels?

The majesty and might of heaven, leashed to the word of a mortal. It was intolerable, a perversion, that they should be fettered at the whim of this creature of clay. Unworthy of even glimpsing the breadth and beauty of their greater plan- who was he to question it? Who was he to subvert it? The very idea was profane to the last.

Yeah, exactly. / Say it.

Castiel. It always came down to Castiel, and even that was an impossibility. He had been such a small part of the plan, but a necessary one. Castiel was the chosen liaison. It was as inherent to the plan as the Winchesters themselves. Zachariah had never questioned it, never worried about it. Castiel's role was miniscule as it was important. The rebellion of a lower-order angel was inconceivable- at least in any way that mattered. Even the rebellion of that wretched girl and the treachery of the fool Uriel had merely been part of the larger plan. They could no more subvert the Will and the Word than the planets and stars could defy gravity. They were subject to it even as they were themselves were a part of it.

Not even Lucifer could break free.

I give myself over wholly...

Zachariah had been troubled at the first sign of Castiel's sympathies, and had taken care to see them corrected. But he had not been unduly concerned; there were plans within plans the likes of which not even the foot soldiers could conceive. He had been been lulled by inevitability. And look where that had left him- reduced to trying to sway the mind of a man. Dean Winchester would not be swayed by reason- the pathetic little nothing suffered himself to be a champion of humanity in this war, as if they needed or deserved such a thing, as if they mattered. They would be given back the Garden and reborn as innocent. Mere curiosities, kept safe in their zoo, unburned by the small measures of Will granted to them by the Father.

And if Dean would not be swayed by reason, Zachariah was fully willing to sway him by might.

...to serve God and you guys.

It shouldn't be necessary. They'd had him. It had been the Carte Blanche of consent. No need for anything more; in the absence of God, there were only his angels, the living embodiments of his Will and his Word. Well, a Will and a Word anyway. But it was absolute. Nothing should have been able to come against them.

You swear to follow his will and his word as swiftly and obediently as you did your own father's?

Except that it had. The damnable vagaries of human tongues had seen to it that Dean's loyalty had been sworn to God and to Castiel...or at least, to whomever Castiel served. Castiel, who managed to rebel when it was not possible. Castiel, who sided with humanity, and Castiel, who would not stay dead.

It should have stayed simple, even with his rebellion. And yes, the rising of Lucifer had gone off without a hitch. Dean's presence could not have changed anything and did not change anything. A swimmer could not turn back the tide.

But something did. They subverted the Word and the Will, and that should not be possible. The angels, the messengers, were the only agents of the Will. There was no other. That was as it had always been.

And now? Now killing Castiel wouldn't matter, though it would be satisfying. It was done. The plan had shattered, and it was up to him to force it all back together.

Yes, I swear.

He would see to it that it was inevitable, and that it stayed that way.