[He sighs softly, more than a little exasperated.]

Sam Winchester is my chosen vessel, yes. He was always meant to be mine — and for a long time, he was. But... it seems this place has trapped me as much as it has you. And in the middle of my crucial work, at that.

[The shake of his head, and he takes a short walk around the room, studying the interesting little markings of an individual who once existed in this place. As he walks, his figure morphs into the likeness of Sam Winchester, in his too-white suit and neatly kept hair. He's so very different than the Sam in the thrift store — imposing, quietly dangerous, his back straight and not so hunched in and defeated. Raw power, in another world.]

Now, I'm under the surface.

I can only speak to you like this, my child. Much like you, my vessel has too much say over our body.